ich hab den Code hier mal hier im Forum gesehen:

void DrawTransparentBitmap(HDC hdc, HBITMAP hBitmap, short xStart, short yStart, COLORREF cTransparentColor)
{
	BITMAP     bm;
	COLORREF   cColor;
	HBITMAP    bmAndBack, bmAndObject, bmAndMem, bmSave;
	HBITMAP    bmBackOld, bmObjectOld, bmMemOld, bmSaveOld;
	HDC        hdcMem, hdcBack, hdcObject, hdcTemp, hdcSave;
	POINT      ptSize;

	hdcTemp = CreateCompatibleDC(hdc);
	SelectObject(hdcTemp, hBitmap);   // Select the bitmap

	GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm);
	ptSize.x = bm.bmWidth;        // Get width of bitmap
	ptSize.y = bm.bmHeight;       // Get height of bitmap
	DPtoLP(hdcTemp, &ptSize, 1);  // Convert from device
							// to logical points

	// Create some DCs to hold temporary data.
	hdcBack   = CreateCompatibleDC(hdc);
	hdcObject = CreateCompatibleDC(hdc);
	hdcMem    = CreateCompatibleDC(hdc);
	hdcSave   = CreateCompatibleDC(hdc);

	// Create a bitmap for each DC. DCs are required for a number of
	// GDI functions.

	// Monochrome DC
	bmAndBack   = CreateBitmap(ptSize.x, ptSize.y, 1, 1, NULL);

	// Monochrome DC
	bmAndObject = CreateBitmap(ptSize.x, ptSize.y, 1, 1, NULL);

	bmAndMem    = CreateCompatibleBitmap(hdc, ptSize.x, ptSize.y);
	bmSave      = CreateCompatibleBitmap(hdc, ptSize.x, ptSize.y);

	// Each DC must select a bitmap object to store pixel data.
	bmBackOld   = static_cast<HBITMAP>(SelectObject(hdcBack, bmAndBack));
	bmObjectOld = static_cast<HBITMAP>(SelectObject(hdcObject, bmAndObject));
	bmMemOld    = static_cast<HBITMAP>(SelectObject(hdcMem, bmAndMem));
	bmSaveOld   = static_cast<HBITMAP>(SelectObject(hdcSave, bmSave));

	// Set proper mapping mode.
	SetMapMode(hdcTemp, GetMapMode(hdc));

	// Save the bitmap sent here, because it will be overwritten.
	BitBlt(hdcSave, 0, 0, ptSize.x, ptSize.y, hdcTemp, 0, 0, SRCCOPY);

	// Set the background color of the source DC to the color.
	// contained in the parts of the bitmap that should be transparent
	cColor = SetBkColor(hdcTemp, cTransparentColor);

	// Create the object mask for the bitmap by performing a BitBlt
	// from the source bitmap to a monochrome bitmap.
	BitBlt(hdcObject, 0, 0, ptSize.x, ptSize.y, hdcTemp, 0, 0,
		SRCCOPY);

	// Set the background color of the source DC back to the original
	// color.
	SetBkColor(hdcTemp, cColor);

	// Create the inverse of the object mask.
	BitBlt(hdcBack, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0,
		NOTSRCCOPY);

	// Copy the background of the main DC to the destination.
	BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdc, xStart, yStart,
		SRCCOPY);

	// Mask out the places where the bitmap will be placed.
	BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0, SRCAND);

	// Mask out the transparent colored pixels on the bitmap.
	BitBlt(hdcTemp, 0, 0, ptSize.x, ptSize.y, hdcBack, 0, 0, SRCAND);

	// XOR the bitmap with the background on the destination DC.
	BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcTemp, 0, 0, SRCPAINT);

	// Copy the destination to the screen.
	BitBlt(hdc, xStart, yStart, ptSize.x, ptSize.y, hdcMem, 0, 0,
		SRCCOPY);

	// Place the original bitmap back into the bitmap sent here.
	BitBlt(hdcTemp, 0, 0, ptSize.x, ptSize.y, hdcSave, 0, 0, SRCCOPY);

