Declarationproperty OnSelectionChanging: TIESelectionChangingEvent;
Occurs prior to a change in the selected frame/thumbnail due to user action (i.e. mouse or keyboard).
This can be used to prevent changing of a selection (e.g. due to the current selection not being saved).OnSelectionChanging
occurs during the selection process, whereas OnSelectionChanged
occurs after the change (so the selection index and count will be valid).
Exampleprocedure TfMain.ImageEnMView1SelectionChanging(Sender: TObject; NewIndex: Integer; var Allow: Boolean);
// Don't allow changing of the selection if the user cancels saving of the selected image
if fSelectedImageChanged and (PromptToSaveSelectedImageChanges() = False) then
Allow := False;