Encoding.GetBytes Método
Definición
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres en una secuencia de bytes.When overridden in a derived class, encodes a set of characters into a sequence of bytes.
Sobrecargas
GetBytes(Char[]) |
Cuando se reemplaza en una clase derivada, codifica todos los caracteres de la matriz de caracteres especificada en una secuencia de bytes.When overridden in a derived class, encodes all the characters in the specified character array into a sequence of bytes. |
GetBytes(String) |
Cuando se reemplaza en una clase derivada, codifica todos los caracteres de la cadena especificada en una secuencia de bytes.When overridden in a derived class, encodes all the characters in the specified string into a sequence of bytes. |
GetBytes(ReadOnlySpan<Char>, Span<Byte>) |
Cuando se invalida en una clase derivada, codifica en un intervalo de bytes un juego de caracteres a partir del intervalo de solo lectura especificado.When overridden in a derived class, encodes into a span of bytes a set of characters from the specified read-only span. |
GetBytes(Char[], Int32, Int32) |
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la matriz de caracteres especificada en una secuencia de bytes.When overridden in a derived class, encodes a set of characters from the specified character array into a sequence of bytes. |
GetBytes(String, Int32, Int32) |
Cuando se invalida en una clase derivada, codifica en una matriz de bytes el número de caracteres especificado por |
GetBytes(Char*, Int32, Byte*, Int32) |
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres a partir del puntero de caracteres especificado en una secuencia de bytes que se almacenan a partir del puntero de bytes especificado.When overridden in a derived class, encodes a set of characters starting at the specified character pointer into a sequence of bytes that are stored starting at the specified byte pointer. |
GetBytes(Char[], Int32, Int32, Byte[], Int32) |
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la matriz de caracteres especificada en la matriz de bytes especificada.When overridden in a derived class, encodes a set of characters from the specified character array into the specified byte array. |
GetBytes(String, Int32, Int32, Byte[], Int32) |
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la cadena especificada en la matriz de bytes especificada.When overridden in a derived class, encodes a set of characters from the specified string into the specified byte array. |
GetBytes(Char[])
Cuando se reemplaza en una clase derivada, codifica todos los caracteres de la matriz de caracteres especificada en una secuencia de bytes.When overridden in a derived class, encodes all the characters in the specified character array into a sequence of bytes.
public:
virtual cli::array <System::Byte> ^ GetBytes(cli::array <char> ^ chars);
public virtual byte[] GetBytes (char[] chars);
abstract member GetBytes : char[] -> byte[]
override this.GetBytes : char[] -> byte[]
Public Overridable Function GetBytes (chars As Char()) As Byte()
Parámetros
- chars
- Char[]
Matriz de caracteres que contiene los caracteres que se codifican.The character array containing the characters to encode.
Devoluciones
- Byte[]
Matriz de bytes que contiene los resultados de codificar el juego de caracteres especificado.A byte array containing the results of encoding the specified set of characters.
Excepciones
chars
es null
.chars
is null
.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar una matriz de caracteres, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode a character array, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( array<Char>^chars, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
array<Char>^myChars = gcnew array<Char>{
L'z','a',L'\u0306',L'\u01FD',L'\u03B2',L'\xD8FF',L'\xDCFF'
};
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode the entire array, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, u7 );
PrintCountsAndBytes( myChars, u8 );
PrintCountsAndBytes( myChars, u16LE );
PrintCountsAndBytes( myChars, u16BE );
PrintCountsAndBytes( myChars, u32 );
}
void PrintCountsAndBytes( array<Char>^chars, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( chars );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( chars->Length );
Console::Write( " {0,-3} :", iMBC );
// Encode the array of chars.
array<Byte>^bytes = enc->GetBytes( chars );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' };
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode the entire array, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, u7 );
PrintCountsAndBytes( myChars, u8 );
PrintCountsAndBytes( myChars, u16LE );
PrintCountsAndBytes( myChars, u16BE );
PrintCountsAndBytes( myChars, u32 );
}
public static void PrintCountsAndBytes( char[] chars, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( chars );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( chars.Length );
Console.Write( " {0,-3} :", iMBC );
// Encode the array of chars.
byte[] bytes = enc.GetBytes( chars );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myChars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), ChrW(&H03B2), ChrW(&HD8FF), ChrW(&HDCFF)}
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode the entire array, and print out the counts and the resulting bytes.
PrintCountsAndBytes(myChars, u7)
PrintCountsAndBytes(myChars, u8)
PrintCountsAndBytes(myChars, u16LE)
PrintCountsAndBytes(myChars, u16BE)
PrintCountsAndBytes(myChars, u32)
End Sub
Public Shared Sub PrintCountsAndBytes(chars() As Char, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(chars)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(chars.Length)
Console.Write(" {0,-3} :", iMBC)
' Encode the array of chars.
