CODEWITHSUNDEEP
c#multithreading
user1201412
user1201412

Reputation: 31

c# thread and a waiting form

I connect to a webserive. While the webservice is connected i want to have a waiting form with an animated gif inside of it. The waiting form is correctly displayed but the animated give is not animated it is fixed.

Can anybody help me. I have already tried : DoEvents but the gif is still not animated. 

        // Create the new thread object
        Thread NewThread = new Thread(new ThreadStart(RunThread));           

        // Start the new thread.
        NewThread.Start();

        // Inform everybody that the main thread is waiting
        FRM_Wait waitingDialog = new FRM_Wait();
        waitingDialog.Show();
        waitingDialog.Activate();
        Application.DoEvents(); 

        // Wait for NewThread to terminate.
        NewThread.Join();

        // And it's done.
        waitingDialog.Close();
        MessageBox.Show("Upload erfolgreich erledigt.", "Upload Erfolgreich",
             MessageBoxButtons.OK, MessageBoxIcon.Exclamation); 
    }

    public void RunThread()
    {         
         mfsportservicedev.ServiceSoapClient servicedev = new mfsportservicedev.ServiceSoapClient();

        int status = servicedev.addEvent(videosNames, videos);         
    }

Upvotes: 1

Views: 2804

Answers (4)

Brian Gideon
Brian Gideon

Reputation: 48949

Thread.Join is a blocking call that does not pump messages so that is your problem. It is typically advised to avoid calling any kind of synchronization mechanism that causes the UI thread to block.

Here is a solution using the Task class and the Invoke marshaling technique.

private void async InitiateWebService_Click(object sender, EventArgs args)
{
  FRM_Wait waitingDialog = new FRM_Wait();
  waitingDialog.Show();

  Task.Factory.StartNew(
    () =>
    {
      mfsportservicedev.ServiceSoapClient servicedev = new mfsportservicedev.ServiceSoapClient();
      int status = servicedev.addEvent(videosNames, videos);
      waitingDialog.Invoke(
        (Action)(() =>
        {
          waitingDialog.Close();
        }));
    });
}

Here is a solution using a raw Thread.

private void async InitiateWebService_Click(object sender, EventArgs args)
{
  FRM_Wait waitingDialog = new FRM_Wait();
  waitingDialog.Show();

  var thread = new Thread(
    () =>
    {
      mfsportservicedev.ServiceSoapClient servicedev = new mfsportservicedev.ServiceSoapClient();
      int status = servicedev.addEvent(videosNames, videos);
      waitingDialog.Invoke(
        (Action)(() =>
        {
          waitingDialog.Close();
        }));
    });

  thread.Start();
}

C# 5.0 makes this kind of pattern even easier with its new async and await keywords1.

private void async InitiateWebService_Click(object sender, EventArgs args)
{
  FRM_Wait waitingDialog = new FRM_Wait();
  waitingDialog.Show();

  await Task.Run(
    () =>
    {
      mfsportservicedev.ServiceSoapClient servicedev = new mfsportservicedev.ServiceSoapClient();
      int status = servicedev.addEvent(videosNames, videos);         
    });

  waitingDialog.Close();
}

1Not yet released.

Upvotes: 0

Matt Burland
Matt Burland

Reputation: 45135

You problem is here:

NewThread.Join();

This blocks the UI thread until NewThread ends.

Here's one way to do it:

private myDelegate;
// ...
myDelegate = new Action(RunThread);
myDelegate.BeginInvoke(new AsyncCallback(MyCallback),null);
// You RunThread method is now running on a separate thread
// Open your wait form here
// ...
// This callback function will be called when you delegate ends
private void MyCallback(IAsyncResult ar)
{
     myDelegate.EndInvoke(ar);
     // Note this is still not the UI thread, so if you want to do something with the UI you'll need to do it on the UI thread.
     // using either Control.Invoke (for WinForms) or Dispatcher.Invoke (for WPF)
}

Upvotes: 0

squelos
squelos

Reputation: 1189

The problem is coming from your join. join is synchronous, so basically you are making your UI wait till the thread finishes its work.

You want to use a callback function to come back to your UI.

Edit : ive been skeetified

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1499750

Don't call Join on a thread from within the UI thread. Instead, disable any controls you don't want to act on until the task has completed (e.g. buttons) and then call back into the UI thread when the operation has completed - so move the "And it's done" code into a new method which is invoked at the end of the operation. If you're using .NET 4, I'd suggest using the TPL for this, as it makes it easier to represent "a task which is in progress" and to add a continuation to it. (It's also a good start for what will become the idiomatic way of doing async operations in .NET 4.5.)

Upvotes: 3

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