程序代码：

//初始化
BOOL Game_Init(HWND hwnd)
{
    g_hdc = GetDC(hwnd);
    g_hBackGround = (HBITMAP)LoadImage(NULL, L"bg.bmp", IMAGE_BITMAP, WINDOW_WIDTH, WINDOW_HEIGHT, LR_LOADFROMFILE);
    g_hSprite1 = (HBITMAP)LoadImage(NULL, L"character1.bmp", IMAGE_BITMAP, 535, 650, LR_LOADFROMFILE);
    g_hSprite2 = (HBITMAP)LoadImage(NULL, L"character2.bmp", IMAGE_BITMAP, 506, 650, LR_LOADFROMFILE);
    g_mdc = CreateCompatibleDC(g_hdc);
    Game_Paint(hwnd);
    ReleaseDC(hwnd, g_hdc);
    return TRUE;
}

//在函数中进行绘制操作
VOID Game_Paint(HWND hwnd)
{
    SelectObject(g_mdc, g_hBackGround);
    BitBlt(g_hdc, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, g_mdc, 0, 0, SRCCOPY);
    SelectObject(g_mdc, g_hSprite1);
    TransparentBlt(g_hdc, 0, WINDOW_HEIGHT - 650, 535, 650, g_mdc, 0, 0, 535, 650, RGB(0, 0, 0));//设置RGB(0, 0, 0)为透明色
    
    SelectObject(g_mdc, g_hSprite2);
    TransparentBlt(g_hdc, 500, WINDOW_HEIGHT - 650, 506, 650, g_mdc, 0, 0, 506, 650, RGB(0, 0, 0));
}

//资源清理函数
BOOL Game_CleanUp(HWND hwnd)
{
    DeleteObject(g_hBackGround);
    DeleteObject(g_hSprite1);
    DeleteObject(g_hSprite2);
    DeleteDC(g_mdc);
    return TRUE;
}