cancel background worker exception in e.result

Question

i have a serious problem with background worker. code is working if task is ending regular. when i cancel the background task i get an system.invalidoperationexception in the RunWorkerCompleted function for e.Result. what is wrong? thank you.

here is my cod:

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
  if (backgroundWorker.CancellationPending == true)
    e.Cancel = true;
  e.Result = resultList;
}


private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
  if (e.Error != null)
    List<Object> resultList = (List<Object>)e.Result;
} 

Answer 1

This is by design, the Result property getter will throw when DoWork was cancelled or threw an exception. Simply check for that:

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if (!e.Cancelled && e.Error == null) {
       List<Object> resultList = (List<Object>)e.Result;
       // etc..
    }
}