CODEWITHSUNDEEP
c#winforms
arjun
arjun

Reputation: 645

How to stop backgroundworker

Almost all the example of backgroundworker consists of for loop. But my requirement do not need any loop. I have following code running i backgroundworker. How do i cancel the worker process without using the for loop

 void form_DoWork(LoadingProgress sender, DoWorkEventArgs e)
    {

            //for (int i = 0; i < 100; i++)
        //{


        //    System.Threading.Thread.Sleep(50);
        //    sender.SetProgress(i, "Step " + i.ToString() + " / 100...");
        //    if (sender.CancellationPending)
        //    {
        //        e.Cancel = true;
        //        return;
        //    }
        //}
              // heavy database process       
             SomeClass.BulkInsert(ExportLine);
        }  


   private void ButtonCancelClick(object sender, EventArgs e)
    {
        //notify the background worker we want to cancel
        worker.CancelAsync();
      //disable the cancel button and change the status text
        buttonCancel.Enabled = false;
        labelStatus.Text = CancellingText;
    }

Upvotes: 1

Views: 757

Answers (1)

Steven P
Steven P

Reputation: 1996

I wouldn't use BackgroundWorker if that's what you need to do. Since your class doesn't provide any way to provide progress updates, the only thing it's giving you is marshalling the RunWorkerCompleted method.

Create a Thread class, keep a reference to it and abort if you need to. Just make sure that when your background work is finished, you call Invoke if you update any controls with the results.

EDIT:

Here's a primitive example of how it could work. (note: this may not compile, i didn't write it in the IDE).

Thread _dbThread;

void DoLongRunningQueryAsync()
    {
        bool dbWorkFinished = false;
        _dbThread = new Thread(() =>
        {
             // heavy database process       
             SomeClass.BulkInsert(ExportLine);
             dbWorkFinished = true;
        });
        Thread monitorThread = new Thread(() =>
        {
             Thread.Sleep(5000);
             if (!dbWorkFinished)
             {
                 //Db work took too long. Abort
                 _dbThread.Abort();
                 this.Invoke(() => MessageBox.Show("Db work took too long. Query aborted"); );
             }
        });
        _dbThread.Start();
        monitorThread.Start();
     }  


   private void ButtonCancelClick(object sender, EventArgs e)
    {
        _dbThread.Abort()
    }

Upvotes: 2

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