EncoderFallbackException Klasse

Definition

Die Ausnahme, die ausgelöst wird, wenn ein Fallbackvorgang fehlschlägt.The exception that is thrown when an encoder fallback operation fails. Diese Klasse kann nicht vererbt werden.This class cannot be inherited.

public ref class EncoderFallbackException sealed : ArgumentException
[System.Serializable]
public sealed class EncoderFallbackException : ArgumentException
type EncoderFallbackException = class
    inherit ArgumentException
Public NotInheritable Class EncoderFallbackException
Inherits ArgumentException
Vererbung
Attribute

Beispiele

Im folgenden Codebeispiel werden die EncoderExceptionFallback - EncoderFallbackException Klasse und die-Klasse veranschaulicht.The following code example demonstrates the EncoderExceptionFallback and EncoderFallbackException classes.

// This example demonstrates the EncoderExceptionFallback class.

using namespace System;
using namespace System::Text;

int main()
{
    // Create an encoding, which is equivalent to calling the
    // ASCIIEncoding class constructor.
    // The EncoderExceptionFallback parameter causes an exception to
    // be thrown when a character cannot be encoded.
    // A decoder exception fallback is also specified, but it is not
    // used because this example terminates during the encoding operation.

    Encoding^ asciiEncoding = Encoding::GetEncoding("us-ascii",
        gcnew EncoderExceptionFallback(), gcnew DecoderExceptionFallback());

    // The input string consists of the Unicode characters LEFT POINTING
    // DOUBLE ANGLE QUOTATION MARK (U+00AB), 'X' (U+0058), and RIGHT
    // POINTING DOUBLE ANGLE QUOTATION MARK (U+00BB).
    // The encoding can only encode characters in the US-ASCII range of
    // U+0000 through U+007F. Consequently, the characters bracketing the
    // 'X' character cause an exception.
    String^ inputString = L"\u00abX\u00bb";

    String^ twoNewLines = Environment::NewLine + Environment::NewLine;
    array<Byte>^ encodedBytes = gcnew array<Byte>(
        asciiEncoding->GetMaxByteCount(inputString->Length));
    int numberOfEncodedBytes = 0;

    // ---------------------------------------------------------------------
    Console::Clear();

    // Display the name of the encoding.
    Console::WriteLine("The name of the encoding is \"{0}\".{1}",
        asciiEncoding->WebName, Environment::NewLine);

    // Display the input string in text.
    Console::WriteLine("Input string ({0} characters): \"{1}\"",
        inputString->Length, inputString);

    // Display the input string in hexadecimal.
    Console::Write("Input string in hexadecimal: ");
    for each (char c in inputString)
    {
        Console::Write("0x{0:X2} ", c);
    }
    Console::Write(twoNewLines);

    // ---------------------------------------------------------------------
    // Attempt to encode the input string. However, an exception is thrown
    // before the input string can be encoded.

    Console::WriteLine("Encode the input string...");

    // The code example terminates during the call to the GetBytes() method.
    try
    {
        numberOfEncodedBytes = asciiEncoding->GetBytes(inputString, 0,
            inputString->Length, encodedBytes, 0);
        // This statement is never executed.
        Console::WriteLine("This statement is never executed.");
    }
    catch (EncoderFallbackException^ ex)
    {
        Console::WriteLine(ex);
        Console::WriteLine(
            "{0}*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***",
            Environment::NewLine);
    }
}

/*
This code example produces the following results:

The name of the encoding is "us-ascii".

Input string (3 characters): "X"
Input string in hexadecimal: 0xAB 0x58 0xBB

Encode the input string...
System.Text.EncoderFallbackException: Unable to translate Unicode character \u00AB at inde
x 0 to specified code page.
at System.Text.EncoderExceptionFallbackBuffer.Fallback(Char charUnknown, Int32 index)
at System.Text.EncoderFallbackBuffer.InternalFallback(Char ch, Char*& chars)
at System.Text.ASCIIEncoding.GetBytes(Char* chars, Int32 charCount, Byte* bytes, Int32
byteCount, EncoderNLS encoder)
at System.Text.ASCIIEncoding.GetBytes(String chars, Int32 charIndex, Int32 charCount, B
yte[] bytes, Int32 byteIndex)
at Sample.Main()

*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***

*/
// This example demonstrates the EncoderExceptionFallback class.

using System;
using System.Text;

class Sample 
{
    public static void Main() 
    {

// Create an encoding, which is equivalent to calling the 
// ASCIIEncoding class constructor. 
// The EncoderExceptionFallback parameter causes an exception to
// be thrown when a character cannot be encoded. 
// A decoder exception fallback is also specified, but it is not 
// used because this example terminates during the encoding operation.  

