Encoder.Convert 方法

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

public:
 virtual void Convert(ReadOnlySpan<char> chars, Span<System::Byte> bytes, bool flush, [Runtime::InteropServices::Out] int % charsUsed, [Runtime::InteropServices::Out] int % bytesUsed, [Runtime::InteropServices::Out] bool % completed);

public virtual void Convert(ReadOnlySpan<char> chars, Span<byte> bytes, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

abstract member Convert : ReadOnlySpan<char> * Span<byte> * bool * int * int * bool -> unit
override this.Convert : ReadOnlySpan<char> * Span<byte> * bool * int * int * bool -> unit

Public Overridable Sub Convert (chars As ReadOnlySpan(Of Char), bytes As Span(Of Byte), flush As Boolean, ByRef charsUsed As Integer, ByRef bytesUsed As Integer, ByRef completed As Boolean)

参数

注解

请记住，对象 Encoder 在调用 Convert之间保存状态。 当应用程序使用数据流完成时，它应设置 flush 参数以确保 true 刷新状态信息。 使用此设置，编码器会忽略数据块末尾的无效字节并清除内部缓冲区。 作为逻辑单元的一部分（例如代理项对的高代理项）的任何剩余已处理数据都会根据当前的回退设置进行转换。

该方法 Convert 设计为在循环中使用，以编码任意数量的输入，例如从文件或流中读取的数据。 它将编码操作的输出存储在固定大小的缓冲区中。 GetBytes 如果输出缓冲区不够大，但 Convert 会尽可能填充空间并返回写入的字符读取和字节，将引发异常。 另请参阅主题 Encoding.GetBytes 以获取更多注释。

completed输出参数指示输入缓冲区中的所有数据是否已转换并存储在输出缓冲区中。 如果无法转换参数指定的字符数，且不能超过参数指定的字节数，则此参数设置为 < a0/>。 在这种情况下，应用程序应使用输出缓冲区的内容或提供新的输出缓冲区，按参数指定的chars字符数递增charsUsed参数，然后再次调用Convert该方法来处理剩余的输入。

completed也可以将参数设置为false，即使charsUsed参数和“char”跨度长度相等。 如果对象中仍存在尚未存储在Encoder缓冲区中的数据chars，则会出现这种情况。

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

public:
 virtual void Convert(char* chars, int charCount, System::Byte* bytes, int byteCount, bool flush, [Runtime::InteropServices::Out] int % charsUsed, [Runtime::InteropServices::Out] int % bytesUsed, [Runtime::InteropServices::Out] bool % completed);

[System.CLSCompliant(false)]
public virtual void Convert(char* chars, int charCount, byte* bytes, int byteCount, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(false)]
public virtual void Convert(char* chars, int charCount, byte* bytes, int byteCount, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(false)]
[System.Security.SecurityCritical]
public virtual void Convert(char* chars, int charCount, byte* bytes, int byteCount, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

[<System.CLSCompliant(false)>]
abstract member Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit
override this.Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit

[<System.CLSCompliant(false)>]
[<System.Runtime.InteropServices.ComVisible(false)>]
abstract member Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit
override this.Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit

[<System.CLSCompliant(false)>]
[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Security.SecurityCritical>]
abstract member Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit
override this.Convert : nativeptr<char> * int * nativeptr<byte> * int * bool * int * int * bool -> unit

参数

属性

CLSCompliantAttribute ComVisibleAttribute SecurityCriticalAttribute

例外

注解

请记住，对象 Encoder 在调用 Convert之间保存状态。 当应用程序使用数据流完成时，它应设置 flush 参数以确保 true 刷新状态信息。 使用此设置，编码器会忽略数据块末尾的无效字节并清除内部缓冲区。 作为逻辑单元的一部分（例如代理项对的高代理项）的任何剩余已处理数据都会根据当前的回退设置进行转换。

该方法 Convert 设计为在循环中使用，以编码任意数量的输入，例如从文件或流中读取的数据。 它将编码操作的输出存储在固定大小的缓冲区中。 GetBytes 如果输出缓冲区不够大，但 Convert 会尽可能填充空间并返回写入的字符读取和字节，将引发异常。 另请参阅主题 Encoding.GetBytes 以获取更多注释。

completed输出参数指示输入缓冲区中的所有数据是否已转换并存储在输出缓冲区中。 如果无法转换参数指定的字符数，且不能超过参数指定的字节数，则此参数设置为 < a0/>。 在这种情况下，应用程序应使用输出缓冲区的内容或提供新的输出缓冲区，按参数指定的chars字符数递增charsUsed参数，然后再次调用Convert该方法来处理剩余的输入。

completed即使参数相等，false也可以将参数设置为charsUsedcharCount。 如果对象中仍存在尚未存储在Encoder缓冲区中的数据chars，则会出现这种情况。

