Question

I am trying to create a thread that contains a form progress bar (just a GIF image).
I have called StartProgress() right before a large method. Basically when the thread starts it loads up the ProgressBar form (which I want to show all the time, and just hide it when it’s not needed) and with ProgressActive set to true, it should display the form until ProgressActive is false, then the form should be hidden (until progress is active again). Here is what I have so far, but it freezes up on me 🙁

    public static string ProgressInfo="Test";
    public static bool ProgressActive=true;
    public static bool ThreadStarted = false;

    public static void StartProgress()
    {
        while (!ThreadStarted)
        {
            Thread t = new Thread(new ThreadStart(Progress));
            ThreadStarted = true;
            t.Start();
        }

    }
    public static void Progress()
    {
        while (ThreadStarted)
        {

            LoadingBar lb = new LoadingBar();
            lb.Show();
            lb.TopMost = true;
            while (ThreadStarted)
            {
                if (ProgressActive)
                {
                    lb.Visible = true;
                    lb.lblLoadingStatus.Text = ProgressInfo;
                }
                else
                {
                    lb.Visible = false;
                }
                Thread.Sleep(1000);
            }
        }

    }

EDIT: I am trying to do this within a static class.

Answer 1

The freezing is due to the fact you are trying to change your progress bar contained on the UI thread from your worker thread. I would recommend raising an event from within your worker Progress function to a handler on the UI thread. You will need to marshall the call to the handler on the thread as below.

private object _lock = new object(); //should have class scope

private void ShowProgressControl(EventArgs e)
{
  if (this.InvokeRequired)
  {
    lock (_lock)
    {
      EventHandler d = new EventHandler(ShowProgressControl);
      this.Invoke(d, new object[] { e });
      return;
    }
  }
  else
  {
    //Show your progress bar.
  }
}

Enjoy!