my Gridview still freezes in backgroundworker Dowork while using this.invoke(MethodInvoker)delegate

Question

I want to update my gridview gradually while retrieving data

I've a backgroundworker Do work function as follows

    private void backGroundWrkr_DoWork(object sender, DoWorkEventArgs e)
    {
        DataTable dtInstant = new DataTable();

        for (int i = 0; i < allFiles.Count; i++)
        {
            if (backGroundWrkr.CancellationPending)
            {
                e.Cancel = true;
                return;
            }

               myApp.processFile(allFiles[i]);


              this.Invoke((MethodInvoker)delegate
              {
               myGrdVw.DataSource = myApp.dtResults;
              });


            backGroundWrkr.ReportProgress(100 * (i + 1) / allFiles.Count);
        }
        backGroundWrkr.ReportProgress(100);

    }

and this is my Report Progress function

 private void backGroundWrkr_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar.Value = e.ProgressPercentage;

        }

and this is my backGroundWrkr complete

private void backGroundWrkr_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            progressBar.Visible = false;
            allFiles.Clear();
        }

I've tried also BeginInvoke instead of Invoke and still my gridview freezes! My logic of proccessing files has no problem because in case I put datagridview binding in workercomplete it binds successfully

Freezes perhaps because the background worker is too fast? Can you place a sleep timer in it? — Dmitry Sadakov, Aug 07 '15 at 23:57
I've tried Thread.Sleep(1000) before invoking and nothing happens the same freeze but with slow process to some extent — user690069, Aug 08 '15 at 00:16
Why didn't you put this instruction " myGrdVw.DataSource = myApp.dtResults" in backGroundWrkr_ProgressChanged ? — Graffito, Aug 08 '15 at 00:33

score 1 · Accepted Answer · answered Aug 08 '15 at 01:12

After 2 days of search and unsuccessful trials I've solved it as follows While binding it seems that the backgroundworker is working in the datatable so I bind a copy of the results datatable and it solves my problem

private void backGroundWrkr_DoWork(object sender, DoWorkEventArgs e)
{
    DataTable dtInstant = new DataTable();

    for (int i = 0; i < allFiles.Count; i++)
    {
        if (backGroundWrkr.CancellationPending)
        {
            e.Cancel = true;
            return;
        }

           myApp.processFile(allFiles[i]);


          this.Invoke((MethodInvoker)delegate
          {
           myGrdVw.DataSource = myApp.dtResults.copy();
          });


        backGroundWrkr.ReportProgress(100 * (i + 1) / allFiles.Count);
    }
    backGroundWrkr.ReportProgress(100);

}

Thanks all for your help!

score 0 · Answer 2 · answered Aug 08 '15 at 00:59

0

Try to bind the datasource only once (i.e. before calling DoWork) and execute myGrdVw.Invalidate() in backGroundWrkr_ProgressChanged.

answered Aug 08 '15 at 00:59

Graffito

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my Gridview still freezes in backgroundworker Dowork while using this.invoke(MethodInvoker)delegate

2 Answers2