Dim bytes As Byte() = enc.GetBytes(chars)
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
'System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Comentarios
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe llamar a la versión de cadena del GetBytes método.If your app handles string inputs, you should call the string version of the GetBytes method.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Consulte también
Se aplica a
GetBytes(String)
Cuando se reemplaza en una clase derivada, codifica todos los caracteres de la cadena especificada en una secuencia de bytes.When overridden in a derived class, encodes all the characters in the specified string into a sequence of bytes.
public:
virtual cli::array <System::Byte> ^ GetBytes(System::String ^ s);
public virtual byte[] GetBytes (string s);
abstract member GetBytes : string -> byte[]
override this.GetBytes : string -> byte[]
Public Overridable Function GetBytes (s As String) As Byte()
Parámetros
- s
- String
Cadena que contiene los caracteres que se van a codificar.The string containing the characters to encode.
Devoluciones
- Byte[]
Matriz de bytes que contiene los resultados de codificar el juego de caracteres especificado.A byte array containing the results of encoding the specified set of characters.
Excepciones
s
es null
.s
is null
.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar una cadena o un intervalo de la cadena, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode a string or a range in the string, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( String^ s, Encoding^ enc );
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String^ myStr = L"za\u0306\u01FD\u03B2\xD8FF\xDCFF";
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console::WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
void PrintCountsAndBytes( String^ s, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( s->Length );
Console::Write( " {0,-3} :", iMBC );
// Encode the entire string.
array<Byte>^bytes = enc->GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s->ToCharArray(), index, count );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( count );
Console::Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
array<Byte>^bytes = gcnew array<Byte>(iBC);
enc->GetBytes( s, index, count, bytes, bytes->GetLowerBound( 0 ) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String myStr = "za\u0306\u01FD\u03B2\uD8FF\uDCFF";
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console.WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
public static void PrintCountsAndBytes( String s, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( s.Length );
Console.Write( " {0,-3} :", iMBC );
// Encode the entire string.
byte[] bytes = enc.GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintCountsAndBytes( String s, int index, int count, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s.ToCharArray(), index, count );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( count );
Console.Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
byte[] bytes = new byte[iBC];
enc.GetBytes( s, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myStr As String = "za" & ChrW(&H0306) & ChrW(&H01FD) & ChrW(&H03B2) & ChrW(&HD8FF) & ChrW(&HDCFF)
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the entire string:")
PrintCountsAndBytes(myStr, u7)
PrintCountsAndBytes(myStr, u8)
PrintCountsAndBytes(myStr, u16LE)
PrintCountsAndBytes(myStr, u16BE)
PrintCountsAndBytes(myStr, u32)
Console.WriteLine()
' Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the characters from index 4 through 6:")
PrintCountsAndBytes(myStr, 4, 3, u7)
PrintCountsAndBytes(myStr, 4, 3, u8)
PrintCountsAndBytes(myStr, 4, 3, u16LE)
PrintCountsAndBytes(myStr, 4, 3, u16BE)
PrintCountsAndBytes(myStr, 4, 3, u32)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(s.Length)
Console.Write(" {0,-3} :", iMBC)
' Encode the entire string.
Dim bytes As Byte() = enc.GetBytes(s)
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, index As Integer, count As Integer, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s.ToCharArray(), index, count)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(count)
Console.Write(" {0,-3} :", iMBC)
' Encode a range of characters in the string.
' NOTE: In VB.NET, arrays contain one extra element by default.
' The following line creates the array with the exact number of elements required.
Dim bytes(iBC - 1) As Byte
enc.GetBytes(s, index, count, bytes, bytes.GetLowerBound(0))
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'Encoding the entire string:
'System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
'System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
'
'Encoding the characters from index 4 through 6:
'System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
'System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
Comentarios
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Consulte también
Se aplica a
GetBytes(ReadOnlySpan<Char>, Span<Byte>)
Cuando se invalida en una clase derivada, codifica en un intervalo de bytes un juego de caracteres a partir del intervalo de solo lectura especificado.When overridden in a derived class, encodes into a span of bytes a set of characters from the specified read-only span.
public:
virtual int GetBytes(ReadOnlySpan<char> chars, Span<System::Byte> bytes);
public virtual int GetBytes (ReadOnlySpan<char> chars, Span<byte> bytes);
abstract member GetBytes : ReadOnlySpan<char> * Span<byte> -> int
override this.GetBytes : ReadOnlySpan<char> * Span<byte> -> int
Public Overridable Function GetBytes (chars As ReadOnlySpan(Of Char), bytes As Span(Of Byte)) As Integer
Parámetros
- chars
- ReadOnlySpan<Char>
El intervalo que contiene el juego de caracteres que se va a codificar.The span containing the set of characters to encode.
El intervalo de bytes en el que se van a contener los bytes codificados.The byte span to hold the encoded bytes.
Devoluciones
El número de bytes codificados.The number of encoded bytes.
Comentarios
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Se aplica a
GetBytes(Char[], Int32, Int32)
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la matriz de caracteres especificada en una secuencia de bytes.When overridden in a derived class, encodes a set of characters from the specified character array into a sequence of bytes.
public:
virtual cli::array <System::Byte> ^ GetBytes(cli::array <char> ^ chars, int index, int count);
public virtual byte[] GetBytes (char[] chars, int index, int count);
abstract member GetBytes : char[] * int * int -> byte[]
override this.GetBytes : char[] * int * int -> byte[]
Public Overridable Function GetBytes (chars As Char(), index As Integer, count As Integer) As Byte()
Parámetros
- chars
- Char[]
Matriz de caracteres que contiene el juego de caracteres que se va a codificar.The character array containing the set of characters to encode.
