System.Windows.Controls.AutoCompleteBox.OpeningDropDown C# (CSharp) Méthode

        private void OpeningDropDown(bool oldValue)
        {
#if SILVERLIGHT
            RoutedPropertyChangingEventArgs<bool> args = new RoutedPropertyChangingEventArgs<bool>(IsDropDownOpenProperty, oldValue, true, true);
#else
            RoutedPropertyChangingEventArgs<bool> args = new RoutedPropertyChangingEventArgs<bool>(IsDropDownOpenProperty, oldValue, true, true, DropDownOpeningEvent);
#endif
            // Opening
            OnDropDownOpening(args);

            if(args.Cancel)
            {
                _ignorePropertyChange = true;
                SetValue(IsDropDownOpenProperty, oldValue);
            }
            else
            {
                RaiseExpandCollapseAutomationEvent(oldValue, true);
                OpenDropDown(oldValue, true);
            }

            UpdateVisualState(true);
        }