Update Label while processing in Windows Forms

Question

What is the best way to update a label on a Windows Forms application while processing?

I have a loop that does some processing to files on the user's system when the user clicks a button.

foreach (System.IO.FileInfo f in dir.GetFiles("*.txt")) {    // Do processing    // Show progress bar    // Update Label on Form, "f.Name is done processing, now processing..." } 

What would be some sample code?

What exactly is this called? Is it threading or delegates?

Answer 1

A quick fix for you would be:

Label1.Text = f.Name + " is done processing, now processing..."; Label1.Refresh(); 

You really want to avoid DoEvents, otherwise you'll have problems if your user repeatedly presses buttons on your form.

Answer 2

You should be doing this on another thread, and then updating your UI thread from that thread. You are blocking further processing by performing this work on the UI thread.

If you can't move this code to the UI thread, then you could always call Application.DoEvents, but I strongly suggest you explore these options first:

• System.ComponentModel.BackgroundWorker
• System.Threading.ThreadPool
• System.Threading.Thread
• System.Threading.Tasks namespace