c++ - Win32 选项卡控件灰色背景

Question

我正在努力使我在 win32 中的 ui 无处不在。问题是我的选项卡控件的背景不是白色的，所以不是选项卡本身，而是选项卡旁边的部分是灰色的。

我正在为静态控件处理 WM_CTLCOLORSTATIC，但它似乎不适用于选项卡控件。

case WM_CTLCOLORSTATIC:
{
                          HDC hEdit = (HDC)w_param;
                          SetBkMode(hEdit, TRANSPARENT);
                          SetTextColor(hEdit, RGB(0, 0, 0));
                          SetBkColor(hEdit, RGB(255, 255, 255));
                          // Do not return a brush created by CreateSolidBrush(...) because you'll get a memory leak
                          return (INT_PTR)GetStockObject(WHITE_BRUSH);
}

我希望有一种“简单”的方法可以让我的整个用户界面变白:)

加油

Answer 1

您不能在灰色背景上绘制消息。系统绘制WM_PRINTCLIENT 中的所有内容。然而，有一个很好的技巧!思路来自this post .

I do this (in my WM_PAINT handler):

1. Create a memory DC to draw into

2. Send a WM_PRINTCLIENT message to the tab control to get it to draw the tabs into your memory DC

3. Create a region which mirrors the shape of the tabs

4. Fill the parts of the memory DC outside this region (RGN_DIFF) with the desired background brush

5. Blt the result into the DC returned by BeginPaint

6. Call EndPaint and return, without calling the tab control's own WndProc of course :)

Step 3 is a bit fiddly as you have to know the location and shape of the tabs, but other than that it's a pretty clean solution (see image below the following sample code). You could probably use TransparentBlt to replace the system background colour instead.

我在此解决方案中使用 TransparentBlt:

创建hdcMemTab，第 1 步

HBITMAP hBitmap, hBitmapOld ; //keep them till the end of the program
HDC hdcMemTab; //keep it till the end of the program

HDC hdc;
Rect rt;
hdc = CreateIC(TEXT("DISPLAY"), NULL, NULL, NULL);
hdcMemTab = CreateCompatibleDC(hdc);
GetWindowRect(hwnd_Tab, &rt);

rt.right  = rt.right - rt.left;
rt.bottom = rt.bottom - rt.top;
rt.left   = 0; 
rt.top    = 0;

hBitmap = CreateCompatibleBitmap(hdc, rt.right, rt.bottom);
hBitmapOld = SelectObject(hdcMemTab, hBitmap);
DeleteDC(hdc);

在子类选项卡控件的 WM_PAINT 中:

RECT rt, rtTab;
HDC hdc = BeginPaint(hwnd, &ps);

GetWindowRect(hwnd_Tab, &rt);

rt.right  = rt.right - rt.left;
rt.bottom = rt.bottom - rt.top;
rt.left   = 0; 
rt.top    = 0;

//step 2
SendMessage(hwnd_Tab, WM_PRINTCLIENT, (WPARAM)hdcMemTab, PRF_CLIENT);

FillRect(hdc, &rt, gBrushWhite); //gBrushWhite has the desired background color

HRGN hRgn = CreateRectRgn(0, 0, 0, 0);

int n_items = TabCtrl_GetItemCount(hwnd_Tab);

//get tabs region, step 3
for(i = 0; i < n_items; i++){
    TabCtrl_GetItemRect(hwnd_Tab, i, &rtTab);

    HRGN hTabRgn = CreateRectRgn(rtTab.left, rtTab.top, rtTab.right, rt.bottom);

    CombineRgn(hRgn, hRgn, hTabRgn, RGN_OR);

    DeleteObject(hTabRgn);
}

GetRgnBox(hRgn, &rtTab);

DeleteObject(hRgn);

//step 5
TransparentBlt(hdc, 0, 0, rt.right, rt.bottom, hdcMemTab, 0, 0, rt.right, rt.bottom, RGB(240, 240, 240)); //(240, 240, 240) is the grey color
BitBlt(hdc, rtTab.left, rtTab.top, rtTab.right - 5, rtTab.bottom, hdcMemTab, rtTab.left, rtTab.top, SRCCOPY);

EndPaint(hwnd, &ps);

//step 6
return 0;