FileStream.EndWrite(IAsyncResult) FileStream.EndWrite(IAsyncResult) FileStream.EndWrite(IAsyncResult) FileStream.EndWrite(IAsyncResult) Method

定义

结束异步写入操作,在 I/O 操作完成之前一直阻止。Ends an asynchronous write operation and blocks until the I/O operation is complete. (请考虑改用 WriteAsync(Byte[], Int32, Int32, CancellationToken)。)(Consider using WriteAsync(Byte[], Int32, Int32, CancellationToken) instead.)

public:
 override void EndWrite(IAsyncResult ^ asyncResult);
public override void EndWrite (IAsyncResult asyncResult);
override this.EndWrite : IAsyncResult -> unit
Public Overrides Sub EndWrite (asyncResult As IAsyncResult)

参数

asyncResult
IAsyncResult IAsyncResult IAsyncResult IAsyncResult

挂起的异步 I/O 请求。The pending asynchronous I/O request.

异常

流已关闭或出现了内部错误。The stream is closed or an internal error has occurred.

示例

此代码示例是为提供一个更大示例的一部分FileStream(String, FileMode, FileAccess, FileShare, Int32, Boolean)构造函数。This code example is part of a larger example provided for the FileStream(String, FileMode, FileAccess, FileShare, Int32, Boolean) constructor.

   static void EndWriteCallback( IAsyncResult^ asyncResult )
   {
      State^ tempState = dynamic_cast<State^>(asyncResult->AsyncState);
      FileStream^ fStream = tempState->FStream;
      fStream->EndWrite( asyncResult );
      
      // Asynchronously read back the written data.
      fStream->Position = 0;
      asyncResult = fStream->BeginRead( tempState->ReadArray, 0, tempState->ReadArray->Length, gcnew AsyncCallback( &FStream::EndReadCallback ), tempState );
      
      // Concurrently do other work, such as 
      // logging the write operation.
   }

};


static void EndWriteCallback(IAsyncResult asyncResult)
{
    State tempState = (State)asyncResult.AsyncState;
    FileStream fStream = tempState.FStream;
    fStream.EndWrite(asyncResult);

    // Asynchronously read back the written data.
    fStream.Position = 0;
    asyncResult = fStream.BeginRead(
        tempState.ReadArray, 0 , tempState.ReadArray.Length, 
        new AsyncCallback(EndReadCallback), tempState);

    // Concurrently do other work, such as 
    // logging the write operation.
}
Private Shared Sub EndWriteCallback(asyncResult As IAsyncResult)
    Dim tempState As State = _
        DirectCast(asyncResult.AsyncState, State)
    Dim fStream As FileStream = tempState.FStream
    fStream.EndWrite(asyncResult)

    ' Asynchronously read back the written data.
    fStream.Position = 0
    asyncResult = fStream.BeginRead( _ 
        tempState.ReadArray, 0 , tempState.ReadArray.Length, _
        AddressOf EndReadCallback, tempState)

    ' Concurrently do other work, such as 
    ' logging the write operation.
End Sub

注解

在.NET Framework 4 和更早版本中,您必须使用如下所示方法BeginWriteEndWrite实现异步文件操作。In the .NET Framework 4 and earlier versions, you have to use methods such as BeginWrite and EndWrite to implement asynchronous file operations. 这些方法是在中仍然可用.NET Framework 4.5.NET Framework 4.5以支持旧版代码; 但是,新的异步方法,如ReadAsyncWriteAsyncCopyToAsync,和FlushAsync,帮助您更轻松地实现异步文件操作。These methods are still available in the .NET Framework 4.5.NET Framework 4.5 to support legacy code; however, the new async methods, such as ReadAsync, WriteAsync, CopyToAsync, and FlushAsync, help you implement asynchronous file operations more easily.

此方法重写 EndWriteThis method overrides EndWrite.

EndWrite 必须在上一次调用每个IAsyncResultBeginWriteEndWrite must be called exactly once on every IAsyncResult from BeginWrite. EndWrite 之前已完成 I/O 操作将阻塞。EndWrite will block until the I/O operation has completed.

适用于

另请参阅