FtpWebRequest.EndGetRequestStream(IAsyncResult) 方法

  • 參考

定義

命名空間:
System.Net
組件:
System.Net.Requests.dll
組件:
System.dll
組件:
netstandard.dll
來源:
FtpWebRequest.cs
來源:
FtpWebRequest.cs
來源:
FtpWebRequest.cs

結束由 BeginGetRequestStream(AsyncCallback, Object) 所啟動的暫止非同步作業。

public:
 override System::IO::Stream ^ EndGetRequestStream(IAsyncResult ^ asyncResult);
public override System.IO.Stream EndGetRequestStream (IAsyncResult asyncResult);
override this.EndGetRequestStream : IAsyncResult -> System.IO.Stream
Public Overrides Function EndGetRequestStream (asyncResult As IAsyncResult) As Stream

參數

asyncResult
IAsyncResult

作業啟動時所傳回的 IAsyncResult 物件。

傳回

Stream

與這個執行個體關聯的可寫入 Stream 執行個體。

例外狀況

ArgumentNullException

asyncResult 為 null。

ArgumentException

未呼叫 BeginGetRequestStream(AsyncCallback, Object)，取得 asyncResult。

InvalidOperationException

已針對 asyncResult 所識別的作業，呼叫這個方法。

範例

下列程式碼範例示範結束非同步作業以取得要求的資料流程。 此程式碼範例是類別概觀所提供較大範例的 FtpWebRequest 一部分。

private:
   static void EndGetStreamCallback( IAsyncResult^ ar )
   {
      FtpState^ state = dynamic_cast<FtpState^>(ar->AsyncState);
      Stream^ requestStream = nullptr;

      // End the asynchronous call to get the request stream.
      try
      {
         requestStream = state->Request->EndGetRequestStream( ar );

         // Copy the file contents to the request stream.
         const int bufferLength = 2048;
         array<Byte>^buffer = gcnew array<Byte>(bufferLength);
         int count = 0;
         int readBytes = 0;
         FileStream^ stream = File::OpenRead( state->FileName );
         do
         {
            readBytes = stream->Read( buffer, 0, bufferLength );
            requestStream->Write( buffer, 0, bufferLength );
            count += readBytes;
         }
         while ( readBytes != 0 );
         Console::WriteLine( "Writing {0} bytes to the stream.", count );

         // IMPORTANT: Close the request stream before sending the request.
         requestStream->Close();

         // Asynchronously get the response to the upload request.
         state->Request->BeginGetResponse( gcnew AsyncCallback( EndGetResponseCallback ), state );
      }
      // Return exceptions to the main application thread.
      catch ( Exception^ e ) 
      {
         Console::WriteLine( "Could not get the request stream." );
         state->OperationException = e;
         state->OperationComplete->Set();
         return;
      }
   }

private static void EndGetStreamCallback(IAsyncResult ar)
{
    FtpState state = (FtpState) ar.AsyncState;

    Stream requestStream = null;
    // End the asynchronous call to get the request stream.
    try
    {
        requestStream = state.Request.EndGetRequestStream(ar);
        // Copy the file contents to the request stream.
        const int bufferLength = 2048;
        byte[] buffer = new byte[bufferLength];
        int count = 0;
        int readBytes = 0;
        FileStream stream = File.OpenRead(state.FileName);
        do
        {
            readBytes = stream.Read(buffer, 0, bufferLength);
            requestStream.Write(buffer, 0, readBytes);
            count += readBytes;
        }
        while (readBytes != 0);
        Console.WriteLine ("Writing {0} bytes to the stream.", count);
        // IMPORTANT: Close the request stream before sending the request.
        requestStream.Close();
        // Asynchronously get the response to the upload request.
        state.Request.BeginGetResponse(
            new AsyncCallback (EndGetResponseCallback),
            state
        );
    }
    // Return exceptions to the main application thread.
    catch (Exception e)
    {
        Console.WriteLine("Could not get the request stream.");
        state.OperationException = e;
        state.OperationComplete.Set();
        return;
    }
}

備註

如果作業尚未完成，方法會 EndGetRequestStream 封鎖直到作業完成為止。 若要判斷作業是否已完成，請在呼叫 EndGetRequestStream 之前檢查 IsCompleted 屬性。

除了「例外狀況」中所指出的例外狀況之外， EndGetRequestStream 還會重新擲回開啟資料流程以進行寫入時擲回的例外狀況。

注意

在應用程式中啟用網路追蹤時，這個成員會輸出追蹤資訊。 如需詳細資訊，請參閱.NET Framework中的網路追蹤。

適用於

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