Losing the Selection Focus
4/8/2010
When a Windows Classic Home screen plug-in loses focus, it receives a WM_TODAYCUSTOM_LOSTSELECTION message. Regardless of the value of the Selectability registry key, the plug-in also receives WM_ERASEBKGND and WM_PAINT messages so that it can redraw its content.
Note The plug-in must call InvalidateRect when it receives the WM_TODAYCUSTOM_LOSTSELECTION message to ensure that it will be refreshed correctly while scrolling.
WM_TODAYCUSTOM_LOSTSELECTION is defined as (WM_USER + 245). The parameters wParam and lParam are not used, and the return value is ignored. For example:
case WM_TODAYCUSTOM_LOSTSELECTION:
g_bSelected = FALSE;
break;