Encoder.GetByteCount Method

Definition

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters.

Overloads

GetByteCount(ReadOnlySpan<Char>, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters in the 'chars' span. A parameter indicates whether to clear the internal state of the encoder after the calculation.

GetByteCount(Char*, Int32, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters starting at the specified character pointer. A parameter indicates whether to clear the internal state of the encoder after the calculation.

GetByteCount(Char[], Int32, Int32, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters from the specified character array. A parameter indicates whether to clear the internal state of the encoder after the calculation.

Remarks

This method does not affect the state of the encoder.

To calculate the exact array size that GetBytes requires to store the resulting bytes, the application should use GetByteCount.

If GetBytes is called with flush set to false, the encoder stores trailing characters at the end of the data block in an internal buffer and uses them in the next encoding operation. The application should call GetByteCount on a block of data immediately before calling GetBytes on the same block, so that any trailing characters from the previous block are included in the calculation.

GetByteCount(ReadOnlySpan<Char>, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters in the 'chars' span. A parameter indicates whether to clear the internal state of the encoder after the calculation.

public:
 virtual int GetByteCount(ReadOnlySpan<char> chars, bool flush);
public virtual int GetByteCount (ReadOnlySpan<char> chars, bool flush);
abstract member GetByteCount : ReadOnlySpan<char> * bool -> int
override this.GetByteCount : ReadOnlySpan<char> * bool -> int
Public Overridable Function GetByteCount (chars As ReadOnlySpan(Of Char), flush As Boolean) As Integer

Parameters

chars
ReadOnlySpan<Char>

A character span to encode.

flush
Boolean

true to simulate clearing the internal state of the encoder after the calculation; otherwise, false.

Returns

The number of bytes produced by encoding the specified characters and any characters in the internal buffer.

GetByteCount(Char*, Int32, Boolean)

Important

This API is not CLS-compliant.

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters starting at the specified character pointer. A parameter indicates whether to clear the internal state of the encoder after the calculation.

public:
 virtual int GetByteCount(char* chars, int count, bool flush);
[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(false)]
[System.Security.SecurityCritical]
public virtual int GetByteCount (char* chars, int count, bool flush);
abstract member GetByteCount : nativeptr<char> * int * bool -> int
override this.GetByteCount : nativeptr<char> * int * bool -> int

Parameters

chars
Char*

A pointer to the first character to encode.

count
Int32

The number of characters to encode.

flush
Boolean

true to simulate clearing the internal state of the encoder after the calculation; otherwise, false.

Returns

The number of bytes produced by encoding the specified characters and any characters in the internal buffer.

Attributes

Exceptions

chars is null (Nothing in Visual Basic .NET).

count is less than zero.

A fallback occurred (see Character Encoding in the .NET Framework for fuller explanation)

-and-

Fallback is set to EncoderExceptionFallback.

Security

SecurityCriticalAttribute
Requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

See also

GetByteCount(Char[], Int32, Int32, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters from the specified character array. A parameter indicates whether to clear the internal state of the encoder after the calculation.

public:
 abstract int GetByteCount(cli::array <char> ^ chars, int index, int count, bool flush);
public abstract int GetByteCount (char[] chars, int index, int count, bool flush);
abstract member GetByteCount : char[] * int * int * bool -> int
Public MustOverride Function GetByteCount (chars As Char(), index As Integer, count As Integer, flush As Boolean) As Integer

Parameters

chars
Char[]

The character array containing the set of characters to encode.

index
Int32

The index of the first character to encode.

count
Int32

The number of characters to encode.

flush
Boolean

true to simulate clearing the internal state of the encoder after the calculation; otherwise, false.

Returns

The number of bytes produced by encoding the specified characters and any characters in the internal buffer.

Exceptions

chars is null.

index or count is less than zero.

-or-

index and count do not denote a valid range in chars.

A fallback occurred (see Character Encoding in the .NET Framework for fuller explanation)

-and-

Fallback is set to EncoderExceptionFallback.

Examples

The following code example demonstrates how to use the GetByteCount method to return the number of bytes required to encode an array of characters using a Unicode Encoder.

using namespace System;
using namespace System::Text;
int main()
{
   
   // Unicode characters.
   
   // Pi
   // Sigma
   array<Char>^chars = {L'\u03a0',L'\u03a3',L'\u03a6',L'\u03a9'};
   Encoder^ uniEncoder = Encoding::Unicode->GetEncoder();
   int byteCount = uniEncoder->GetByteCount( chars, 0, chars->Length, true );
   Console::WriteLine( "{0} bytes needed to encode characters.", byteCount );
}

/* This code example produces the following output. 

8 bytes needed to encode characters.

*/

using System;
using System.Text;

class EncoderExample {
    public static void Main() {
        // Unicode characters.
        Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        };

        Encoder uniEncoder = Encoding.Unicode.GetEncoder();
        int byteCount = uniEncoder.GetByteCount(chars, 0, chars.Length, true);
        Console.WriteLine(
            "{0} bytes needed to encode characters.", byteCount
        );
    }
}

/* This example produces the following output.

8 bytes needed to encode characters.

*/
Imports System.Text
Imports Microsoft.VisualBasic.Strings

Class EncoderExample
    
    Public Shared Sub Main()
        ' Unicode characters.
        ' ChrW(35)  = #
        ' ChrW(37)  = %
        ' ChrW(928) = Pi
        ' ChrW(931) = Sigma
        Dim chars() As Char = {ChrW(35), ChrW(37), ChrW(928), ChrW(931)}
        
        Dim uniEncoder As Encoder = Encoding.Unicode.GetEncoder()
        Dim byteCount As Integer = _
            uniEncoder.GetByteCount(chars, 0, chars.Length, True)
        Console.WriteLine("{0} bytes needed to encode characters.", byteCount)
    End Sub
End Class
'
'This example produces the following output.
'
'8 bytes needed to encode characters.
'

See also

Applies to