[RESOLVED] A little help! WM_PAINT + BMP

[v_nom70]

Hiho,

I just want to put a background image in my app, apparently works well but not, after a few clicks to resize it, my pc slow down, and I do not see the problem or may be my code wrong...accept help and suggestions! && light my way!

	//Warnings 0 
	//GetLastError No Error
	RECT rc;
	GetClientRect (wp_hwnd, &rc);
	HDC hdc_dst = GetDC (wp_hwnd);
	HDC hdc_src = CreateCompatibleDC (hdc_dst);
	HBITMAP bg_image = LoadBitmap (GetModuleHandle(NULL), MAKEINTRESOURCE (IDM_BGBMP)); 
	BITMAP bm;
	PAINTSTRUCT ps;


	switch (wp_msg)
	{
	case WM_PAINT:
		BeginPaint (wp_hwnd, &ps);
		GetObject (bg_image, sizeof (bm), &bm);
		SelectObject (hdc_src, bg_image);
		StretchBlt (
			hdc_dst,
			0,0,
			rc.right, rc.bottom,
			hdc_src,
			0, 0, 
			bm.bmWidth, bm.bmHeight,
			SRCCOPY);

		DeleteObject (&bg_image);
		ReleaseDC (wp_hwnd, hdc_dst);
		DeleteDC (hdc_src);
		DeleteObject (&bm);
        EndPaint(wp_hwnd, &ps);
		break;

	case WM_SIZE:
		SendMessage (wp_hwnd,WM_PAINT,0,0);
		break;

[Paul McKenzie]

Hiho,

I just want to put a background image in my app, apparently works well but not, after a few clicks to resize it, my pc slow down, and I do not see the problem or may be my code wrong...accept help and suggestions! && light my way!

You should really check your return values for those functions you're calling. You're just assuming they work without seeing if any of them return an error.

DeleteObject (&bg_image);

Why are you passing the address of an HBITMAP to DeleteObject?

http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx

If you checked the return value of DeleteObject, does it return 0 or non-zero? If it is zero, then you would have discovered the problem is with this function.

Regards,

Paul McKenzie

[Igor Vartanov]

BITMAP is just a structure intended to get bitmap info. This is not a GDI object, so DeleteObject(&bm) makes no sense. The deleted object should be HBITMAP bg_image. But with this you have another problem: you never unselect it prior to deleting hdc_src. However you must do that:

HBITMAP hbmOld = SelectObject(hdc_src, bg_image);
. . .
SelectObject(hdc_src, hbmOld); // unselecting bg_image 
// now you're allowed to delete
DeleteObject(bg_image);
DeleteDC(hdc_src);

[v_nom70]

mmm ok's im testing now... thanks guys.

[VladimirF]

Do you really need to load your image in response to EVERY windows message you get? (hint – no, you don’t).
Since you only attempt to delete this HBITMAP while processing WM_PAINT message, all other ones are leaking.

[VictorN]

2 OP:
You should not (must not!) send WM_PAINT message (in response on the WM_SIZE)
Instead you should (if you really need to) call InvalidateRect which will cause Windows to send WM_PAINT message to your window.