https://stackoverflow.com/questions/70248510/how-do-i-load-a-bitmap-into-a-win32-application

<code C++>
#ifndef UNICODE
#define UNICODE
#endif

#include <windows.h>
#include <iostream>

HANDLE hImg = NULL;

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    const wchar_t CLASS_NAME[] = L"Window Class";

    WNDCLASS wc = {};

    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.lpszClassName = CLASS_NAME;

    RegisterClass(&wc);

    HWND hwnd = CreateWindowEx(
        0,
        CLASS_NAME,
        L"My Application",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL
    );

    if (hwnd == NULL) {
        return 0;
    }

    ShowWindow(hwnd, nShowCmd);


    MSG msg = {};
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_CREATE:
        if (!hImg)
            hImg = LoadImage(NULL, L"c:\\zc\\test_image.bmp", IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
        if (!hImg) { DWORD err = GetLastError(); std::cout << err; }
        return 0;

    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hwnd, &ps);
        FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW + 1));

        if (hImg) {
            BITMAP bm;
            GetObject(hImg, sizeof(bm), &bm);//get bitmap dimension
            auto memdc = CreateCompatibleDC(hdc);
            auto oldbmp = SelectObject(memdc, (HBITMAP)hImg);
            BitBlt(hdc, 0, 0, bm.bmWidth, bm.bmHeight, memdc, 0, 0, SRCCOPY);
            SelectObject(memdc, oldbmp);//restore memdc
            DeleteDC(memdc);//delete memdc, we don't need it anymore
        }

        EndPaint(hwnd, &ps);
        return 0;
    }

    case WM_DESTROY:
        if (hImg) DeleteObject(hImg);//release resource
        hImg = NULL;
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

</code>


<code>
TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
CONFIG -= qt

LIBS += -lgdi32

SOURCES +=  main.cpp
</code>