public void UpdateMainIcon( Icon icon )
{
// TDM_UPDATE_ICON = WM_USER+116 // wParam = icon element (TASKDIALOG_ICON_ELEMENTS), lParam = new icon (hIcon if TDF_USE_HICON_* was set, PCWSTR otherwise)
NativeMethods.SendMessage (
this.handle,
(uint)NativeMethods.TASKDIALOG_MESSAGES.TDM_UPDATE_ICON,
(IntPtr)NativeMethods.TASKDIALOG_ICON_ELEMENTS.TDIE_ICON_MAIN,
( icon == null ? IntPtr.Zero : icon.Handle ) );
}