c++ - 无法更改背景颜色 MDI c++

Question

我正在写一个程序，我遇到了一个问题，希望你们能帮助我。

就像您在下面的代码中看到的那样，我有创建大型机(父窗口)的 WinMain WINAPI。当我尝试更改 wc.hbrBackground 变量中的背景颜色时，没有任何反应。我真的不明白为什么。我几乎尝试了一切。无论我选择哪种颜色，它都会保持深灰色背景 - 并且不会发生任何错误。我怀疑客户区的“标记”是问题所在，但我想不通。
你们能帮我看看怎么改吗？

我在 main.cpp 中的代码摘录:

HWND CreateNewMDIChild(HWND hMDIClient)
{
   MDICREATESTRUCT mcs;
   HWND hChild;

   mcs.szTitle = "[Untitled]";
   mcs.szClass = g_szChildClassName;
   mcs.hOwner  = GetModuleHandle(NULL);
   mcs.x = mcs.cx = CW_USEDEFAULT;
   mcs.y = mcs.cy = CW_USEDEFAULT;
   mcs.style = MDIS_ALLCHILDSTYLES;

   hChild = (HWND)SendMessage(hMDIClient, WM_MDICREATE, 0, (LONG)&mcs);
   if(!hChild)
   {
      MessageBox(hMDIClient, "MDI Child creation failed.", "Oh Oh...",
        MB_ICONEXCLAMATION | MB_OK);
   }
   return hChild;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
   switch(msg)
   {
        case WM_CREATE:
        {                       
             HWND hStatus;
             int statwidths[] = {100, -1};

             CLIENTCREATESTRUCT ccs;

             // Create MDI Client

             // Find window menu where children will be listed
             ccs.hWindowMenu  = GetSubMenu(GetMenu(hwnd), 5);
             ccs.idFirstChild = ID_MDI_FIRSTCHILD;

             g_hMDIClient = CreateWindowEx(WS_EX_CLIENTEDGE, "mdiclient", NULL,
                 WS_CHILD | WS_CLIPCHILDREN | WS_VSCROLL | WS_HSCROLL | WS_VISIBLE,
                 CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
                 hwnd, (HMENU)IDC_MAIN_MDI, GetModuleHandle(NULL), (LPVOID)&ccs);

             if(g_hMDIClient == NULL)
                  MessageBox(hwnd, "Could not create MDI client.", "Error", MB_OK | MB_ICONERROR);

             // Create Toolbar

             HWND hTool;
             TBBUTTON tbb[5];
             TBADDBITMAP tbab;

             hTool = CreateWindowEx(0, TOOLBARCLASSNAME, NULL, WS_CHILD | WS_VISIBLE, 0, 0, 0, 0,
                    hwnd, (HMENU)IDC_MAIN_TOOL, GetModuleHandle(NULL), NULL);
             if(hTool == NULL)
                   MessageBox(hwnd, "Could not create tool bar.", "Error", MB_OK | MB_ICONERROR);

             // Send the TB_BUTTONSTRUCTSIZE message, which is required for
             // backward compatibility.
             SendMessage(hTool, TB_BUTTONSTRUCTSIZE, (WPARAM)sizeof(TBBUTTON), 0);

             tbab.hInst = HINST_COMMCTRL;
             tbab.nID = IDB_STD_SMALL_COLOR;
             SendMessage(hTool, TB_ADDBITMAP, 0, (LPARAM)&tbab);

             ZeroMemory(tbb, sizeof(tbb));
             tbb[0].iBitmap = STD_FILENEW;
             tbb[0].fsState = TBSTATE_ENABLED;
             tbb[0].fsStyle = TBSTYLE_BUTTON;
             tbb[0].idCommand = ID_FILE_NEW;


            SendMessage(hTool, TB_ADDBUTTONS, sizeof(tbb)/sizeof(TBBUTTON), (LPARAM)&tbb);

            // Create Status bar

           hStatus = CreateWindowEx(0, STATUSCLASSNAME, NULL,
                   WS_CHILD | WS_VISIBLE | SBARS_SIZEGRIP, 0, 0, 0, 0,
                   hwnd, (HMENU)IDC_MAIN_STATUS, GetModuleHandle(NULL), NULL);

           SendMessage(hStatus, SB_SETPARTS, sizeof(statwidths)/sizeof(int), (LPARAM)statwidths);
           SendMessage(hStatus, SB_SETTEXT, 0, (LPARAM)"Version 1.0.0 beta");

    }
    break;
    case WM_SIZE:
    {
        HWND hTool;
        RECT rcTool;
        int iToolHeight;

        HWND hStatus;
        RECT rcStatus;
        int iStatusHeight;

        HWND hMDI;
        int iMDIHeight;
        RECT rcClient;

