On_Select userexit in widget-menus/button-areas or On_Event userexit in widget-state.
After COPY DataView outputs a message regarding the number of records copied into the special DataView-clipboard. It is a pre-condition for a successful PASTE that source and target mask either point to the same database table or to tables that are related to each other. If this is not the case, DataView will output an error message.
Example:
In DataView itself the key-events [Ctrl+C] and [Ctrl+V] are realized for the Copy&Paste functions with this userexit.