WM_DRAWITEM (in Value Set Controls) - Syntax

This notification message is sent to the owner of a value set control each time an item that has the VIA_OWNERDRAW attribute is to be drawn, or when the background of a value set window that has the VS_OWNERDRAW style bit is to be drawn.

param1
     USHORT      id          /*  Window identifier. */

param2
     POWNERITEM  powneritem  /*  Pointer to an OWNERITEM data structure. */