EncoderFallbackException 类
定义
重要
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编码器回退操作失败时引发的异常。 此类不能被继承。
public ref class EncoderFallbackException sealed : ArgumentExceptionpublic sealed class EncoderFallbackException : ArgumentException[System.Serializable]
public sealed class EncoderFallbackException : ArgumentExceptiontype EncoderFallbackException = class
inherit ArgumentException[<System.Serializable>]
type EncoderFallbackException = class
inherit ArgumentExceptionPublic NotInheritable Class EncoderFallbackException
Inherits ArgumentException- 继承
- 继承
- 属性
示例
下面的代码示例演示 和 EncoderExceptionFallbackEncoderFallbackException 类。
// 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. ***
'
构造函数
| EncoderFallbackException() |
初始化 EncoderFallbackException 类的新实例。 |
| EncoderFallbackException(String) |
初始化 EncoderFallbackException 类的新实例。 一个参数指定错误信息。 |
| EncoderFallbackException(String, Exception) |
初始化 EncoderFallbackException 类的新实例。 参数指定错误信息和导致此异常的内部异常。 |
属性
| CharUnknown |
获取导致异常的输入字符。 |
| CharUnknownHigh |
获取导致异常的代理项对的高组件字符。 |
| CharUnknownLow |
获取导致异常的代理项对的低组件字符。 |
| Data |
获取键/值对的集合，这些键/值对提供有关该异常的其他用户定义信息。 (继承自 Exception) |
| HelpLink |
获取或设置指向与此异常关联的帮助文件链接。 (继承自 Exception) |
| HResult |
获取或设置 HRESULT（一个分配给特定异常的编码数字值）。 (继承自 Exception) |
| Index |
获取导致异常的字符在输入缓冲区中的索引位置。 |
| InnerException |
获取导致当前异常的 Exception 实例。 (继承自 Exception) |
| Message |
获取错误消息和参数名；如果未设置参数名，则仅获取错误消息。 (继承自 ArgumentException) |
| ParamName |
获取导致该异常的参数的名称。 (继承自 ArgumentException) |
| Source |
获取或设置导致错误的应用程序或对象的名称。 (继承自 Exception) |
| StackTrace |
获取调用堆栈上的即时框架字符串表示形式。 (继承自 Exception) |
| TargetSite |
获取引发当前异常的方法。 (继承自 Exception) |
方法
| Equals(Object) |
确定指定对象是否等于当前对象。 (继承自 Object) |
| GetBaseException() |
当在派生类中重写时，返回 Exception，它是一个或多个并发的异常的根本原因。 (继承自 Exception) |
| GetHashCode() |
作为默认哈希函数。 (继承自 Object) |
| GetObjectData(SerializationInfo, StreamingContext) |
设置带有参数名和附加异常信息的 SerializationInfo 对象。 (继承自 ArgumentException) |
| GetType() |
获取当前实例的运行时类型。 (继承自 Exception) |
| IsUnknownSurrogate() |
指示导致异常的输入是否为代理项对。 |
| MemberwiseClone() |
创建当前 Object 的浅表副本。 (继承自 Object) |
| ToString() |
创建并返回当前异常的字符串表示形式。 (继承自 Exception) |
事件
| SerializeObjectState |
已过时.
当异常被序列化用来创建包含有关该异常的徐列出数据的异常状态对象时会出现该问题。 (继承自 Exception) |