FileStream.WriteByte(Byte) 方法

定义

一个字节写入文件流中的当前位置。

public:
 override void WriteByte(System::Byte value);
public override void WriteByte (byte value);
override this.WriteByte : byte -> unit
Public Overrides Sub WriteByte (value As Byte)

参数

value
Byte

要写入流的字节。

例外

流已关闭。

流不支持写入。

示例

下面的代码示例演示如何将数据写入文件、字节字节,然后验证数据是否已正确写入。

using namespace System;
using namespace System::IO;
int main()
{
   String^ fileName =  "Test@##@.dat";
   
   // Create random data to write to the file.
   array<Byte>^dataArray = gcnew array<Byte>(100000);
   (gcnew Random)->NextBytes( dataArray );
   FileStream^ fileStream = gcnew FileStream( fileName,FileMode::Create );
   try
   {
      
      // Write the data to the file, byte by byte.
      for ( int i = 0; i < dataArray->Length; i++ )
      {
         fileStream->WriteByte( dataArray[ i ] );

      }
      
      // Set the stream position to the beginning of the file.
      fileStream->Seek( 0, SeekOrigin::Begin );
      
      // Read and verify the data.
      for ( int i = 0; i < fileStream->Length; i++ )
      {
         if ( dataArray[ i ] != fileStream->ReadByte() )
         {
            Console::WriteLine( "Error writing data." );
            return  -1;
         }

      }
      Console::WriteLine( "The data was written to {0} "
      "and verified.", fileStream->Name );
   }
   finally
   {
      fileStream->Close();
   }

}
using System;
using System.IO;

class FStream
{
    static void Main()
    {
        const string fileName = "Test#@@#.dat";

        // Create random data to write to the file.
        byte[] dataArray = new byte[100000];
        new Random().NextBytes(dataArray);

        using(FileStream
            fileStream = new FileStream(fileName, FileMode.Create))
        {
            // Write the data to the file, byte by byte.
            for(int i = 0; i < dataArray.Length; i++)
            {
                fileStream.WriteByte(dataArray[i]);
            }

            // Set the stream position to the beginning of the file.
            fileStream.Seek(0, SeekOrigin.Begin);

            // Read and verify the data.
            for(int i = 0; i < fileStream.Length; i++)
            {
                if(dataArray[i] != fileStream.ReadByte())
                {
                    Console.WriteLine("Error writing data.");
                    return;
                }
            }
            Console.WriteLine("The data was written to {0} " +
                "and verified.", fileStream.Name);
        }
    }
}
Imports System.IO
Imports System.Text

Class FStream

    Shared Sub Main()

        Const fileName As String = "Test#@@#.dat"

        ' Create random data to write to the file.
        Dim dataArray(100000) As Byte
        Dim randomGenerator As New Random()
        randomGenerator.NextBytes(dataArray)

        Dim fileStream As FileStream = _
            new FileStream(fileName, FileMode.Create)
        Try

            ' Write the data to the file, byte by byte.
            For i As Integer = 0 To dataArray.Length - 1
                fileStream.WriteByte(dataArray(i))
            Next i

            ' Set the stream position to the beginning of the stream.
            fileStream.Seek(0, SeekOrigin.Begin)

            ' Read and verify the data.
            For i As Integer = 0 To _
                CType(fileStream.Length, Integer) - 1

                If dataArray(i) <> fileStream.ReadByte() Then
                    Console.WriteLine("Error writing data.")
                    Return
                End If
            Next i
            Console.WriteLine("The data was written to {0} " & _
                "and verified.", fileStream.Name)
        Finally
            fileStream.Close()
        End Try
    
    End Sub
End Class

注解

此方法重写 WriteByte

用于 WriteByte 将字节 FileStream 写入高效字节。 如果流已关闭或不可写入,将引发异常。

备注

使用 CanWrite 属性确定当前实例是否支持写入。 有关附加信息,请参见 CanWrite

继承者说明

创建 Stream 一个新的单字节数组,然后调用 Write(Byte[], Int32, Int32)默认实现。 虽然这是正式正确的,但它效率低下。 任何具有内部缓冲区的流都应重写此方法,并提供一个更高效的版本,直接读取缓冲区,避免每次调用时分配额外的数组分配。

有关常见文件和目录操作的列表,请参阅 常见 I/O 任务

适用于

另请参阅