Encoding.ASCII プロパティ

.NET Framework クラス ライブラリ リファレンス

Encoding.ASCII プロパティ

ASCII (7 ビット) 文字セットのエンコーディングを取得します。

名前空間: System.Text
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Shared ReadOnly Property
 ASCII As Encoding

Visual Basic (使用法)

Dim value As Encoding

value = Encoding.ASCII

C#

public static Encoding ASCII { get;
 }

C++

public:
static property Encoding^ ASCII {
    Encoding^ get ();
}

J#

/** @property */
public static Encoding get_ASCII ()

JScript

public static function get
 ASCII () : Encoding

プロパティ値
ASCII (7 ビット) 文字セットの Encoding。

解説

ASCII 文字は、最初の 128 個の Unicode 文字 (U+0000 から U+007F) に限定されます。

使用例

次のコード例は、ASCII の範囲外の文字を ASCII エンコーディングすることによる影響を示しています。

Visual Basic

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

C#

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);
        }
    }
}

C++

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 );
}

J#

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);
    }
}

プラットフォーム

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

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0
.NET Compact Framework
サポート対象 : 2.0、1.0

参照

関連項目
Encoding クラス
Encoding メンバ
System.Text 名前空間
ASCIIEncoding クラス
GetEncoding
Default
UTF7
UTF8
Unicode
BigEndianUnicode
UTF32