- index
- Int32
Índice del primer carácter que se va a codificar.The index of the first character to encode.
- count
- Int32
Número de caracteres que se van a codificar.The number of characters to encode.
Devoluciones
- Byte[]
Matriz de bytes que contiene los resultados de codificar el juego de caracteres especificado.A byte array containing the results of encoding the specified set of characters.
Excepciones
chars
es null
.chars
is null
.
index
o count
es menor que cero.index
or count
is less than zero.
o bien-or-
index
y count
no denotan un intervalo válido en chars
.index
and count
do not denote a valid range in chars
.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar tres caracteres de una matriz de caracteres, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode three characters from a character array, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( array<Char>^chars, int index, int count, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
array<Char>^myChars = gcnew array<Char>{
L'z',L'a',L'\u0306',L'\u01FD',L'\u03B2',L'\xD8FF',L'\xDCFF'
};
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, 4, 3, u7 );
PrintCountsAndBytes( myChars, 4, 3, u8 );
PrintCountsAndBytes( myChars, 4, 3, u16LE );
PrintCountsAndBytes( myChars, 4, 3, u16BE );
PrintCountsAndBytes( myChars, 4, 3, u32 );
}
void PrintCountsAndBytes( array<Char>^chars, int index, int count, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( chars, index, count );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( count );
Console::Write( " {0,-3} :", iMBC );
// Encode the array of chars.
array<Byte>^bytes = enc->GetBytes( chars, index, count );
// The following is an alternative way to encode the array of chars:
// byte[] bytes = new byte[iBC];
// enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' };
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, 4, 3, u7 );
PrintCountsAndBytes( myChars, 4, 3, u8 );
PrintCountsAndBytes( myChars, 4, 3, u16LE );
PrintCountsAndBytes( myChars, 4, 3, u16BE );
PrintCountsAndBytes( myChars, 4, 3, u32 );
}
public static void PrintCountsAndBytes( char[] chars, int index, int count, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( chars, index, count );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( count );
Console.Write( " {0,-3} :", iMBC );
// Encode the array of chars.
byte[] bytes = enc.GetBytes( chars, index, count );
// The following is an alternative way to encode the array of chars:
// byte[] bytes = new byte[iBC];
// enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myChars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), ChrW(&H03B2), ChrW(&HD8FF), ChrW(&HDCFF) }
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes(myChars, 4, 3, u7)
PrintCountsAndBytes(myChars, 4, 3, u8)
PrintCountsAndBytes(myChars, 4, 3, u16LE)
PrintCountsAndBytes(myChars, 4, 3, u16BE)
PrintCountsAndBytes(myChars, 4, 3, u32)
End Sub
Public Shared Sub PrintCountsAndBytes(chars() As Char, index As Integer, count As Integer, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(chars, index, count)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(count)
Console.Write(" {0,-3} :", iMBC)
' Encode the array of chars.
Dim bytes As Byte() = enc.GetBytes(chars, index, count)
' The following is an alternative way to encode the array of chars:
' NOTE: In VB.NET, arrays contain one extra element by default.
' The following line creates the array with the exact number of elements required.
' Dim bytes(iBC - 1) As Byte
' enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) )
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
'System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
Comentarios
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Consulte también
Se aplica a
GetBytes(String, Int32, Int32)
Cuando se invalida en una clase derivada, codifica en una matriz de bytes el número de caracteres especificado por count
en la cadena especificada, empezando por el elemento index
especificado.When overridden in a derived class, encodes into an array of bytes the number of characters specified by count
in the specified string, starting from the specified index
.
public:
cli::array <System::Byte> ^ GetBytes(System::String ^ s, int index, int count);
public byte[] GetBytes (string s, int index, int count);
member this.GetBytes : string * int * int -> byte[]
Public Function GetBytes (s As String, index As Integer, count As Integer) As Byte()
Parámetros
- s
- String
Cadena que contiene los caracteres que se van a codificar.The string containing the characters to encode.
- index
- Int32
El índice dentro de la cadena desde el que se va a iniciar la codificación.The index inside the string to start the encoding from.
- count
- Int32
Número de caracteres que se van a codificar.The number of characters to encode.