    Encoding ae = Encoding.GetEncoding(
                  "us-ascii",
                  new EncoderExceptionFallback(), 
                  new DecoderExceptionFallback());

// The input string consists of the Unicode characters LEFT POINTING 
// DOUBLE ANGLE QUOTATION MARK (U+00AB), 'X' (U+0058), and RIGHT POINTING 
// DOUBLE ANGLE QUOTATION MARK (U+00BB). 
// The encoding can only encode characters in the US-ASCII range of U+0000 
// through U+007F. Consequently, the characters bracketing the 'X' character
// cause an exception.
    string inputString = "\u00abX\u00bb";

    string twoNewLines = "\n\n";
    byte[] encodedBytes = new byte[ae.GetMaxByteCount(inputString.Length)];
    int numberOfEncodedBytes = 0;

// --------------------------------------------------------------------------
    Console.Clear();

// Display the name of the encoding.
    Console.WriteLine("The name of the encoding is \"{0}\".\n", ae.WebName);

// Display the input string in text.
    Console.WriteLine("Input string ({0} characters): \"{1}\"", 
                       inputString.Length, inputString);

// Display the input string in hexadecimal.
    Console.Write("Input string in hexadecimal: ");
    foreach (char c in inputString.ToCharArray()) {
        Console.Write("0x{0:X2} ", (int)c);}
    Console.Write(twoNewLines);

// --------------------------------------------------------------------------
// Attempt to encode the input string. However, an exception is thrown before
// the input string can be encoded.

    Console.WriteLine("Encode the input string...");

// The code example terminates during the call to the GetBytes() method.
    try {
        numberOfEncodedBytes = ae.GetBytes(inputString, 0, inputString.Length, 
                                           encodedBytes, 0);
        }
    catch (EncoderFallbackException e)
        {
        Console.WriteLine(e);
        Console.WriteLine("\n*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***");
        return;
        }

// This statement is never executed.
    Console.WriteLine("This statement is never executed.");
    }
}
/*
This code example produces the following results:

The name of the encoding is "us-ascii".

Input string (3 characters): "«X»"
Input string in hexadecimal: 0xAB 0x58 0xBB

Encode the input string...
System.Text.EncoderFallbackException: Unable to translate Unicode character \u00AB at inde
x 0 to specified code page.
   at System.Text.EncoderExceptionFallbackBuffer.Fallback(Char charUnknown, Int32 index)
   at System.Text.EncoderFallbackBuffer.InternalFallback(Char ch, Char*& chars)
   at System.Text.ASCIIEncoding.GetBytes(Char* chars, Int32 charCount, Byte* bytes, Int32
byteCount, EncoderNLS encoder)
   at System.Text.ASCIIEncoding.GetBytes(String chars, Int32 charIndex, Int32 charCount, B
yte[] bytes, Int32 byteIndex)
   at Sample.Main()

*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***

*/
' This example demonstrates the EncoderExceptionFallback class.
Imports System.Text

Class Sample
    Public Shared Sub Main() 
        
        ' Create an encoding, which is equivalent to calling the 
        ' ASCIIEncoding class constructor. 
        ' The EncoderExceptionFallback parameter causes an exception to
        ' be thrown when a character cannot be encoded. 
        ' A decoder exception fallback is also specified, but it is not 
        ' used because this example terminates during the encoding operation.  


