BCGCBPRODLLEXPORT UINT BCGM_ON_BEFORE_SHOW_UNDO_ACTIONS_LIST

The message is sent to the main application frame before displaying the undo button's drop-down list.

Add the BCGM_ON_BEFORE_SHOW_UNDO_ACTIONS_LIST registered message handler to the toolbar owner class (e.g., CMainFrame) and populate the drop-down list by calling the CBCGPToolbarUndoButton::AddUndoAction method.

Parameters

wParam	contains the toolbar undo button command ID.
lParam	a pointer to the CBCGPToolbarUndoButton object.

Returns

non-zero to prevent the undo button's drop-down list from displaying.