	// Delete the memory bitmaps.
	DeleteObject(SelectObject(hdcBack, bmBackOld));
	DeleteObject(SelectObject(hdcObject, bmObjectOld));
	DeleteObject(SelectObject(hdcMem, bmMemOld));
	DeleteObject(SelectObject(hdcSave, bmSaveOld));

	// Delete the memory DCs.
	DeleteDC(hdcMem);
	DeleteDC(hdcBack);
	DeleteDC(hdcObject);
	DeleteDC(hdcSave);
	DeleteDC(hdcTemp);
}

leider werden bei mir nur schwarze Rechtecke gezeichnet!!!

Muss ich noch was machen ausser die Funktion aufrufen?

Hab ne Klasse dafür... und die Werte sind beim Aufruf der Funktion gefüllt...

class CGButton
{
private:
	HDC				hdcButton;
	HWND				hwnd;
	HBITMAP			hBitmap;
	HINSTANCE			hInstance;

	[...]
public:
	CGButton(HWND HWnd, HINSTANCE HInstance, int iWM_MessageCode, int PICTURE_1, int iXPosition, int iYPosition, int iHeight, int iWidth);
	~CGButton();
	void			SetButtonPics(int PICTURE);

	void			PaintButton();
	void			PaintButton(HDC hdc);
	[...]
};

//****SetButtonPics()****//
//Zum setzen der Bilder und zum ändern der Position und Größe
void CGButton::SetButtonPics(int PICTURE)
{
	HDC		hdc;

	hdc = GetDC(hwnd);

	hBitmap = (HBITMAP)LoadImage(hInstance,MAKEINTRESOURCE(PICTURE),IMAGE_BITMAP,0,0,LR_CREATEDIBSECTION);

	hdcButton = CreateCompatibleDC(hdc);
	SelectObject(hdcButton, hBitmap);

	DeleteObject(hBitmap);
	ReleaseDC(hwnd,hdc);
}

//****PaintButton()****//
//Zum Zeichnen des Buttons
void CGButton::PaintButton(HDC hdc)
{
	if (Visible == TRUE)
	{
		DrawTransparentBitmap(hdc, hBitmap, sSize.XPosition, sSize.YPosition, Color);
		if (PaintStatus == BUTTON_2)
		{
			HPEN		hPen, hOldPen;

			hPen = CreatePen (PS_SOLID, 1, GetSysColor(COLOR_APPWORKSPACE));
			hOldPen = (HPEN) SelectObject(hdc, hPen);

			MoveToEx(hdc,sSize.XPosition, sSize.YPosition, NULL);
			LineTo(hdc, sSize.XPosition + sSize.Width - 1, sSize.YPosition);
			LineTo(hdc, sSize.XPosition + sSize.Width - 1, sSize.YPosition + sSize.Height  - 1);
			LineTo(hdc, sSize.XPosition, sSize.YPosition + sSize.Height  - 1);
			LineTo(hdc, sSize.XPosition, sSize.YPosition);

			DeleteObject(SelectObject(hdc, hOldPen));
		}
	}
}

//****PaintButton()****//
//Zum Zeichnen des Buttons
void CGButton::PaintButton()
{
	HDC		hdc;

	if (Visible == TRUE)
	{
		hdc = GetDC(hwnd);
		PaintButton(hdc);
		ReleaseDC(hwnd,hdc);
	}
}

DeleteObject(hBitmap);

=> stimmt das passt nicht. ich probier das mal aus, dann meld ich mich nochmal

Warum setzt du eigentlich hBitmap in einen Geräte Kontext ein, den du niemals verwendest? DrawTranspar... setzt das Bitmap ja auch in einen DC ein, bzw. versucht es, aber ich glaube es schafft es nicht, weil das Bitmap schon in einem anderen DC selektiert ist.

mh... das hab ich nicht gewusst...

Sorry, das hab ich echt nicht gewusst

Danke!!!

Ansonsten gerne...