Hello.
Though I set transparence color in CExtBitMap, bitmap does not become transparent.
Please teach a cause.

virtual void OnPaintButton(
const RECT & rcButton,
INT nButtonType, // e_button_type_t
bool bPressed,
bool bHovered,
bool bFocused,
bool bEnabled,
const CExtGridWnd & wndGrid,
CDC & dc,
LONG nVisibleColNo,
LONG nVisibleRowNo,
LONG nColNo,
LONG nRowNo,
INT nColType,
INT nRowType,
const RECT & rcCellExtra,
const RECT & rcCell,
const RECT & rcVisibleRange,
DWORD dwAreaFlags,
DWORD dwHelperPaintFlags
) const
{
ASSERT_VALID( this );
ASSERT_VALID( (&wndGrid) );
ASSERT( dc.GetSafeHdc() != NULL );
if( ! dc.RectVisible(&rcButton) )
return;
nVisibleColNo; nVisibleRowNo; nColNo; nRowNo; nColType; nRowType;
rcCellExtra; rcCell; rcVisibleRange; dwAreaFlags;
if( ! bEnabled )
bPressed = false;
if( (dwHelperPaintFlags&__EGCPF_SIMPLIFIED_RENDERING_TARGET) == 0 )
{
COLORREF clrFace = wndGrid.OnSiwGetSysColor( COLOR_3DFACE );
COLORREF clrLight = wndGrid.OnSiwGetSysColor( COLOR_3DHIGHLIGHT );
COLORREF clrShadow = CExtPaintManager::stat_HLS_Adjust( wndGrid.OnSiwGetSysColor( COLOR_3DSHADOW ) , 0.0, 0.35, 0.0 );
COLORREF clrWindow = wndGrid.OnSiwGetSysColor( COLOR_WINDOW );
COLORREF clrText = wndGrid.OnSiwGetSysColor( COLOR_BTNTEXT );
wndGrid.PmBridge_GetPM()->Grid_PaintButton(
dc, rcButton, nButtonType, bPressed, bHovered, bFocused, bEnabled,
clrFace, clrLight, clrShadow, clrWindow, clrText,
dwHelperPaintFlags, (CObject*) &wndGrid, 0L
);
if ( m_pEllipsis.IsEmpty() ){
m_pEllipsis.LoadBMP_Resource( MAKEINTRESOURCE( /*IDB_GRID_ICONS*/ IDB_KAKO_OUKA_SIGUTI_BTN ) );
m_pEllipsis.Make32();
m_pEllipsis.AlphaColor( RGB(255,0,255) , RGB(0,0,0), 0 );
}
CRect cRect = rcButton;
cRect.DeflateRect( 1 , 1 );
m_pEllipsis.Draw( dc.m_hDC , cRect );