The following code illustrates how to change graphical data for a graphic button.
typedef struct { USHORT usReserved; /*Reserved field */ PSZ pszText; /*Initial text of button */ HMODULE hmod; /*Module handle for bit maps */ USHORT cBitmaps; /*Number of bit maps */ USHORT aidBitmap[1]; /*Array of bit-map IDs */ }GBTNCDATA; typedef GBTNCDATA *PGBTNCDATA; GBTNCDATA cdata; cdata.usReserved = GB_STRUCTURE; cdata.pszText = "Play"; cdata.hmod = hmodBitmaps; cdata.cBitmaps = 1; cdata.aidBitmap[0] = ID_PLAY; WinSendMsg ( hwndButton, GBM_SETGRAPHICDATA, (MPARAM)&cdata, 0L;