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

Source:

Encoder.cs

public:
 virtual void Convert(cli::array <char> ^ chars, int charIndex, int charCount, cli::array <System::Byte> ^ bytes, int byteIndex, int byteCount, bool flush, [Runtime::InteropServices::Out] int % charsUsed, [Runtime::InteropServices::Out] int % bytesUsed, [Runtime::InteropServices::Out] bool % completed);

public virtual void Convert(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex, int byteCount, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

[System.Runtime.InteropServices.ComVisible(false)]
public virtual void Convert(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex, int byteCount, bool flush, out int charsUsed, out int bytesUsed, out bool completed);

abstract member Convert : char[] * int * int * byte[] * int * int * bool * int * int * bool -> unit
override this.Convert : char[] * int * int * byte[] * int * int * bool * int * int * bool -> unit

[<System.Runtime.InteropServices.ComVisible(false)>]
abstract member Convert : char[] * int * int * byte[] * int * int * bool * int * int * bool -> unit
override this.Convert : char[] * int * int * byte[] * int * int * bool * int * int * bool -> unit

Public Overridable Sub Convert (chars As Char(), charIndex As Integer, charCount As Integer, bytes As Byte(), byteIndex As Integer, byteCount As Integer, flush As Boolean, ByRef charsUsed As Integer, ByRef bytesUsed As Integer, ByRef completed As Boolean)

参数

属性

ComVisibleAttribute

例外

示例

以下示例使用 Convert 该方法将 UTF-16 字符的文件转换为 UTF-8，然后使用 Convert 该方法将 UTF-8 字符转换回 UTF-16 字符。

// This code example demonstrates the Encoder.Convert() and Decoder.Convert methods.
// This example uses files for input and output, but any source that can be expressed
// as a stream can be used instead.

    using System;
    using System.Text;
    using System.IO;

    public class Sample
    {
    static void Main(string[] args)
        {
// Create a large file of UTF-16 encoded Unicode characters. The file is named Example.txt,
// and is used as input to the Encoder.Convert() method.

            CreateTestFile("Example.txt");

// Using an input file of UTF-16 encoded characters named Example.txt, create an output file
// of UTF-8 encoded bytes named UTF8.txt.

            EncoderConvert("Example.txt", "UTF8.txt", Encoding.UTF8);

// Using an input file of UTF-8 encoded bytes named UTF8.txt, create an output file
// of UTF-16 encoded characters named UTF16.txt.

            DecoderConvert("UTF8.txt", "UTF16.txt", Encoding.UTF8);
        }

// --------------------------------------------------------------------------------------------
// Use the Encoder.Convert() method to convert a file of characters to a file of encoded bytes.
// --------------------------------------------------------------------------------------------
        static void EncoderConvert(String inputFileName, String outputFileName, Encoding enc)
        {
// Convert an input file of characters to an output file of encoded bytes.
// StreamWriter could convert the input file for us, but we'll perform the conversion
// ourselves.

            FileStream fs = new FileStream(outputFileName, FileMode.Create);
            BinaryWriter outputFile = new BinaryWriter(fs);

// StreamReader will detect Unicode encoding from the Byte Order Mark that heads the input file.
            StreamReader inputFile = new StreamReader(inputFileName);

// Get an Encoder.
            Encoder encoder = enc.GetEncoder();

// Guarantee the output buffer large enough to convert a few characters.
            int UseBufferSize = 64;
            if (UseBufferSize < enc.GetMaxByteCount(10))
                    UseBufferSize = enc.GetMaxByteCount(10);
            byte[] bytes = new byte[UseBufferSize];

// Intentionally make the input character buffer larger than the output byte buffer so the
// conversion loop executes more than one cycle.

            char[] chars = new char[UseBufferSize * 4];
            int charsRead;
            do
            {
// Read at most the number of characters that will fit in the input buffer. The return
// value is the actual number of characters read, or zero if no characters remain.
                charsRead = inputFile.Read(chars, 0, UseBufferSize * 4);

                bool completed = false;
                int charIndex = 0;
                int charsUsed;
                int bytesUsed;

                while (!completed)
                {
// If this is the last input data, flush the encoder's internal buffer and state.