Devoluciones
- Byte[]
Matriz de bytes que contiene los resultados de codificar el juego de caracteres especificado.A byte array containing the results of encoding the specified set of characters.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar una cadena o un intervalo de la cadena, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode a string or a range in the string, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( String^ s, Encoding^ enc );
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String^ myStr = L"za\u0306\u01FD\u03B2\xD8FF\xDCFF";
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console::WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
void PrintCountsAndBytes( String^ s, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( s->Length );
Console::Write( " {0,-3} :", iMBC );
// Encode the entire string.
array<Byte>^bytes = enc->GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s->ToCharArray(), index, count );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( count );
Console::Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
array<Byte>^bytes = gcnew array<Byte>(iBC);
enc->GetBytes( s, index, count, bytes, bytes->GetLowerBound( 0 ) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String myStr = "za\u0306\u01FD\u03B2\uD8FF\uDCFF";
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console.WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
public static void PrintCountsAndBytes( String s, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( s.Length );
Console.Write( " {0,-3} :", iMBC );
// Encode the entire string.
byte[] bytes = enc.GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintCountsAndBytes( String s, int index, int count, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s.ToCharArray(), index, count );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( count );
Console.Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
byte[] bytes = new byte[iBC];
enc.GetBytes( s, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myStr As String = "za" & ChrW(&H0306) & ChrW(&H01FD) & ChrW(&H03B2) & ChrW(&HD8FF) & ChrW(&HDCFF)
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the entire string:")
PrintCountsAndBytes(myStr, u7)
PrintCountsAndBytes(myStr, u8)
PrintCountsAndBytes(myStr, u16LE)
PrintCountsAndBytes(myStr, u16BE)
PrintCountsAndBytes(myStr, u32)
Console.WriteLine()
' Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the characters from index 4 through 6:")
PrintCountsAndBytes(myStr, 4, 3, u7)
PrintCountsAndBytes(myStr, 4, 3, u8)
PrintCountsAndBytes(myStr, 4, 3, u16LE)
PrintCountsAndBytes(myStr, 4, 3, u16BE)
PrintCountsAndBytes(myStr, 4, 3, u32)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(s.Length)
Console.Write(" {0,-3} :", iMBC)
' Encode the entire string.
Dim bytes As Byte() = enc.GetBytes(s)
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, index As Integer, count As Integer, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s.ToCharArray(), index, count)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(count)
Console.Write(" {0,-3} :", iMBC)
' Encode a range of characters in the string.
' NOTE: In VB.NET, arrays contain one extra element by default.
' The following line creates the array with the exact number of elements required.
Dim bytes(iBC - 1) As Byte
enc.GetBytes(s, index, count, bytes, bytes.GetLowerBound(0))
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'Encoding the entire string:
'System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
'System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
'
'Encoding the characters from index 4 through 6:
'System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
'System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
Comentarios
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Se aplica a
GetBytes(Char*, Int32, Byte*, Int32)
Importante
Esta API no es conforme a CLS.
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres a partir del puntero de caracteres especificado en una secuencia de bytes que se almacenan a partir del puntero de bytes especificado.When overridden in a derived class, encodes a set of characters starting at the specified character pointer into a sequence of bytes that are stored starting at the specified byte pointer.
public:
virtual int GetBytes(char* chars, int charCount, System::Byte* bytes, int byteCount);
[System.CLSCompliant(false)]
[System.Security.SecurityCritical]
public virtual int GetBytes (char* chars, int charCount, byte* bytes, int byteCount);
[System.CLSCompliant(false)]
public virtual int GetBytes (char* chars, int charCount, byte* bytes, int byteCount);
[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(false)]
public virtual int GetBytes (char* chars, int charCount, byte* bytes, int byteCount);
[System.CLSCompliant(false)]
[System.Security.SecurityCritical]
[System.Runtime.InteropServices.ComVisible(false)]
public virtual int GetBytes (char* chars, int charCount, byte* bytes, int byteCount);
[<System.CLSCompliant(false)>]
[<System.Security.SecurityCritical>]
abstract member GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
override this.GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
[<System.CLSCompliant(false)>]
abstract member GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
override this.GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
[<System.CLSCompliant(false)>]
[<System.Runtime.InteropServices.ComVisible(false)>]
abstract member GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
override this.GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
[<System.CLSCompliant(false)>]
[<System.Security.SecurityCritical>]
[<System.Runtime.InteropServices.ComVisible(false)>]
abstract member GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
override this.GetBytes : nativeptr<char> * int * nativeptr<byte> * int -> int
Parámetros
- chars
- Char*
Puntero al primer carácter que se va a codificar.A pointer to the first character to encode.
- charCount
- Int32
Número de caracteres que se van a codificar.The number of characters to encode.
- bytes
- Byte*
Puntero a la ubicación en la que se iniciará la escritura de la secuencia de bytes resultante.A pointer to the location at which to start writing the resulting sequence of bytes.
- byteCount
- Int32
Número máximo de bytes que se pueden escribir.The maximum number of bytes to write.
Devoluciones
Número real de bytes escritos en la ubicación indicada por el parámetro bytes
.The actual number of bytes written at the location indicated by the bytes
parameter.
- Atributos
Excepciones
charCount
o byteCount
es menor que cero.charCount
or byteCount
is less than zero.
