在C＃winforms中，为什么UI标签没有更新并跟上backgroundworker progresschanged事件？

Question

I am updating a label text on a backgroundworker progressChanged event (literally one 1 line of code in this event callback).

Its updating about 50 times in around 45 seconds and the issue is that the UI only seems to update about 10 times. So it appears that the UI is not "keeping up" with the number of events.

Is there anyway to help improve this. I see folks suggestions APplication.DoEvents() but always thought that was a bit dodgy.

void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
      lblProgress.Text = "Updating Progress: " +  e.ProgressPercentage;
}

Is there a recommended practice here so i see every update on the UI?

Answer 1

Try to call:

this.lblProgress.Refresh();

after setting the Text-Property

Answer 2

I have only had this happen once before, and at the time, the best method I found was to just call update:

void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
      lblProgress.Text = "Updating Progress: " +  e.ProgressPercentage;
      lblProgress.Update();
}

Depending on how important your label's text is, you could call Refresh() instead for a more immediate redraw.