                    bool flush = (charsRead == 0);
                    encoder.Convert(chars, charIndex, charsRead - charIndex,
                                    bytes, 0, UseBufferSize, flush,
                                    out charsUsed, out bytesUsed, out completed);

// The conversion produced the number of bytes indicated by bytesUsed. Write that number
// of bytes to the output file.
                    outputFile.Write(bytes, 0, bytesUsed);

// Increment charIndex to the next block of characters in the input buffer, if any, to convert.
                    charIndex += charsUsed;
                }
            }
            while(charsRead != 0);

            outputFile.Close();
            fs.Close();
            inputFile.Close();
        }

// --------------------------------------------------------------------------------------------
// Use the Decoder.Convert() method to convert a file of encoded bytes to a file of characters.
// --------------------------------------------------------------------------------------------
        static void DecoderConvert(String inputFileName, String outputFileName, Encoding enc)
        {
// Convert an input file of of encoded bytes to an output file characters.
// StreamWriter could convert the input file for us, but we'll perform the conversion
// ourselves.

            StreamWriter outputFile = new StreamWriter(outputFileName, false, Encoding.Unicode);

// Read the input as a binary file so we can detect the Byte Order Mark.
            FileStream fs = new FileStream(inputFileName, FileMode.Open);
            BinaryReader inputFile = new BinaryReader(fs);

// Get a Decoder.
            Decoder decoder = enc.GetDecoder();

// Guarantee the output buffer large enough to convert a few characters.
            int UseBufferSize = 64;
            if (UseBufferSize < enc.GetMaxCharCount(10))
                    UseBufferSize = enc.GetMaxCharCount(10);
            char[] chars = new char[UseBufferSize];

// Intentionally make the input byte buffer larger than the output character buffer so the
// conversion loop executes more than one cycle.

            byte[] bytes = new byte[UseBufferSize * 4];
            int bytesRead;
            do
            {
// Read at most the number of bytes that will fit in the input buffer. The
// return value is the actual number of bytes read, or zero if no bytes remain.

                bytesRead = inputFile.Read(bytes, 0, UseBufferSize * 4);

                bool completed = false;
                int byteIndex = 0;
                int bytesUsed;
                int charsUsed;

                while (!completed)
                {
// If this is the last input data, flush the decoder's internal buffer and state.

                    bool flush = (bytesRead == 0);
                    decoder.Convert(bytes, byteIndex, bytesRead - byteIndex,
                                    chars, 0, UseBufferSize, flush,
                                    out bytesUsed, out charsUsed, out completed);

// The conversion produced the number of characters indicated by charsUsed. Write that number
// of characters to the output file.

                    outputFile.Write(chars, 0, charsUsed);

// Increment byteIndex to the next block of bytes in the input buffer, if any, to convert.
                    byteIndex += bytesUsed;
                }
            }
            while(bytesRead != 0);

            outputFile.Close();
            fs.Close();
            inputFile.Close();
        }

// --------------------------------------------------------------------------------------------
// Create a large file of UTF-16 encoded Unicode characters.
// --------------------------------------------------------------------------------------------
        static void CreateTestFile(String FileName)
        {
// StreamWriter defaults to UTF-8 encoding so explicitly specify Unicode, that is,
// UTF-16, encoding.
            StreamWriter file = new StreamWriter(FileName, false, Encoding.Unicode);

// Write a line of text 100 times.
            for (int i = 0; i < 100; i++)
            {
                file.WriteLine("This is an example input file used by the convert example.");
            }

// Write Unicode characters from U+0000 to, but not including, the surrogate character range.
            for (char c = (char)0; c < (char)0xD800; c++)
            {
                file.Write(c);
            }
            file.Close();
        }
    }

/*
This code example produces the following results:

(Execute the -dir- console window command and examine the files created.)

Example.txt, which contains 122,594 bytes (61,297 UTF-16 encoded characters).
UTF8.txt, which contains 169,712 UTF-8 encoded bytes.
UTF16.txt, which contains 122,594 bytes (61,297 UTF-16 encoded characters).

(Execute the -comp- console window command and compare the two Unicode files.)

>comp example.txt utf16.txt /L
Comparing example.txt and utf16.txt...
Files compare OK

(The two files are equal.)

