Question

我有一个程序可以将文件上传/下载到在线服务器上，有一个回调来报告进度并将其记录到文本文件中。该程序使用以下结构构建：

public void Upload(string source, string destination)
{     
        //Object containing Source and destination to pass to the threaded function
        KeyValuePair<string, string> file = new KeyValuePair<string, string>(source, destination);
       //Threading to make sure no blocking happens after calling upload Function
        Thread t = new Thread(new ParameterizedThreadStart(amazonHandler.TUpload));
        t.Start(file);
}

  private void TUpload(object fileInfo)
{
    KeyValuePair<string, string> file = (KeyValuePair<string, string>)fileInfo;
    /*
    Some Magic goes here,Checking The file and Authorizing Upload
    */
    var ftiObject = new FtiObject () 
        { FileNameOnHDD = file.Key,
            DestinationPath = file.Value,
            //Has more data used for calculations.
        };
          //Threading to make sure progress gets callback gets called.
        Thread t = new Thread(new ParameterizedThreadStart(amazonHandler.UploadOP));
            t.Start(ftiObject);
            //Signal used to stop progress untill uploadCompleted is called.
            uploadChunkDoneSignal.WaitOne();
         /*
          Some Extra Code
         */
}

 private void UploadOP(object ftiSentObject)
{
  FtiObject ftiObject = (FtiObject)ftiSentObject;
  /* 
   Some useless code to create the uri and prepare the ftiObject.
  */  

   // webClient.UploadFileAsync will open a thread that 
   // will upload the file and report
   // progress/complete using registered callback functions.

  webClient.UploadFileAsync(uri, "PUT", ftiObject.FileNameOnHDD, ftiObject);
}

我收到了一个注册到Webclient的UploadProgressChanged事件的回调，但每次发送的请求都会被调用两次。

 void UploadProgressCallback(object sender, UploadProgressChangedEventArgs e)
    {
        FtiObject ftiObject = (FtiObject )e.UserState;
                Logger.log(ftiObject.FileNameOnHDD, (double)e.BytesSent ,e.TotalBytesToSend);
    }

日志输出：

  Filename: C:\Text1.txt  Uploaded:1024 TotalFileSize: 665241
  Filename: C:\Text1.txt  Uploaded:1024 TotalFileSize: 665241
  Filename: C:\Text1.txt  Uploaded:2048 TotalFileSize: 665241
  Filename: C:\Text1.txt  Uploaded:2048 TotalFileSize: 665241
  Filename: C:\Text1.txt  Uploaded:3072 TotalFileSize: 665241
  Filename: C:\Text1.txt  Uploaded:3072 TotalFileSize: 665241
  Etc...

我正在使用观察者观看网络流量，并且只发送了1个请求。

有些我怎么不能弄清楚为什么回调被调用两次，我怀疑是回调是被每个线程打开（主要上传和TUpload），但是我不知道如何测试这是否是原因

注意：许多/ ** / Comments背后的原因是表明函数不仅仅是打开线程，而且正在使用线程来确保不会发生阻塞（有几个“Signal.WaitOne（） “围绕同步代码”

Answer 1

如果你在回调上设置断点，你不能检查callstack以查看来电的来源吗？如果您使用的是Visual Studio。

Answer 2

您是否在上传ProgressChangedEventArgs中检查了API确实没有使用不同信息回调两次？

C＃：每个Sent Request都会调用两次我的回调函数

2 个答案: