Winapi，改变groupbox框架的颜色

Question

我想使用WinAPI制作黑色半透明GUI。我做了一个自定义按钮，但我不能创建自己的组合框。在WM_DRAWITEM消息处理程序的情况下，甚至没有调用绘制我的groupbox的回调。这个回调包含甚至没有出现的MessageBox调用。

如何使用彩色框和彩色文字绘制组合框？另外，我想让我的分组框位于所有其他控件之下。怎么做？

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // Main logic goes here...
    ShowMainWindow();
}

void RegisterWndClass(WNDPROC Proc, LPCTSTR szName, UINT brBackground)
{
    WNDCLASSEX wc;

    wc.cbSize = sizeof(wc);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = Proc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = GetModuleHandle(NULL);
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = CreateSolidBrush(RGB(0x14, 0x14, 0x14));
    wc.lpszMenuName = NULL;
    wc.lpszClassName = szName;
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassEx(&wc))
    {
        MessageBox(NULL, TEXT("Cannot register class"), TEXT("Error"), MB_OK);
    }
}

// Draw custom button
void DrawButton(DRAWITEMSTRUCT *Item, HWND hwnd)
{

    SelectObject(Item->hDC, CreateFont(16, 0, 0, 0, FW_NORMAL, 0, 0, 0, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH, "Arial Black"));
    FillRect(Item->hDC, &Item->rcItem, CreateSolidBrush(RGB(0x14, 0x14, 0x14)));
    SelectObject(Item->hDC, CreateSolidBrush(0));
    if (Item->itemState & ODS_SELECTED)
    {
        SetTextColor(Item->hDC, 0);
        SelectObject(Item->hDC, CreateSolidBrush(0xFF00));
        SelectObject(Item->hDC, CreatePen(PS_SOLID, 2, 0xFF00));
    }
    else
    {
        SetTextColor(Item->hDC, 0x00FF00);
        SelectObject(Item->hDC, CreatePen(PS_SOLID, 2, 0x00FF00));

    }
    SetBkMode(Item->hDC, TRANSPARENT);
    RoundRect(Item->hDC, Item->rcItem.left, Item->rcItem.top, Item->rcItem.right, Item->rcItem.bottom, 20, 20);
    int len = GetWindowTextLength(Item->hwndItem);
    LPSTR lpBuff[255];
    GetWindowTextA(Item->hwndItem, lpBuff, len + 1);
    DrawTextA(Item->hDC, lpBuff, len, &Item->rcItem, DT_CENTER);
}

// Trying to draw customgroupbox
void DrawKeyGroup(DRAWITEMSTRUCT *Item, HWND hwnd)
{
    SelectObject(Item->hDC, CreateSolidBrush(RGB(0, 255, 0)));
    SelectObject(Item->hDC, CreateSolidBrush(0));

    SetTextColor(Item->hDC, 0x00FF00);
    SelectObject(Item->hDC, CreatePen(PS_SOLID, 2, 0x00FF00));
    MessageBox(NULL, "", "", MB_OK);

    //SetBkMode(Item->hDC, TRANSPARENT);
    RoundRect(Item->hDC, Item->rcItem.left, Item->rcItem.top, Item->rcItem.right, Item->rcItem.bottom, 200, 200);
}

//Main windows proc
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hDC;
    PAINTSTRUCT ps;
    RECT rect;

    switch (uMsg)
    {
    case WM_CREATE: // Init interface
        // Text field
        CreateWindow(TEXT("EDIT"),
            NULL,
            WS_VISIBLE | WS_CHILD | ES_LEFT | ES_AUTOHSCROLL,
            10, 280, 350, 20,
            hWnd,
            (HMENU)ID_KEY_FIELD,
            NULL,
            NULL);
        // Button to enter the text
        CreateWindowEx(0, TEXT("BUTTON"),
            TEXT("Unlock"),
            WS_VISIBLE | WS_CHILD | BS_OWNERDRAW,
            370, 280, 150, 20,
            hWnd,
            (HMENU)ID_KEY_ENTER,
            GetModuleHandle(NULL),
            NULL);
        // Groupbox
        CreateWindowEx(0, TEXT("BUTTON"),
            TEXT("Key"),
            WS_VISIBLE | WS_CHILD | BS_GROUPBOX | BS_OWNERDRAW,
            5, 262, 523, 47,
            hWnd,
            (HMENU)ID_KEY_GROUP,
            GetModuleHandle(NULL), 
            NULL);
        break;
    case WM_PAINT:
        hDC = BeginPaint(hWnd, &ps);
        GetClientRect(hWnd, &rect);
        EndPaint(hWnd, &ps);
        break;
    // Color text field
    case WM_CTLCOLOREDIT:
    {
        HDC hdc = (HDC)wParam;
        HWND hwnd = (HWND)lParam;
        if (GetDlgCtrlID(hwnd) == ID_KEY_FIELD)
        {
            SetTextColor(hdc, 0xFF00);
            SetBkColor(hdc, RGB(0x29, 0x29, 0x29));
            return (LRESULT)CreateSolidBrush(RGB(0x29, 0x29, 0x29));
        }
        break;
    }
    // Color statie elements (group box caption)
    /*case WM_CTLCOLORSTATIC:
        SetTextColor((HDC)wParam, RGB(0x00, 0x8C, 0xBA));

        SetBkMode((HDC)wParam, TRANSPARENT);
        SetBkColor((HDC)wParam, RGB(0x14, 0x14, 0x14));

        return (LRESULT)CreateSolidBrush(GetBkColor((HDC)wParam));*/
    // Draw custom controls
    case WM_DRAWITEM:
    {
        DRAWITEMSTRUCT *dis = (DRAWITEMSTRUCT*)lParam;
        switch (dis->CtlID)
        {
        case ID_KEY_ENTER:
            DrawButton(dis, GetDlgItem(hWnd, dis->CtlID));
            break;
        case ID_KEY_GROUP:
            DrawKeyGroup(dis, GetDlgItem(hWnd, dis->CtlID));
            break;
        }
    }
    case WM_SIZE:
        break;
    case WM_CLOSE:
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

void ShowMainWindow(void)
{
    HWND hMainWnd;
    MSG msg;

    RegisterWndClass(WndProc, TEXT("Info"), COLOR_WINDOW);

    hMainWnd = CreateWindowEx(WS_EX_LAYERED, TEXT("Info"), TEXT("Info"),
        WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX,
        CW_USEDEFAULT, 0, 550, 360, (HWND)NULL, (HMENU)NULL,
        GetModuleHandle(NULL), NULL);
    SetWindowLong(hMainWnd, GWL_EXSTYLE, GetWindowLong(hMainWnd, GWL_EXSTYLE) | WS_EX_LAYERED);
    SetLayeredWindowAttributes(hMainWnd, 0, (255 * 70) / 100, LWA_ALPHA);

    if (!hMainWnd)
    {
        MessageBox(NULL, TEXT("Can\'t create main window."), TEXT("Error"), MB_OK);
        return;
    }

    ShowWindow(hMainWnd, SW_SHOW);

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