| Developing a User Interface > C1QueryFrame Control > Using C1QueryFrame Properties, Methods and Events > Events on Changing a Query Item |
Change event occurs after every change made by the end user in a C1QueryFrame control: field selection, comparison selection, value editing, and so on. There are also more specific change notification events:
When the end user opens a menu to change one of the elements of an item, or opens the control’s main menu, the BeforeMenu event is fired, giving the developer an opportunity to replace the default action (showing the menu), with another action (for example, showing a custom menu or a dialog).
When the end user selects an item from the menu, the MenuSelected event is fired, giving the developer an opportunity to override the default menu action.
When the end user selects an item from the menu, the AfterMenu event is fired, where the developer can perform some action after menu selection.
If you want to perform some actions before or after the user changes a constant value, use BeforeEdit and AfterEdit events.