        Dim eef As New EncoderExceptionFallback()
        Dim def As New DecoderExceptionFallback()
        Dim ae As Encoding = Encoding.GetEncoding("us-ascii", eef, def)
        
        ' The input string consists of the Unicode characters LEFT POINTING 
        ' DOUBLE ANGLE QUOTATION MARK (U+00AB), 'X' (U+0058), and RIGHT POINTING 
        ' DOUBLE ANGLE QUOTATION MARK (U+00BB). 
        ' The encoding can only encode characters in the US-ASCII range of U+0000 
        ' through U+007F. Consequently, the characters bracketing the 'X' character
        ' cause an exception.

        Dim inputString As String = "«X»"
        
        Dim twoNewLines As String = vbCrLf & vbCrLf
        Dim numberOfEncodedBytes As Integer = ae.GetMaxByteCount(inputString.Length)
        ' Counteract the compiler adding an extra element.
        Dim encodedBytes(numberOfEncodedBytes - 1) As Byte
        
        ' --------------------------------------------------------------------------
        Console.Clear()
        
        ' Display the name of the encoding.
        Console.WriteLine("The name of the encoding is ""{0}""." & vbCrLf, ae.WebName)
        
        ' Display the input string in text.
        Console.WriteLine("Input string ({0} characters): ""{1}""", _
                           inputString.Length, inputString)
        
        ' Display the input string in hexadecimal. 
        ' Each element is converted to an integer with Convert.ToInt32.
        Console.Write("Input string in hexadecimal: ")
        Dim c As Char
        For Each c In  inputString.ToCharArray()
            Console.Write("0x{0:X2} ", Convert.ToInt32(c))
        Next c
        Console.Write(twoNewLines)
        
        ' --------------------------------------------------------------------------
        ' Attempt to encode the input string. However, an exception is thrown before
        ' the input string can be encoded.
        Console.WriteLine("Encode the input string...")
        
        ' The code example terminates during the call to the GetBytes() method.
        Try
            numberOfEncodedBytes = ae.GetBytes(inputString, 0, inputString.Length, _
                                               encodedBytes, 0)
        Catch e As EncoderFallbackException
            Console.WriteLine(e)
            Console.WriteLine(vbCrLf & _
                              "*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***")
            Return
        End Try
        
        ' This statement is never executed.
        Console.WriteLine("This statement is never executed.")
    
    End Sub
End Class
'
'This code example produces the following results:
'
'The name of the encoding is "us-ascii".
'
'Input string (3 characters): "X"
'Input string in hexadecimal: 0xAB 0x58 0xBB
'
'Encode the input string...
'System.Text.EncoderFallbackException: Unable to translate Unicode character \u00AB at inde
'x 0 to specified code page.
'   at System.Text.EncoderExceptionFallbackBuffer.Fallback(Char charUnknown, Int32 index)
'   at System.Text.EncoderFallbackBuffer.InternalFallback(Char ch, Char*& chars)
'   at System.Text.ASCIIEncoding.GetBytes(Char* chars, Int32 charCount, Byte* bytes, Int32
'byteCount, EncoderNLS encoder)
'   at System.Text.ASCIIEncoding.GetBytes(String chars, Int32 charIndex, Int32 charCount, B
'yte[] bytes, Int32 byteIndex)
'   at Sample.Main()
'
'*** THE CODE EXAMPLE TERMINATES HERE AS INTENDED. ***
'

Konstruktoren

EncoderFallbackException()

Initialisiert eine neue Instanz der EncoderFallbackException-Klasse.Initializes a new instance of the EncoderFallbackException class.

EncoderFallbackException(String)

Initialisiert eine neue Instanz der EncoderFallbackException-Klasse.Initializes a new instance of the EncoderFallbackException class. Ein Parameter gibt die Fehlermeldung an.A parameter specifies the error message.

EncoderFallbackException(String, Exception)

Initialisiert eine neue Instanz der EncoderFallbackException-Klasse.Initializes a new instance of the EncoderFallbackException class. Parameter geben die Fehlermeldung und die innere Ausnahme an, die die Ausnahme verursacht hat.Parameters specify the error message and the inner exception that is the cause of this exception.

Eigenschaften

CharUnknown

Ruft das Eingabezeichen ab, das die Ausnahme verursacht hat.Gets the input character that caused the exception.

