Question

I’ve been struggling with a Background Worker for sometime, and I’m beginning to wonder if there are limits to what one can do with a bw. I’m trying to utilize a bw to handle a TCPIP exchange while updating the UI using its ProgressChanged Method. I know the UI update is ok, but my DoWork routine (shown below) sometimes causes the bw thread to disappear/stop working. Has anyone else had this problem?

private void TCPIP_DoWork(object sender, DoWorkEventArgs e)
{
   int a = 0;
   s.Send(System.Text.Encoding.ASCII.GetBytes("s"));
   if (worker.CancellationPending == true)
   {
      s.Send(System.Text.Encoding.ASCII.GetBytes("t"));
   }
   else
   {
      try
      {
         a = s.Available;
         s.Receive(bytes);
         Thread.Sleep(25);
         using (Stream fileStream = new FileStream(@sbpFile.Text, 
                         FileMode.Append, FileAccess.Write, FileShare.None))
         {
             using (BinaryWriter bw = new BinaryWriter(fileStream))
             {
                if (a == 0)
                   Thread.Sleep(20);
                else if (a < 1023)
                {
                   bw.Write(bytes, 0, a);
                   Thread.Sleep(20);
                }
                else
                {
                   bw.Write(bytes, 0, 1024);
                   Thread.Sleep(20);
                }
             }
          }
       }
       catch(Exception e)
       {
          Console.WriteLine("{0} Exception.", e);
       }
   }
}

NOTE: The only reason those Thread.Sleep() operations are in there are because they seem to be the temporary fix for having the bw not trip over itself…

Answer 1

Try to check Error property on RunWorkerCompleted event handler. Maybe you get some exception, which in not handled by your code.

void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
   if (e.Error != null)
      Console.WriteLine("{0} Exception.", e.Error);        
   // etc
}