C++ WINAPI setting window background image doesn't work - c++

Question

I hate that I have done it before, I feel like I am missing something and I don't know what it is. So, I am trying to set the background image of a windows in C++ WinAPI.
My Resources.rc
#include "Resources.h"
BACKGROUND BITMAP "background.bmp"
My Resources.h
#define BACKGROUND 200
My Main.cpp
....
WNDCLASSEX wcls;
wcls.cbSize = sizeof(WNDCLASSEX);
wcls.style = CS_PARENTDC|CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS;
wcls.lpfnWndProc = WndProc;
wcls.cbClsExtra = 0;
wcls.cbWndExtra = 0;
wcls.hInstance = hInstance;
wcls.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(HICON));
wcls.hCursor = LoadCursor(NULL, IDC_ARROW);
wcls.hbrBackground = HBRUSH(COLOR_WINDOW + 1);
wcls.lpszClassName = L"WndClass";
wcls.hIconSm = LoadIcon(hInstance, MAKEINTRESOURCE(HICON));
HWND Window = CreateWindowEx (
WS_EX_LAYERED|WS_EX_TOOLWINDOW,
wcls.lpszClassName,
L"Window Title",
WS_VISIBLE|WS_POPUP|WS_CLIPCHILDREN,
CW_USEDEFAULT,
CW_USEDEFAULT,
384,
128,
NULL,
NULL,
hInstance,
NULL
);
if (!Window ) return 0;
SetLayeredWindowAttributes(
Window,
RGB(35, 35, 35),
85,
LWA_ALPHA|LWA_COLORKEY
);
SetWindowPos(
Window,
HWND_TOPMOST,
0,
0,
0,
0,
SWP_NOMOVE|SWP_NOREDRAW|SWP_NOSIZE
);
ShowWindow(Window, SW_SHOWNORMAL);
UpdateWindow(Window);
LRESULT CALLBACK WndProc(HWND hWnd, UINT Msg, WPARAM Wpar, LPARAM Lpar) {
HBITMAP Background = NULL;
BITMAP BgImg;
HDC DeviceContext, BgContext;
PAINTSTRUCT PaintStruct;
switch (Msg) {
case WM_PAINT:
ContextLansator = BeginPaint(hWnd, &PaintStruct);
Fundal = LoadBitmap(hInstance, MAKEINTRESOURCE(BACKGROUND));
FundalLansator = CreateCompatibleDC(DeviceContext);
SelectObject(DeviceContext, Background);
GetObject(Background, sizeof(BgImg), &BgImg);
BitBlt(DeviceContext, 0, 0, 384, 128, BgContext, 0, 0, SRCAND);
DeleteObject(Background);
DeleteDC(BgContext);
EndPaint(hWnd, &PaintStruct);
break;
.....
I am using Code::Blocks. The resource is embedded correctly, the window starts but just a white background, the image is not painted. The WM_PAINT message is called once, at the beginning. I fill like something is wrong with BgImg but I don't know what. Some help needed! Thanks!

Answer 1

Create a PatternBrush and set it to the background before registering class. For example:
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_WINAPIBACKGROUND));
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = CreatePatternBrush(LoadBitmap( hInstance, MAKEINTRESOURCE( IDB_BITMAP1 ) ) );
wcex.lpszMenuName = MAKEINTRESOURCE(IDC_WINAPIBACKGROUND);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassEx(&wcex);
}
It looks like this:
Bitmap depth shouldn't matter. But take a look at the styles in your implementation.

Answer 2

i use this code and it work fine for me.
i use code block 4.7 too.
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc;
BITMAP bitmap;
HDC hdcMem;
HGDIOBJ oldBitmap;
hBitmap01 = (HBITMAP)LoadImage(NULL, "c:\\energy.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
hdc = BeginPaint(wnd01, &ps);
hdcMem = CreateCompatibleDC(hdc);
oldBitmap = SelectObject(hdcMem, hBitmap01);
GetObject(hBitmap01, sizeof(bitmap), &bitmap);
BitBlt(hdc, 0, 0, bitmap.bmWidth, bitmap.bmHeight, hdcMem, 0, 0, SRCCOPY);
SelectObject(hdcMem, oldBitmap);
DeleteDC(hdcMem);
EndPaint(wnd01, &ps);
}

Answer 3

After 20 hours working on what I think is a similar symptom, I found a solution.
My problem was bitmap not loading. I verified the file was truly bitmap and code correct. I corrected and recompiled but Code::Blocks would not load it (return = 0). Try deleting, the two folders BIN and OBJ and the two files xxx.depend and xxx.layout. Then recompile and run.