Encoding.ASCII 属性
获取 ASCII（7 位）字符集的编码。
**命名空间:**System.Text
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
Public Shared ReadOnly Property ASCII As Encoding
用法
Dim value As Encoding
value = Encoding.ASCII
public static Encoding ASCII { get; }
public:
static property Encoding^ ASCII {
Encoding^ get ();
}
/** @property */
public static Encoding get_ASCII ()
public static function get ASCII () : Encoding
属性值
ASCII（7 位）字符集的 Encoding。
备注
ASCII 字符限于最低 128 个 Unicode 字符（从 U+0000 到 U+007F）。
示例
下面的代码示例演示了 ASCII 范围之外的字符的 ASCII 编码效果。
Imports System
Imports System.Text
Imports Microsoft.VisualBasic
Namespace Encoding_Examples
Class EncodingExample
Public Shared Sub Main()
' Create and ASCII encoding.
Dim ascii As Encoding = Encoding.ASCII
' A Unicode string with two characters outside the ASCII code range.
Dim unicodeString As [String] = "This unicode string contains two characters " + "with codes outside the ASCII code range, " + "Pi (" & ChrW(&H03A0) & ") and Sigma (" & ChrW(&H03A3) & ")."
Console.WriteLine("Original string:")
Console.WriteLine(unicodeString)
' Save the positions of the special characters for later reference.
Dim indexOfPi As Integer = unicodeString.IndexOf(ChrW(&H03A0))
Dim indexOfSigma As Integer = unicodeString.IndexOf(ChrW(&H03A3))
' Encode the string.
Dim encodedBytes As [Byte]() = ascii.GetBytes(unicodeString)
Console.WriteLine()
Console.WriteLine("Encoded bytes:")
Dim b As [Byte]
For Each b In encodedBytes
Console.Write("[{0}]", b)
Next b
Console.WriteLine()
' Notice that the special characters have been replaced with
' the value 63, which is the ASCII character code for '?'.
Console.WriteLine()
Console.WriteLine("Value at position of Pi character: {0}", encodedBytes(indexOfPi))
Console.WriteLine("Value at position of Sigma character: {0}", encodedBytes(indexOfSigma))
' Decode bytes back to a string.
' Notice missing Pi and Sigma characters.
Dim decodedString As [String] = ascii.GetString(encodedBytes)
Console.WriteLine()
Console.WriteLine("Decoded bytes:")
Console.WriteLine(decodedString)
End Sub
End Class
End Namespace
using System;
using System.Text;
namespace Encoding_Examples
{
using System;
using System.Text;
class EncodingExample
{
public static void Main()
{
// Create an ASCII encoding.
Encoding ascii = Encoding.ASCII;
// A Unicode string with two characters outside the ASCII code range.
String unicodeString =
"This unicode string contains two characters " +
"with codes outside the ASCII code range, " +
"Pi (\u03a0) and Sigma (\u03a3).";
Console.WriteLine("Original string:");
Console.WriteLine(unicodeString);
// Save the positions of the special characters for later reference.
int indexOfPi = unicodeString.IndexOf('\u03a0');
int indexOfSigma = unicodeString.IndexOf('\u03a3');
// Encode the string.
Byte[] encodedBytes = ascii.GetBytes(unicodeString);
Console.WriteLine();
Console.WriteLine("Encoded bytes:");
foreach (Byte b in encodedBytes)
{
Console.Write("[{0}]", b);
}
Console.WriteLine();
// Notice that the special characters have been replaced with
// the value 63, which is the ASCII character code for '?'.
Console.WriteLine();
Console.WriteLine(
"Value at position of Pi character: {0}",
encodedBytes[indexOfPi]
);
Console.WriteLine(
"Value at position of Sigma character: {0}",
encodedBytes[indexOfSigma]
);
// Decode bytes back to a string.
// Notice missing the Pi and Sigma characters.
String decodedString = ascii.GetString(encodedBytes);
Console.WriteLine();
Console.WriteLine("Decoded bytes:");
Console.WriteLine(decodedString);
}
}
}
using namespace System;
using namespace System::Text;
using namespace System::Collections;
int main()
{
// Create an ASCII encoding.
Encoding^ ascii = Encoding::ASCII;
// A Unicode String* with two characters outside the ASCII code range.
String^ unicodeString = L"This unicode string contains two characters with codes outside the ASCII code range, Pi (\u03a0) and Sigma (\u03a3).";
Console::WriteLine( "Original string:" );
Console::WriteLine( unicodeString );
// Save the positions of the special characters for later reference.
int indexOfPi = unicodeString->IndexOf( L'\u03a0' );
int indexOfSigma = unicodeString->IndexOf( L'\u03a3' );
// Encode the String*.
array<Byte>^encodedBytes = ascii->GetBytes( unicodeString );
Console::WriteLine();
Console::WriteLine( "Encoded bytes:" );
IEnumerator^ myEnum = encodedBytes->GetEnumerator();
while ( myEnum->MoveNext() )
{
Byte b = safe_cast<Byte>(myEnum->Current);
Console::Write( "[{0}]", b );
}
Console::WriteLine();
// Notice that the special characters have been replaced with
// the value 63, which is the ASCII character code for '?'.
Console::WriteLine();
Console::WriteLine( "Value at position of Pi character: {0}", encodedBytes[ indexOfPi ] );
Console::WriteLine( "Value at position of Sigma character: {0}", encodedBytes[ indexOfSigma ] );
// Decode bytes back to String*.
// Notice the missing Pi and Sigma characters.
String^ decodedString = ascii->GetString( encodedBytes );
Console::WriteLine();
Console::WriteLine( "Decoded bytes:" );
Console::WriteLine( decodedString );
}
package Encoding_Examples ;
import System.* ;
import System.Text.* ;
import System.Byte;
class EncodingExample
{
public static void main(String[] args)
{
// Create an ASCII encoding.
Encoding ascii = Encoding.get_ASCII();
// A Unicode string with two characters outside the ASCII code range.
String unicodeString = "This unicode string contains two characters "
+ "with codes outside the ASCII code range, "
+ "Pi (\u03a0) and Sigma (\u03a3).";
Console.WriteLine("Original string:");
Console.WriteLine(unicodeString);
// Save the positions of the special characters for later reference.
int indexOfPi = unicodeString.IndexOf('\u03a0');
int indexOfSigma = unicodeString.IndexOf('\u03a0');
// Encode the string.
Byte encodedBytes[] = (Byte[])ascii.GetBytes(unicodeString);
Console.WriteLine();
Console.WriteLine("Encoded bytes:");
for (int i = 0; i < encodedBytes.length; i++) {
Byte b = encodedBytes[i];
Console.Write("[{0}]", b);
}
Console.WriteLine();
// Notice that the special characters have been replaced with
// the value 63, which is the ASCII character code for '?'.
Console.WriteLine();
Console.WriteLine("Value at position of Pi character: {0}",
encodedBytes.get_Item(indexOfPi));
Console.WriteLine("Value at position of Sigma character: {0}",
encodedBytes.get_Item(indexOfSigma));
// Decode bytes back to a string.
// Notice missing the Pi and Sigma characters.
String decodedString = ascii.GetString((ubyte[])encodedBytes);
Console.WriteLine();
Console.WriteLine("Decoded bytes:");
Console.WriteLine(decodedString);
}
}
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
.NET Compact Framework
受以下版本支持：2.0、1.0
请参见
参考
Encoding 类
Encoding 成员
System.Text 命名空间
ASCIIEncoding 类
GetEncoding
Default
UTF7
UTF8
Unicode
BigEndianUnicode
UTF32