UTF7Encoding 类

定义

public ref class UTF7Encoding : System::Text::Encoding

public class UTF7Encoding : System.Text.Encoding

[System.Serializable]
public class UTF7Encoding : System.Text.Encoding

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class UTF7Encoding : System.Text.Encoding

type UTF7Encoding = class
    inherit Encoding

[<System.Serializable>]
type UTF7Encoding = class
    inherit Encoding

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type UTF7Encoding = class
    inherit Encoding

Public Class UTF7Encoding
Inherits Encoding

继承

Object

Encoding

UTF7Encoding

属性

SerializableAttribute ComVisibleAttribute

示例

下面的代码示例演示如何使用 a a UTF7Encoding 编码 Unicode 字符字符串并将其存储在字节数组中。 请注意，当字节数组解码回字符串时，不会丢失任何数据。

using System;
using System.Text;

class UTF7EncodingExample {
    public static void Main() {
        // Create a UTF-7 encoding.
        UTF7Encoding utf7 = new UTF7Encoding();
        
        // A Unicode string with two characters outside a 7-bit code range.
        String unicodeString =
            "This Unicode string contains two characters " +
            "with codes outside a 7-bit code range, " +
            "Pi (\u03a0) and Sigma (\u03a3).";
        Console.WriteLine("Original string:");
        Console.WriteLine(unicodeString);

        // Encode the string.
        Byte[] encodedBytes = utf7.GetBytes(unicodeString);
        Console.WriteLine();
        Console.WriteLine("Encoded bytes:");
        foreach (Byte b in encodedBytes) {
            Console.Write("[{0}]", b);
        }
        Console.WriteLine();
        
        // Decode bytes back to string.
        // Notice Pi and Sigma characters are still present.
        String decodedString = utf7.GetString(encodedBytes);
        Console.WriteLine();
        Console.WriteLine("Decoded bytes:");
        Console.WriteLine(decodedString);
    }
}

Imports System.Text
Imports Microsoft.VisualBasic.Strings

Class UTF7EncodingExample
    
    Public Shared Sub Main()
        ' Create a UTF-7 encoding.
        Dim utf7 As New UTF7Encoding()
        
        ' A Unicode string with two characters outside a 7-bit code range.
        Dim unicodeString As String = _
            "This Unicode string contains two characters " & _
            "with codes outside a 7-bit code range, " & _
            "Pi (" & ChrW(928) & ") and Sigma (" & ChrW(931) & ")."
        Console.WriteLine("Original string:")
        Console.WriteLine(unicodeString)
        
        ' Encode the string.
        Dim encodedBytes As Byte() = utf7.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()
        
        ' Decode bytes back to string.
        ' Notice Pi and Sigma characters are still present.
        Dim decodedString As String = utf7.GetString(encodedBytes)
        Console.WriteLine()
        Console.WriteLine("Decoded bytes:")
        Console.WriteLine(decodedString)
    End Sub
End Class

注解

编码是将一组 Unicode 字符转换为字节序列的过程。 解码是将编码字节序列转换为一组 Unicode 字符的过程。

UTF-7 编码将 Unicode 字符表示为 7 位 ASCII 字符序列。 此编码支持需要某些协议，通常是电子邮件或新闻组协议。 由于 UTF-7 不是特别安全或可靠的，并且大多数新式系统允许 8 位编码，因此 UTF-8 通常应优先于 UTF-7。

有关 UTF 和支持的其他编码 System.Text的详细信息，请参阅 .NET Framework 中的字符编码。

该方法 GetByteCount 确定对一组 Unicode 字符进行编码的字节数，该方法 GetBytes 执行实际编码。

同样，该方法 GetCharCount 确定对字节序列进行解码的字符数，以及 GetChars 执行 GetString 实际解码的方法。

UTF7Encoding对应于Windows代码页 65000。

另请参阅

• Decoder
• Encoder
• 了解编码