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EncoderFallbackException Class

The exception that is thrown when an encoder fallback operation fails. This class cannot be inherited.

System.Object
  System.Exception
    System.SystemException
      System.ArgumentException
        System.Text.EncoderFallbackException

Namespace:  System.Text
Assembly:  mscorlib (in mscorlib.dll)

[SerializableAttribute]
public sealed class EncoderFallbackException : ArgumentException

The EncoderFallbackException type exposes the following members.

  NameDescription
Public methodSupported by Portable Class LibraryEncoderFallbackException()Initializes a new instance of the EncoderFallbackException class.
Public methodSupported by Portable Class LibraryEncoderFallbackException(String)Initializes a new instance of the EncoderFallbackException class. A parameter specifies the error message.
Public methodSupported by Portable Class LibraryEncoderFallbackException(String, Exception)Initializes a new instance of the EncoderFallbackException class. Parameters specify the error message and the inner exception that is the cause of this exception.
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  NameDescription
Public propertySupported by Portable Class LibraryCharUnknownGets the input character that caused the exception.
Public propertySupported by Portable Class LibraryCharUnknownHighGets the high component character of the surrogate pair that caused the exception.
Public propertySupported by Portable Class LibraryCharUnknownLowGets the low component character of the surrogate pair that caused the exception.
Public propertyDataGets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception.)
Public propertyHelpLinkGets or sets a link to the help file associated with this exception. (Inherited from Exception.)
Protected propertySupported by Portable Class LibraryHResultGets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception.)
Public propertySupported by Portable Class LibraryIndexGets the index position in the input buffer of the character that caused the exception.
Public propertySupported by Portable Class LibraryInnerExceptionGets the Exception instance that caused the current exception. (Inherited from Exception.)
Public propertyMessageGets the error message and the parameter name, or only the error message if no parameter name is set. (Inherited from ArgumentException.)
Public propertyParamNameGets the name of the parameter that causes this exception. (Inherited from ArgumentException.)
Public propertySourceGets or sets the name of the application or the object that causes the error. (Inherited from Exception.)
Public propertySupported by Portable Class LibraryStackTraceGets a string representation of the immediate frames on the call stack. (Inherited from Exception.)
Public propertyTargetSiteGets the method that throws the current exception. (Inherited from Exception.)
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  NameDescription
Public methodSupported by Portable Class LibraryEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Portable Class LibraryFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Portable Class LibraryGetBaseExceptionWhen overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception.)
Public methodSupported by Portable Class LibraryGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetObjectDataSets the SerializationInfo object with the parameter name and additional exception information. (Inherited from ArgumentException.)
Public methodGetTypeGets the runtime type of the current instance. (Inherited from Exception.)
Public methodIsUnknownSurrogateIndicates whether the input that caused the exception is a surrogate pair.
Protected methodSupported by Portable Class LibraryMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Portable Class LibraryToStringCreates and returns a string representation of the current exception. (Inherited from Exception.)
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  NameDescription
Protected eventSerializeObjectStateOccurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception.)
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The following code example demonstrates the EncoderExceptionFallback and EncoderFallbackException classes.


// 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. ***

*/


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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