*/

' This code example demonstrates the Encoder.Convert() and Decoder.Convert methods. 
' This example uses files for input and output, but any source that can be expressed
' as a stream can be used instead.

Imports System.Text
Imports System.IO

Public Class Sample
    Shared Sub Main(ByVal args() As String) 
        ' Create a large file of UTF-16 encoded Unicode characters. The file is named Example.txt, 
        ' and is used as input to the Encoder.Convert() method. 
        CreateTestFile("Example.txt")
        
        
        ' Using an input file of UTF-16 encoded characters named Example.txt, create an output file 
        ' of UTF-8 encoded bytes named UTF8.txt.
        EncoderConvert("Example.txt", "UTF8.txt", Encoding.UTF8)
        
        ' Using an input file of UTF-8 encoded bytes named UTF8.txt, create an output file 
        ' of UTF-16 encoded characters named UTF16.txt.
        DecoderConvert("UTF8.txt", "UTF16.txt", Encoding.UTF8)
    
    End Sub
    
    ' --------------------------------------------------------------------------------------------
    ' Use the Encoder.Convert() method to convert a file of characters to a file of encoded bytes.
    ' --------------------------------------------------------------------------------------------
    Shared Sub EncoderConvert(ByVal inputFileName As String, ByVal outputFileName As String, ByVal enc As Encoding) 
        ' Convert an input file of characters to an output file of encoded bytes.
        ' StreamWriter could convert the input file for us, but we'll perform the conversion 
        ' ourselves.
        Dim fs As New FileStream(outputFileName, FileMode.Create)
        Dim outputFile As New BinaryWriter(fs)
        
        ' StreamReader will detect Unicode encoding from the Byte Order Mark that heads the input file.
        Dim inputFile As New StreamReader(inputFileName)
        
        ' Get an Encoder.
        Dim encoder As Encoder = enc.GetEncoder()
        
        ' Guarantee the output buffer large enough to convert a few characters.
        Dim UseBufferSize As Integer = 64
        If UseBufferSize < enc.GetMaxByteCount(10) Then
            UseBufferSize = enc.GetMaxByteCount(10)
        End If
        Dim bytes(UseBufferSize) As Byte
        
        ' Intentionally make the input character buffer larger than the output byte buffer so the 
        ' conversion loop executes more than one cycle. 
        Dim chars(UseBufferSize * 4) As Char
        Dim charsRead As Integer
        Do
            ' Read at most the number of characters that will fit in the input buffer. The return 
            ' value is the actual number of characters read, or zero if no characters remain. 
            charsRead = inputFile.Read(chars, 0, UseBufferSize * 4)
            
            Dim completed As Boolean = False
            Dim charIndex As Integer = 0
            Dim charsUsed As Integer
            Dim bytesUsed As Integer
            
            While Not completed
                ' If this is the last input data, flush the encoder's internal buffer and state.
                Dim flush As Boolean = charsRead = 0
                encoder.Convert(chars, charIndex, charsRead - charIndex, bytes, 0, UseBufferSize, flush, charsUsed, bytesUsed, completed)
                
                ' The conversion produced the number of bytes indicated by bytesUsed. Write that number
                ' of bytes to the output file.
                outputFile.Write(bytes, 0, bytesUsed)
                
                ' Increment charIndex to the next block of characters in the input buffer, if any, to convert.
                charIndex += charsUsed
            End While
        Loop While charsRead <> 0
        
        outputFile.Close()
        fs.Close()
        inputFile.Close()
    
    End Sub
    
    ' --------------------------------------------------------------------------------------------
    ' Use the Decoder.Convert() method to convert a file of encoded bytes to a file of characters.
    ' --------------------------------------------------------------------------------------------
    Shared Sub DecoderConvert(ByVal inputFileName As String, ByVal outputFileName As String, ByVal enc As Encoding) 
        ' Convert an input file of of encoded bytes to an output file characters.
        ' StreamWriter could convert the input file for us, but we'll perform the conversion 
        ' ourselves.
        Dim outputFile As New StreamWriter(outputFileName, False, Encoding.Unicode)
        
        ' Read the input as a binary file so we can detect the Byte Order Mark.
        Dim fs As New FileStream(inputFileName, FileMode.Open)
        Dim inputFile As New BinaryReader(fs)
        
        ' Get a Decoder.
        Dim decoder As Decoder = enc.GetDecoder()
        