El valor de byteCount
es menor que el número resultante de bytes.byteCount
is less than the resulting number of bytes.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Comentarios
Para calcular el tamaño exacto de la matriz que GetBytes requiere para almacenar los bytes resultantes, llame al GetByteCount método.To calculate the exact array size that GetBytes requires to store the resulting bytes, call the GetByteCount method. Para calcular el tamaño máximo de la matriz, llame al GetMaxByteCount método.To calculate the maximum array size, call the GetMaxByteCount method. El GetByteCount método generalmente permite la asignación de menos memoria, mientras que el GetMaxByteCount método suele ejecutarse más rápido.The GetByteCount method generally allows allocation of less memory, while the GetMaxByteCount method generally executes faster.
Si los datos que se va a convertir están disponibles sólo en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, se debe usar el Decoder o Encoder objeto proporcionado por el GetDecoder o GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder object provided by the GetDecoder or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Consulte también
Se aplica a
GetBytes(Char[], Int32, Int32, Byte[], Int32)
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la matriz de caracteres especificada en la matriz de bytes especificada.When overridden in a derived class, encodes a set of characters from the specified character array into the specified byte array.
public:
abstract int GetBytes(cli::array <char> ^ chars, int charIndex, int charCount, cli::array <System::Byte> ^ bytes, int byteIndex);
public abstract int GetBytes (char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex);
abstract member GetBytes : char[] * int * int * byte[] * int -> int
Public MustOverride Function GetBytes (chars As Char(), charIndex As Integer, charCount As Integer, bytes As Byte(), byteIndex As Integer) As Integer
Parámetros
- chars
- Char[]
Matriz de caracteres que contiene el juego de caracteres que se va a codificar.The character array containing the set of characters to encode.
- charIndex
- Int32
Índice del primer carácter que se va a codificar.The index of the first character to encode.
- charCount
- Int32
Número de caracteres que se van a codificar.The number of characters to encode.
- bytes
- Byte[]
Matriz de bytes que contendrá la secuencia de bytes resultante.The byte array to contain the resulting sequence of bytes.
- byteIndex
- Int32
Índice en el que se inicia la escritura de la secuencia de bytes resultante.The index at which to start writing the resulting sequence of bytes.
Devoluciones
Número real de bytes escritos en bytes
.The actual number of bytes written into bytes
.
Excepciones
El valor de charIndex
, charCount
o byteIndex
es menor que cero.charIndex
or charCount
or byteIndex
is less than zero.
o bien-or-
charIndex
y charCount
no denotan un intervalo válido en chars
.charIndex
and charCount
do not denote a valid range in chars
.
o bien-or-
byteIndex
no es un índice válido para bytes
.byteIndex
is not a valid index in bytes
.
bytes
no tiene suficiente capacidad desde byteIndex
hasta el final de la matriz para alojar los bytes resultantes.bytes
does not have enough capacity from byteIndex
to the end of the array to accommodate the resulting bytes.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar tres caracteres de una matriz de caracteres, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode three characters from a character array, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( array<Char>^chars, int index, int count, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
array<Char>^myChars = gcnew array<Char>{
L'z',L'a',L'\u0306',L'\u01FD',L'\u03B2',L'\xD8FF',L'\xDCFF'
};
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, 4, 3, u7 );
PrintCountsAndBytes( myChars, 4, 3, u8 );
PrintCountsAndBytes( myChars, 4, 3, u16LE );
PrintCountsAndBytes( myChars, 4, 3, u16BE );
PrintCountsAndBytes( myChars, 4, 3, u32 );
}
void PrintCountsAndBytes( array<Char>^chars, int index, int count, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( chars, index, count );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( count );
Console::Write( " {0,-3} :", iMBC );
// Encode the array of chars.
array<Byte>^bytes = enc->GetBytes( chars, index, count );
// The following is an alternative way to encode the array of chars:
// byte[] bytes = new byte[iBC];
// enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' };
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes( myChars, 4, 3, u7 );
PrintCountsAndBytes( myChars, 4, 3, u8 );
PrintCountsAndBytes( myChars, 4, 3, u16LE );
PrintCountsAndBytes( myChars, 4, 3, u16BE );
PrintCountsAndBytes( myChars, 4, 3, u32 );
}
public static void PrintCountsAndBytes( char[] chars, int index, int count, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( chars, index, count );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( count );
Console.Write( " {0,-3} :", iMBC );
// Encode the array of chars.
byte[] bytes = enc.GetBytes( chars, index, count );
// The following is an alternative way to encode the array of chars:
// byte[] bytes = new byte[iBC];
// enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myChars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), ChrW(&H03B2), ChrW(&HD8FF), ChrW(&HDCFF) }
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode three characters starting at index 4, and print out the counts and the resulting bytes.
PrintCountsAndBytes(myChars, 4, 3, u7)
PrintCountsAndBytes(myChars, 4, 3, u8)
PrintCountsAndBytes(myChars, 4, 3, u16LE)
PrintCountsAndBytes(myChars, 4, 3, u16BE)
PrintCountsAndBytes(myChars, 4, 3, u32)
End Sub
Public Shared Sub PrintCountsAndBytes(chars() As Char, index As Integer, count As Integer, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(chars, index, count)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(count)
Console.Write(" {0,-3} :", iMBC)
' Encode the array of chars.
