c - Win32 (GDI) - 设置 STATIC 控件的不透明度

Question

我正在使用 C -(没有 MFC 或 GDI+) :-)

我想要的是将我的子窗口的不透明度设置为 100(我的子窗口是一个 STATIC 控件)。我想知道这是否可能，如果可以，请有人为我指出正确的操作方向。

这是我的设置:

我按如下方式创建我的父窗口:

HWND     hWnd;
WNDCLASS wndCls_s;


wndCls_s.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wndCls_s.lpfnWndProc   = MainWndProc;
wndCls_s.cbClsExtra    = 0;
wndCls_s.cbWndExtra    = 0;
wndCls_s.hInstance     = hInstance;
wndCls_s.hIcon         = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_BSN_64));
wndCls_s.hCursor       = LoadCursor(NULL, IDC_ARROW);
wndCls_s.hbrBackground = CreateSolidBrush(RGB(0, 0, 0));
wndCls_s.lpszMenuName  = NULL;
wndCls_s.lpszClassName = pszCName;

if (RegisterClass(&wndCls_s) == 0)
    return EXIT_FAILURE;


/* Creating Window */
hWnd = CreateWindow(
    pszCName, pszCName,
    WS_VISIBLE | WS_POPUP | WS_SYSMENU | WS_CLIPCHILDREN,
    0, 0, WND_WIDTH, WND_HEIGHT,
    NULL, NULL, hInstance, NULL);

在我的 MainWndProc 中:

case WM_CREATE: 
    {   
    HWND hWndChild = CreateWindow(
        L"STATIC", (LPCTSTR) NULL,
        WS_CHILD | WS_VISIBLE,
        10, 10, 110, 110,
        hWnd, (HMENU) (int) 10000, 
        g_hInst, NULL);
    }
    break;
case WM_CTLCOLORSTATIC:
    {
    COLORREF dwColor; 

    dwColor = RGB(255, 0, 0);
    hDC = (HDC) wParam;

    //SetBkColor(hDC, dwColor);
    SetBkMode(hDC, TRANSPARENT);

    /*
    This is not going to work for child window
    SetWindowLong(
        hWnd, GWL_EXSTYLE,
        GetWindowLong((HWND)lParam, GWL_EXSTYLE) & ~WS_EX_LAYERED);

        SetLayeredWindowAttributes(
            (HWND)lParam, 0, 100, LWA_ALPHA);
        RedrawWindow((HWND)lParam, NULL, NULL, RDW_ERASE | RDW_INVALIDATE);
    */

    if (g_hBrushRed == NULL)
        g_hBrushRed = CreateSolidBrush(dwColor);
    }
    return (INT_PTR)g_hBrushRed;

Answer 1

如果要为背景返回有效的画笔，为什么要使用 TRANSPARENT 启用透明度？您不需要 SetBkMode，然后控件将使用您的红色画笔。