CharUnknownHigh

Ruft das hohe Komponentenzeichen des Ersatzzeichenpaars ab, das die Ausnahme verursacht hat.Gets the high component character of the surrogate pair that caused the exception.

CharUnknownLow

Ruft das niedrige Komponentenzeichen des Ersatzzeichenpaars ab, das die Ausnahme verursacht hat.Gets the low component character of the surrogate pair that caused the exception.

Data

Ruft eine Auflistung von Schlüssel-Wert-Paaren ab, die zusätzliche benutzerdefinierte Informationen über die Ausnahme bereitstellen.Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Geerbt von Exception)
HelpLink

Ruft einen Link zur Hilfedatei ab, die dieser Ausnahme zugeordnet ist, oder legt einen Link fest.Gets or sets a link to the help file associated with this exception.

(Geerbt von Exception)
HResult

Ruft HRESULT ab oder legt HRESULT fest. Dies ist ein codierter Wert, der einer bestimmten Ausnahme zugeordnet ist.Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Geerbt von Exception)
Index

Ruft die Indexposition im Eingabepuffer des Zeichens ab, das die Ausnahme verursacht hat.Gets the index position in the input buffer of the character that caused the exception.

InnerException

Ruft die Exception-Instanz ab, die die aktuelle Ausnahme verursacht hat.Gets the Exception instance that caused the current exception.

(Geerbt von Exception)
Message

Ruft die Fehlermeldung und den Parameternamen oder nur die Fehlermeldung ab, wenn kein Parametername festgelegt ist.Gets the error message and the parameter name, or only the error message if no parameter name is set.

(Geerbt von ArgumentException)
ParamName

Ruft den Namen des Parameters ab, der diese Ausnahme auslöst.Gets the name of the parameter that causes this exception.

(Geerbt von ArgumentException)
Source

Gibt den Namen der Anwendung oder des Objekts zurück, die bzw. das den Fehler verursacht hat, oder legt diesen fest.Gets or sets the name of the application or the object that causes the error.

(Geerbt von Exception)
StackTrace

Ruft eine Zeichenfolgendarstellung der unmittelbaren Frames in der Aufrufliste ab.Gets a string representation of the immediate frames on the call stack.

(Geerbt von Exception)
TargetSite

Ruft die Methode ab, die die aktuelle Ausnahme auslöst.Gets the method that throws the current exception.

(Geerbt von Exception)

Methoden

Equals(Object)

Ermittelt, ob das angegebene Objekt und das aktuelle Objekt gleich sind.Determines whether the specified object is equal to the current object.

(Geerbt von Object)
GetBaseException()

Gibt beim Überschreiben in einer abgeleiteten Klasse eine Exception zurück, die die ursprüngliche Ursache für eine oder mehrere nachfolgende Ausnahmen ist.When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Geerbt von Exception)
GetHashCode()

Dient als die Standard-HashfunktionServes as the default hash function.

(Geerbt von Object)
GetObjectData(SerializationInfo, StreamingContext)

Legt das SerializationInfo-Objekt mit dem Parameternamen und zusätzlichen Informationen zur Ausnahme fest.Sets the SerializationInfo object with the parameter name and additional exception information.

(Geerbt von ArgumentException)
GetType()

Ruft den Laufzeittyp der aktuellen Instanz ab.Gets the runtime type of the current instance.

(Geerbt von Exception)
IsUnknownSurrogate()

Gibt an, ob die Eingabe, die die Ausnahme verursacht hat, ein Ersatzzeichenpaar ist.Indicates whether the input that caused the exception is a surrogate pair.

MemberwiseClone()

Erstellt eine flache Kopie des aktuellen Object.Creates a shallow copy of the current Object.

(Geerbt von Object)
ToString()

Erstellt eine Zeichenfolgendarstellung der aktuellen Ausnahme und gibt diese zurück.Creates and returns a string representation of the current exception.

(Geerbt von Exception)

Ereignisse

SerializeObjectState

Tritt auf, wenn eine Ausnahme serialisiert wird, um ein Ausnahmezustandsobjekt mit serialisierten Daten über die Ausnahme zu erstellen.Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(Geerbt von Exception)

Gilt für:

Siehe auch