How To Start And Stop A Continuously Running Background Worker Using A Button

Question

Let\'s say I have a background worker like this:

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
             while(true)
          


        

Answer 1

By stop do you really mean stop or do you mean pause? If you mean stop, then this is a piece of cake. Create a button click event handler for the button you want to be responsible for starting the background worker and a button click event handler for the one responsible for stopping it. On your start button, make a call to the background worker method that fires the do_work event. Something like this:

private void startButton_Click(System.Object sender, 
    System.EventArgs e)
{
    // Start the asynchronous operation.
    backgroundWorker1.RunWorkerAsync();
}

On your stop button, make a call to the method that sets the background worker's CancellationPending to true, like this:

private void cancelAsyncButton_Click(System.Object sender, 
    System.EventArgs e)
{   
    // Cancel the asynchronous operation.
    this.backgroundWorker1.CancelAsync();
}

Now don't forget to check for the CancelationPending flag inside your background worker's doWork. Something like this:

   private void KillZombies(BackgroundWorker worker, DoWorkEventArgs e)
   {
        while (true)
        {
            if (worker.CancellationPending)
           {   
              e.Cancel = true;
           }
        }
   }

And your doWork method:

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
             BackgroundWorker worker = sender as BackgroundWorker;
             KillZombies(worker, e);
        }

I hope this can steer you in the right direction. Some further readings:

http://msdn.microsoft.com/en-us/library/b2zk6580(v=VS.90).aspx

http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

http://msdn.microsoft.com/en-us/library/waw3xexc.aspx