        ' Guarantee the output buffer large enough to convert a few characters.
        Dim UseBufferSize As Integer = 64
        If UseBufferSize < enc.GetMaxCharCount(10) Then
            UseBufferSize = enc.GetMaxCharCount(10)
        End If
        Dim chars(UseBufferSize) As Char
        
        ' Intentionally make the input byte buffer larger than the output character buffer so the 
        ' conversion loop executes more than one cycle. 
        Dim bytes(UseBufferSize * 4) As Byte
        Dim bytesRead As Integer
        Do
            ' Read at most the number of bytes that will fit in the input buffer. The 
            ' return value is the actual number of bytes read, or zero if no bytes remain. 
            bytesRead = inputFile.Read(bytes, 0, UseBufferSize * 4)
            
            Dim completed As Boolean = False
            Dim byteIndex As Integer = 0
            Dim bytesUsed As Integer
            Dim charsUsed As Integer
            
            While Not completed
                ' If this is the last input data, flush the decoder's internal buffer and state.
                Dim flush As Boolean = bytesRead = 0
                decoder.Convert(bytes, byteIndex, bytesRead - byteIndex, chars, 0, UseBufferSize, flush, bytesUsed, charsUsed, completed)
                
                ' The conversion produced the number of characters indicated by charsUsed. Write that number
                ' of characters to the output file.
                outputFile.Write(chars, 0, charsUsed)
                
                ' Increment byteIndex to the next block of bytes in the input buffer, if any, to convert.
                byteIndex += bytesUsed
            End While
        Loop While bytesRead <> 0
        
        outputFile.Close()
        fs.Close()
        inputFile.Close()
    
    End Sub
    
    ' --------------------------------------------------------------------------------------------
    ' Create a large file of UTF-16 encoded Unicode characters. 
    ' --------------------------------------------------------------------------------------------
    Shared Sub CreateTestFile(ByVal FileName As String) 
        ' StreamWriter defaults to UTF-8 encoding so explicitly specify Unicode, that is, 
        ' UTF-16, encoding.
        Dim file As New StreamWriter(FileName, False, Encoding.Unicode)
        
        ' Write a line of text 100 times.
        Dim i As Integer
        For i = 0 To 99
            file.WriteLine("This is an example input file used by the convert example.")
        Next i
        
        ' Write Unicode characters from U+0000 to, but not including, the surrogate character range.
        Dim c As Integer
        For c = 0 To &HD800
            file.Write(ChrW(c))
        Next c
        file.Close()
    
    End Sub
End Class

'
'This code example produces the following results:
'
'(Execute the -dir- console window command and examine the files created.)
'
'Example.txt, which contains 122,594 bytes (61,297 UTF-16 encoded characters).
'UTF8.txt, which contains 169,712 UTF-8 encoded bytes.
'UTF16.txt, which contains 122,594 bytes (61,297 UTF-16 encoded characters).
'
'(Execute the -comp- console window command and compare the two Unicode files.)
'
'>comp example.txt utf16.txt /L
'Comparing example.txt and utf16.txt...
'Files compare OK
'
'(The two files are equal.)
'

注解

请记住，对象 Encoder 在调用 Convert之间保存状态。 当应用程序使用数据流完成时，它应设置 flush 参数以确保 true 刷新状态信息。 使用此设置，编码器会忽略数据块末尾的无效字节并清除内部缓冲区。 作为逻辑单元的一部分（例如代理项对的高代理项）的任何剩余已处理数据都会根据当前的回退设置进行转换。

该方法 Convert 设计为在循环中使用，以编码任意数量的输入，例如从文件或流中读取的数据。 它将编码操作的输出存储在固定大小的缓冲区中。 GetBytes 如果输出缓冲区不够大，但 Convert 会尽可能填充空间并返回写入的字符读取和字节，将引发异常。 另请参阅文章 Encoding.GetBytes 以获取更多评论。

completed输出参数指示输入缓冲区中的所有数据是否已转换并存储在输出缓冲区中。 如果无法转换参数指定的字符数，且不能超过参数指定的字节数，则此参数设置为 < a0/>。 在这种情况下，应用程序应使用输出缓冲区的内容或提供新的输出缓冲区，按参数指定的chars字符数递增charsUsed参数，然后再次调用Convert该方法来处理剩余的输入。

completed即使参数相等，false也可以将参数设置为charsUsedcharCount。 如果对象中仍存在尚未存储在Encoder缓冲区中的数据chars，则会出现这种情况。