BackgroundWorker update elapsed time label using stopwatch, freeze due to invoke C#

Question

I'm Trying to create a Live Stopwatch which is running in a background worker inside a user control and I'm updating the label which is the elapsed time in the UI using Invoke Method it works fine when 2 background workers are running simultaneously.

i noticed that the problem is that I'm trying to invoke the label each second and that is multiplied by the number of the user controls i create so it freezes i tried to comment the invoke method it just worked fine but i couldn't update the label with the elapsed time without invoke method.

public void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
     Stopwatch stopWatch = new Stopwatch();
     stopWatch.Start();
     while (!backgroundWorker1.CancellationPending)
     {
         TimeSpan ts = stopWatch.Elapsed;
         string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}", ts.Hours,ts.Minutes, ts.Seconds);               
         label2.Invoke((MethodInvoker)delegate
         {
             label2.Text = elapsedTime;
         });
     }
     stopWatch.Stop();
}

this is an image for the generated user controls that uses stopwatches https://i.stack.imgur.com/mAQLP.png .

how could i update the label with the elapsed time without the application freezes considering that i may have more than one user control running simultaneously.

`Invoke` really does not deserve blame here - trying to constantly update element on the form will freeze form irrespective how you do that. — Alexei Levenkov, Sep 25 '19 at 00:37
@AlexeiLevenkov i noticed that it's not the best way to do that — Abdulrahman Bahaa, Sep 25 '19 at 01:07
@AlexeiLevenkov so there is no goof way to make a live stopwatch in the form ? — Abdulrahman Bahaa, Sep 25 '19 at 01:15

Abdulrahman Bahaa · Accepted Answer · 2022-04-01T11:53:38.347

I figured out the Timer should be used instead of Background worker which can be used for such problems.

Stopwatch sw = new Stopwatch();

private void timer1_Tick(object sender, EventArgs e)
{
    long h = sw.Elapsed.Hours;
    long m = sw.Elapsed.Minutes;
    long s = sw.Elapsed.Seconds;
    long t = sw.Elapsed.Ticks;

    string strH = (h < 10) ? "0" + h : h + "";
    string strM = (m < 10) ? "0" + m : m + "";
    string strS = (s < 10) ? "0" + s : s + "";
    string AllTime = strH + ":" + strM +":"+ strS;

    label2.Text = AllTime;
}```

BackgroundWorker update elapsed time label using stopwatch, freeze due to invoke C#

1 Answers1