        // Size toolbar and get height

        hTool = GetDlgItem(hwnd, IDC_MAIN_TOOL);
        SendMessage(hTool, TB_AUTOSIZE, 0, 0);

        GetWindowRect(hTool, &rcTool);
        iToolHeight = rcTool.bottom - rcTool.top;

        // Size status bar and get height

        hStatus = GetDlgItem(hwnd, IDC_MAIN_STATUS);
        SendMessage(hStatus, WM_SIZE, 0, 0);

        GetWindowRect(hStatus, &rcStatus);
        iStatusHeight = rcStatus.bottom - rcStatus.top;

        // Calculate remaining height and size edit

        GetClientRect(hwnd, &rcClient);

        iMDIHeight = rcClient.bottom - iToolHeight - iStatusHeight;

        hMDI = GetDlgItem(hwnd, IDC_MAIN_MDI);
        SetWindowPos(hMDI, NULL, 0, iToolHeight, rcClient.right, iMDIHeight, SWP_NOZORDER); 
    }
    break;
    case WM_CLOSE:
        DestroyWindow(hwnd);
    break;
    case WM_DESTROY:
        PostQuitMessage(0);
    break;
    case WM_COMMAND:
        // Some code
    default:
        return DefFrameProc(hwnd, g_hMDIClient, msg, wParam, lParam);
}
return 0;
}

LRESULT CALLBACK MDIChildWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
    case WM_CREATE:
    {
                CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER | WS_TABSTOP | WS_GROUP, 270, 40, 80, 20, hwnd, (HMENU) ID_EB_1, NULL, NULL);
            CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER | WS_TABSTOP, 270, 70, 80, 20, hwnd, (HMENU) ID_EB_2, NULL, NULL);
            CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER | WS_TABSTOP, 430, 70, 80, 20, hwnd, (HMENU) ID_EB_3, NULL, NULL);

            CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER | WS_TABSTOP, 270, 135, 80, 20, hwnd, (HMENU) ID_EB_4, NULL, NULL);
            CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER | WS_TABSTOP, 430, 135, 80, 20, hwnd, (HMENU) ID_EB_5, NULL, NULL);
    }
    break;
    case WM_COMMAND:
                 // Some code
    break;
    return DefMDIChildProc(hwnd, msg, wParam, lParam);
    default:
        return DefMDIChildProc(hwnd, msg, wParam, lParam);

}
return 0;
}

BOOL SetUpMDIChildWindowClass(HINSTANCE hInstance)
{
WNDCLASSEX wc;

wc.cbSize        = sizeof(WNDCLASSEX);
wc.style         = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc   = MDIChildWndProc;
wc.cbClsExtra    = 0;
wc.cbWndExtra    = 0;
wc.hInstance     = hInstance;
wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_3DFACE+1);
wc.lpszMenuName  = NULL;
wc.lpszClassName = g_szChildClassName;
wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

if(!RegisterClassEx(&wc))
{
    MessageBox(0, "Could Not Register Child Window", "Oh Oh...",
        MB_ICONEXCLAMATION | MB_OK);
    return FALSE;
}
else
    return TRUE;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;

InitCommonControls();

wc.cbSize        = sizeof(WNDCLASSEX);
wc.style         = 0;
wc.lpfnWndProc   = WndProc;
wc.cbClsExtra    = 0;
wc.cbWndExtra    = 0;
wc.hInstance     = hInstance;
wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName  = MAKEINTRESOURCE(IDR_MAINMENU);
wc.lpszClassName = g_szClassName;
wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

if(!RegisterClassEx(&wc))
{
    MessageBox(NULL, "Window Registration Failed!", "Error!",
        MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

if(!SetUpMDIChildWindowClass(hInstance))
    return 0;

hwnd = CreateWindowEx(
    0,
    g_szClassName,
    "Conosoft Enomi - Version 1.0.0 (beta)",
    WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN,
    CW_USEDEFAULT, CW_USEDEFAULT, 1100, 700,
    NULL, NULL, hInstance, NULL);

if(hwnd == NULL)
{
    MessageBox(NULL, "Window Creation Failed!", "Error!",
        MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

g_hMainWindow = hwnd;

ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);

while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
        if (!TranslateMDISysAccel(g_hMDIClient, &Msg))
        {
            TranslateMessage(&Msg);
            DispatchMessage(&Msg);
        }
}
return Msg.wParam;
}

希望大家帮帮我，谢谢! :)

Answer 1

您不能使用hbrBackground 影响此更改，因为客户端窗口类是由系统预定义的。当您创建客户端窗口时，您将 "mdiclient" 作为窗口类名传递。您没有注册该类，它是预定义的。顺便说一下，您应该使用宏 MDICLIENT 来指定该类名。

相反，您需要子类化客户端窗口并处理 WM_ERASEBKGND 以根据需要绘制背景。