Dim bytes As Byte() = enc.GetBytes(chars, index, count)
' The following is an alternative way to encode the array of chars:
' NOTE: In VB.NET, arrays contain one extra element by default.
' The following line creates the array with the exact number of elements required.
' Dim bytes(iBC - 1) As Byte
' enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) )
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
'System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
Comentarios
Para calcular el tamaño exacto de la matriz necesario GetBytes para almacenar los bytes resultantes, debe llamar al GetByteCount método.To calculate the exact array size required by GetBytes to store the resulting bytes, you should call the GetByteCount method. Para calcular el tamaño máximo de la matriz, llame al GetMaxByteCount método.To calculate the maximum array size, call the GetMaxByteCount method. El GetByteCount método generalmente permite la asignación de menos memoria, mientras que el GetMaxByteCount método suele ejecutarse más rápido.The GetByteCount method generally allows allocation of less memory, while the GetMaxByteCount method generally executes faster.
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.
Consulte también
Se aplica a
GetBytes(String, Int32, Int32, Byte[], Int32)
Cuando se reemplaza en una clase derivada, codifica un juego de caracteres de la cadena especificada en la matriz de bytes especificada.When overridden in a derived class, encodes a set of characters from the specified string into the specified byte array.
public:
virtual int GetBytes(System::String ^ s, int charIndex, int charCount, cli::array <System::Byte> ^ bytes, int byteIndex);
public virtual int GetBytes (string s, int charIndex, int charCount, byte[] bytes, int byteIndex);
abstract member GetBytes : string * int * int * byte[] * int -> int
override this.GetBytes : string * int * int * byte[] * int -> int
Public Overridable Function GetBytes (s As String, charIndex As Integer, charCount As Integer, bytes As Byte(), byteIndex As Integer) As Integer
Parámetros
- s
- String
Cadena que contiene el juego de caracteres que se va a codificar.The string containing the set of characters to encode.
- charIndex
- Int32
Índice del primer carácter que se va a codificar.The index of the first character to encode.
- charCount
- Int32
Número de caracteres que se van a codificar.The number of characters to encode.
- bytes
- Byte[]
Matriz de bytes que contendrá la secuencia de bytes resultante.The byte array to contain the resulting sequence of bytes.
- byteIndex
- Int32
Índice en el que se inicia la escritura de la secuencia de bytes resultante.The index at which to start writing the resulting sequence of bytes.
Devoluciones
Número real de bytes escritos en bytes
.The actual number of bytes written into bytes
.
Excepciones
El valor de charIndex
, charCount
o byteIndex
es menor que cero.charIndex
or charCount
or byteIndex
is less than zero.
o bien-or-
charIndex
y charCount
no denotan un intervalo válido en chars
.charIndex
and charCount
do not denote a valid range in chars
.
o bien-or-
byteIndex
no es un índice válido para bytes
.byteIndex
is not a valid index in bytes
.
bytes
no tiene suficiente capacidad desde byteIndex
hasta el final de la matriz para alojar los bytes resultantes.bytes
does not have enough capacity from byteIndex
to the end of the array to accommodate the resulting bytes.
Se ha producido una reserva (para más información, vea Codificación de caracteres en .NET)A fallback occurred (for more information, see Character Encoding in .NET)
- y --and-
El valor de EncoderFallback está establecido en EncoderExceptionFallback.EncoderFallback is set to EncoderExceptionFallback.
Ejemplos
En el ejemplo siguiente se determina el número de bytes necesarios para codificar una cadena o un intervalo de la cadena, codifica los caracteres y muestra los bytes resultantes.The following example determines the number of bytes required to encode a string or a range in the string, encodes the characters, and displays the resulting bytes.
using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( String^ s, Encoding^ enc );
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String^ myStr = L"za\u0306\u01FD\u03B2\xD8FF\xDCFF";
// Get different encodings.
Encoding^ u7 = Encoding::UTF7;
Encoding^ u8 = Encoding::UTF8;
Encoding^ u16LE = Encoding::Unicode;
Encoding^ u16BE = Encoding::BigEndianUnicode;
Encoding^ u32 = Encoding::UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console::WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console::WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
void PrintCountsAndBytes( String^ s, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( s->Length );
Console::Write( " {0,-3} :", iMBC );
// Encode the entire string.
array<Byte>^bytes = enc->GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintCountsAndBytes( String^ s, int index, int count, Encoding^ enc )
{
// Display the name of the encoding used.
Console::Write( "{0,-30} :", enc );
// Display the exact byte count.
int iBC = enc->GetByteCount( s->ToCharArray(), index, count );
Console::Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc->GetMaxByteCount( count );
Console::Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
array<Byte>^bytes = gcnew array<Byte>(iBC);
enc->GetBytes( s, index, count, bytes, bytes->GetLowerBound( 0 ) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
void PrintHexBytes( array<Byte>^bytes )
{
if ( (bytes == nullptr) || (bytes->Length == 0) )
Console::WriteLine( "<none>" );
else
{
for ( int i = 0; i < bytes->Length; i++ )
Console::Write( "{0:X2} ", bytes[ i ] );
Console::WriteLine();
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
using System;
using System.Text;
public class SamplesEncoding {
public static void Main() {
// The characters to encode:
// Latin Small Letter Z (U+007A)
// Latin Small Letter A (U+0061)
// Combining Breve (U+0306)
// Latin Small Letter AE With Acute (U+01FD)
// Greek Small Letter Beta (U+03B2)
// a high-surrogate value (U+D8FF)
// a low-surrogate value (U+DCFF)
String myStr = "za\u0306\u01FD\u03B2\uD8FF\uDCFF";
// Get different encodings.
