protected void StartLongOperation()
{
waitLongOperationCompleted = AsyncOperationManager.CreateOperation(null);
LongOperation longOperation = new LongOperation(DoWork);
longOperation.CancellingTimeoutMilliSeconds = 10000;
longOperation.CancellingTimeoutExpired += new EventHandler(LongOperation_CancellingTimeoutExpired);
longOperation.Completed += new EventHandler <LongOperationCompletedEventArgs>(LongOperation_Completed);
progressControl = CreateProgressControl();
progressControl.ShowProgress(longOperation);
longOperation.StartAsync();
OnOperationStarted();
}
protected abstract void DoWorkCore(LongOperation longOperation);
