UTF7Encoding.GetEncoder 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
取得可以將 Unicode 字元序列轉換成以 UTF-7 編碼的位元組序列的編碼器。
public:
override System::Text::Encoder ^ GetEncoder();
public override System.Text.Encoder GetEncoder ();
override this.GetEncoder : unit -> System.Text.Encoder
Public Overrides Function GetEncoder () As Encoder
傳回
Encoder,可以將 Unicode 字元序列轉換成以 UTF-7 編碼的位元組序列。
範例
下列程式碼範例示範如何使用 GetEncoder 方法來取得編碼器,將字元序列轉換成 UTF-7 編碼的位元組序列。
using namespace System;
using namespace System::Text;
using namespace System::Collections;
int main()
{
array<Char>^chars = {'a','b','c',L'\u0300',L'\ua0a0'};
array<Byte>^bytes;
Encoder^ utf7Encoder = Encoding::UTF7->GetEncoder();
int byteCount = utf7Encoder->GetByteCount( chars, 2, 3, true );
bytes = gcnew array<Byte>(byteCount);
int bytesEncodedCount = utf7Encoder->GetBytes( chars, 2, 3, bytes, 0, true );
Console::WriteLine( "{0} bytes used to encode characters.", bytesEncodedCount );
Console::Write( "Encoded bytes: " );
IEnumerator^ myEnum = bytes->GetEnumerator();
while ( myEnum->MoveNext() )
{
Byte b = safe_cast<Byte>(myEnum->Current);
Console::Write( "[{0}]", b );
}
Console::WriteLine();
}
using System;
using System.Text;
class UTF7EncodingExample {
public static void Main() {
Char[] chars = new Char[] {'a', 'b', 'c', '\u0300', '\ua0a0'};
Byte[] bytes;
Encoder utf7Encoder = Encoding.UTF7.GetEncoder();
int byteCount = utf7Encoder.GetByteCount(chars, 2, 3, true);
bytes = new Byte[byteCount];
int bytesEncodedCount = utf7Encoder.GetBytes(chars, 2, 3, bytes, 0, true);
Console.WriteLine(
"{0} bytes used to encode characters.", bytesEncodedCount
);
Console.Write("Encoded bytes: ");
foreach (Byte b in bytes) {
Console.Write("[{0}]", b);
}
Console.WriteLine();
}
}
Imports System.Text
Imports Microsoft.VisualBasic.Strings
Class UTF7EncodingExample
Public Shared Sub Main()
'Characters:
' ChrW(97) = a
' ChrW(98) = b
' ChrW(99) = c
' ChrW(768) = `
' ChrW(41120) = valid unicode code point, but not a character
Dim chars() As Char = {ChrW(97), ChrW(98), ChrW(99), ChrW(768), ChrW(41120)}
Dim bytes() As Byte
Dim utf7Encoder As Encoder = Encoding.UTF7.GetEncoder()
Dim byteCount As Integer = utf7Encoder.GetByteCount(chars, 2, 3, True)
bytes = New Byte(byteCount - 1) {}
Dim bytesEncodedCount As Integer = utf7Encoder.GetBytes(chars, 2, 3, bytes, 0, True)
Console.WriteLine("{0} bytes used to encode characters.", bytesEncodedCount)
Console.Write("Encoded bytes: ")
Dim b As Byte
For Each b In bytes
Console.Write("[{0}]", b)
Next b
Console.WriteLine()
End Sub
End Class
備註
方法 Decoder.GetChars 會以類似 GetChars 方法的方式,將位元組的循序區塊轉換成字元的循序區塊。 不過,會 Decoder 維護 呼叫之間的狀態資訊,以便正確地解碼跨越區塊的位元組序列。 Decoder也會在資料區塊結尾保留尾端的位元組,並在下一個解碼作業中使用尾端位元組。 因此, GetDecoder 和 GetEncoder 對於網路傳輸和檔案作業很有用,因為這些作業通常會處理資料區塊,而不是完整的資料流程。