Encoding u7 = Encoding.UTF7;
Encoding u8 = Encoding.UTF8;
Encoding u16LE = Encoding.Unicode;
Encoding u16BE = Encoding.BigEndianUnicode;
Encoding u32 = Encoding.UTF32;
// Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the entire string:" );
PrintCountsAndBytes( myStr, u7 );
PrintCountsAndBytes( myStr, u8 );
PrintCountsAndBytes( myStr, u16LE );
PrintCountsAndBytes( myStr, u16BE );
PrintCountsAndBytes( myStr, u32 );
Console.WriteLine();
// Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine( "Encoding the characters from index 4 through 6:" );
PrintCountsAndBytes( myStr, 4, 3, u7 );
PrintCountsAndBytes( myStr, 4, 3, u8 );
PrintCountsAndBytes( myStr, 4, 3, u16LE );
PrintCountsAndBytes( myStr, 4, 3, u16BE );
PrintCountsAndBytes( myStr, 4, 3, u32 );
}
public static void PrintCountsAndBytes( String s, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( s.Length );
Console.Write( " {0,-3} :", iMBC );
// Encode the entire string.
byte[] bytes = enc.GetBytes( s );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintCountsAndBytes( String s, int index, int count, Encoding enc ) {
// Display the name of the encoding used.
Console.Write( "{0,-30} :", enc.ToString() );
// Display the exact byte count.
int iBC = enc.GetByteCount( s.ToCharArray(), index, count );
Console.Write( " {0,-3}", iBC );
// Display the maximum byte count.
int iMBC = enc.GetMaxByteCount( count );
Console.Write( " {0,-3} :", iMBC );
// Encode a range of characters in the string.
byte[] bytes = new byte[iBC];
enc.GetBytes( s, index, count, bytes, bytes.GetLowerBound(0) );
// Display all the encoded bytes.
PrintHexBytes( bytes );
}
public static void PrintHexBytes( byte[] bytes ) {
if (( bytes == null ) || ( bytes.Length == 0 ))
{
Console.WriteLine( "<none>" );
}
else {
for ( int i = 0; i < bytes.Length; i++ )
Console.Write( "{0:X2} ", bytes[i] );
Console.WriteLine();
}
}
}
/*
This code produces the following output.
Encoding the entire string:
System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
Encoding the characters from index 4 through 6:
System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
*/
Imports System.Text
Public Class SamplesEncoding
Public Shared Sub Main()
' The characters to encode:
' Latin Small Letter Z (U+007A)
' Latin Small Letter A (U+0061)
' Combining Breve (U+0306)
' Latin Small Letter AE With Acute (U+01FD)
' Greek Small Letter Beta (U+03B2)
' a high-surrogate value (U+D8FF)
' a low-surrogate value (U+DCFF)
Dim myStr As String = "za" & ChrW(&H0306) & ChrW(&H01FD) & ChrW(&H03B2) & ChrW(&HD8FF) & ChrW(&HDCFF)
' Get different encodings.
Dim u7 As Encoding = Encoding.UTF7
Dim u8 As Encoding = Encoding.UTF8
Dim u16LE As Encoding = Encoding.Unicode
Dim u16BE As Encoding = Encoding.BigEndianUnicode
Dim u32 As Encoding = Encoding.UTF32
' Encode the entire string, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the entire string:")
PrintCountsAndBytes(myStr, u7)
PrintCountsAndBytes(myStr, u8)
PrintCountsAndBytes(myStr, u16LE)
PrintCountsAndBytes(myStr, u16BE)
PrintCountsAndBytes(myStr, u32)
Console.WriteLine()
' Encode three characters starting at index 4, and print out the counts and the resulting bytes.
Console.WriteLine("Encoding the characters from index 4 through 6:")
PrintCountsAndBytes(myStr, 4, 3, u7)
PrintCountsAndBytes(myStr, 4, 3, u8)
PrintCountsAndBytes(myStr, 4, 3, u16LE)
PrintCountsAndBytes(myStr, 4, 3, u16BE)
PrintCountsAndBytes(myStr, 4, 3, u32)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(s.Length)
Console.Write(" {0,-3} :", iMBC)
' Encode the entire string.
Dim bytes As Byte() = enc.GetBytes(s)
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Overloads Public Shared Sub PrintCountsAndBytes(s As String, index As Integer, count As Integer, enc As Encoding)
' Display the name of the encoding used.
Console.Write("{0,-30} :", enc.ToString())
' Display the exact byte count.
