本文整理汇总了VB.NET中System.Text.EncoderExceptionFallback类的典型用法代码示例。如果您正苦于以下问题：VB.NET EncoderExceptionFallback类的具体用法？VB.NET EncoderExceptionFallback怎么用？VB.NET EncoderExceptionFallback使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了EncoderExceptionFallback类的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: Sample
' 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输出：
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. ***