InvalidOperationException: Cross-thread operation not valid: Control ‘Form1’ accessed from a thread other than the thread it was created on.

When I first time met with this error, it was caused by an update of a windows form control from a separate thread.Here is the workaround.// delegation to cross the thread boundaryprivate delegate void AddComboBoxItemDelegate(object item);private void AddComboBoxItem(object item){  if (this.comboBox1.InvokeRequired) {    // Invoke delegate so that the main UI thread is able to update the controls in the formthis.comboBox1.Invoke(new AddComboBoxItemDelegate(this.AddComboBoxItem), item);  }  else...