Dim iBC As Integer = enc.GetByteCount(s.ToCharArray(), index, count)
Console.Write(" {0,-3}", iBC)
' Display the maximum byte count.
Dim iMBC As Integer = enc.GetMaxByteCount(count)
Console.Write(" {0,-3} :", iMBC)
' Encode a range of characters in the string.
' NOTE: In VB.NET, arrays contain one extra element by default.
' The following line creates the array with the exact number of elements required.
Dim bytes(iBC - 1) As Byte
enc.GetBytes(s, index, count, bytes, bytes.GetLowerBound(0))
' Display all the encoded bytes.
PrintHexBytes(bytes)
End Sub
Public Shared Sub PrintHexBytes(bytes() As Byte)
If bytes Is Nothing OrElse bytes.Length = 0 Then
Console.WriteLine("<none>")
Else
Dim i As Integer
For i = 0 To bytes.Length - 1
Console.Write("{0:X2} ", bytes(i))
Next i
Console.WriteLine()
End If
End Sub
End Class
'This code produces the following output.
'
'Encoding the entire string:
'System.Text.UTF7Encoding : 18 23 :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
'System.Text.UTF8Encoding : 12 24 :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 14 16 :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 14 16 :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 24 32 :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00
'
'Encoding the characters from index 4 through 6:
'System.Text.UTF7Encoding : 10 11 :2B 41 37 4C 59 2F 39 7A 2F 2D
'System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF
'System.Text.UTF32Encoding : 8 16 :B2 03 00 00 FF FC 04 00
Comentarios
Para calcular el tamaño exacto de la matriz necesario GetBytes para almacenar los bytes resultantes, debe llamar al GetByteCount método.To calculate the exact array size required by GetBytes to store the resulting bytes, you should call the GetByteCount method. Para calcular el tamaño máximo de la matriz, llame al GetMaxByteCount método.To calculate the maximum array size, call the GetMaxByteCount method. El GetByteCount método generalmente permite la asignación de menos memoria, mientras que el GetMaxByteCount método suele ejecutarse más rápido.The GetByteCount method generally allows allocation of less memory, while the GetMaxByteCount method generally executes faster.
Si los datos que se van a convertir solo están disponibles en bloques secuenciales (como los datos leídos de una secuencia) o si la cantidad de datos es tan grande que debe dividirse en bloques más pequeños, debe utilizar Decoder o Encoder proporcionado por el GetDecoder método o el GetEncoder método, respectivamente, de una clase derivada.If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, you should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
El GetByteCount método determina el número de bytes que dan como resultado la codificación de un conjunto de caracteres Unicode y el GetBytes método realiza la codificación real.The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. El Encoding.GetBytes método espera conversiones discretas, a diferencia del Encoder.GetBytes método, que controla varias conversiones en un solo flujo de entrada.The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.
GetByteCountSe admiten varias versiones de y GetBytes .Several versions of GetByteCount and GetBytes are supported. A continuación se indican algunas consideraciones de programación para el uso de estos métodos:The following are some programming considerations for use of these methods:
Es posible que la aplicación necesite codificar muchos caracteres de entrada en una página de códigos y procesar los caracteres mediante varias llamadas.Your app might need to encode many input characters to a code page and process the characters using multiple calls. En este caso, es probable que tenga que mantener el estado entre las llamadas, teniendo en cuenta el estado que conserva el Encoder objeto que se está usando.In this case, you probably need to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (Por ejemplo, una secuencia de caracteres que incluye pares suplentes puede acabar con un suplente alto.(For example, a character sequence that includes surrogate pairs might end with a high surrogate. EncoderRecordará ese suplente alto para que se pueda combinar con un suplente bajo al principio de una llamada siguiente.The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encodingno podrá mantener el estado, por lo que el carácter se enviará al EncoderFallback .)Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)
Si la aplicación controla entradas de cadena, debe usar la versión de cadena de GetBytes .If your app handles string inputs, you should use the string version of GetBytes.
La versión de búfer de caracteres Unicode de GetBytes(Char*, Int32, Byte*, Int32) permite algunas técnicas rápidas, especialmente con varias llamadas que usan el Encoder objeto o insertan en búferes existentes.The Unicode character buffer version of GetBytes(Char*, Int32, Byte*, Int32) allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Sin embargo, tenga en cuenta que esta versión del método no es segura a veces, ya que los punteros son necesarios.Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.
Si la aplicación debe convertir una gran cantidad de datos, debe volver a usar el búfer de salida.If your app must convert a large amount of data, it should reuse the output buffer. En este caso, la GetBytes versión que admite matrices de bytes es la mejor opción.In this case, the GetBytes version that supports byte arrays is the best choice.
Considere la posibilidad Encoder.Convert de usar el método en lugar de GetByteCount .Consider using the Encoder.Convert method instead of GetByteCount. El método de conversión convierte tantos datos como sea posible y produce una excepción si el búfer de salida es demasiado pequeño.The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. Para la codificación continua de una secuencia, este método suele ser la mejor opción.For continuous encoding of a stream, this method is often the best choice.