使用 Win32 的带有主题的透明单选按钮控件

Question

我正在尝试在启用主题时仅使用 Win32 制作具有透明背景的单选按钮控件。这样做的原因是允许将单选按钮放置在图像上并显示图像（而不是灰色的默认控件背景）。

开箱即用的情况是，该控件将具有灰色的默认控件背景，并且通过处理 WM_CTLCOLORSTATIC 或 WM_CTLCOLORBTN 来更改此背景的标准方法（如下所示）不起作用：

case WM_CTLCOLORSTATIC:
    hdcStatic = (HDC)wParam;

    SetTextColor(hdcStatic, RGB(0,0,0)); 
    SetBkMode(hdcStatic,TRANSPARENT);

    return (LRESULT)GetStockObject(NULL_BRUSH);
    break;  

到目前为止，我的研究表明，所有者抽奖是实现这一目标的唯一方法。我已经成功地使用“所有者绘制”单选按钮实现了大部分功能 - 通过下面的代码，我有一个单选按钮和透明背景（背景在 WM_CTLCOLORBTN 中设置）。但是，使用此方法会切断无线电检查的边缘 - 我可以通过取消对函数 DrawThemeParentBackgroundEx 的调用的注释来恢复它们，但这会破坏透明度。

void DrawRadioControl(HWND hwnd, HTHEME hTheme, HDC dc, bool checked, RECT rcItem)
{
    if (hTheme)
    {
      static const int cb_size = 13;

      RECT bgRect, textRect;
      HFONT font = (HFONT)SendMessageW(hwnd, WM_GETFONT, 0, 0);
      WCHAR *text = L"Experiment";

      DWORD state = ((checked) ? RBS_CHECKEDNORMAL : RBS_UNCHECKEDNORMAL) | ((bMouseOverButton) ? RBS_HOT : 0); 

      GetClientRect(hwnd, &bgRect);
      GetThemeBackgroundContentRect(hTheme, dc, BP_RADIOBUTTON, state, &bgRect, &textRect);

      DWORD dtFlags = DT_VCENTER | DT_SINGLELINE;

      if (dtFlags & DT_SINGLELINE) /* Center the checkbox / radio button to the text. */
         bgRect.top = bgRect.top + (textRect.bottom - textRect.top - cb_size) / 2;

      /* adjust for the check/radio marker */
      bgRect.bottom = bgRect.top + cb_size;
      bgRect.right = bgRect.left + cb_size;
      textRect.left = bgRect.right + 6;

      //Uncommenting this line will fix the button corners but breaks transparency
      //DrawThemeParentBackgroundEx(hwnd, dc, DTPB_USECTLCOLORSTATIC, NULL);

      DrawThemeBackground(hTheme, dc, BP_RADIOBUTTON, state, &bgRect, NULL);
      if (text)
      {
          DrawThemeText(hTheme, dc, BP_RADIOBUTTON, state, text, lstrlenW(text), dtFlags, 0, &textRect);

      }

   }
   else
   {
       // Code for rendering the radio when themes are not present
   }

}

上面的方法是从 WM_DRAWITEM 调用的，如下所示：

case WM_DRAWITEM:
{
    LPDRAWITEMSTRUCT pDIS = (LPDRAWITEMSTRUCT)lParam;
    hTheme = OpenThemeData(hDlg, L"BUTTON");    

    HDC dc = pDIS->hDC;

    wchar_t sCaption[100];
    GetWindowText(GetDlgItem(hDlg, pDIS->CtlID), sCaption, 100);
    std::wstring staticText(sCaption);

    DrawRadioControl(pDIS->hwndItem, hTheme, dc, radio_group.IsButtonChecked(pDIS->CtlID), pDIS->rcItem, staticText);                               

    SetBkMode(dc, TRANSPARENT);
    SetTextColor(hdcStatic, RGB(0,0,0));                                
    return TRUE;

}                           

所以我的问题是我想的两个部分：

1. 我是否错过了其他一些方法来实现我想要的结果？
2. 是否可以用我的代码修复按钮剪角问题并且仍然具有透明背景

Answer 1

经过近三个月的断断续续的研究，我终于找到了一个令我满意的解决方案。我最终发现，由于某种原因，单选按钮边缘没有被 WM_DRAWITEM 中的例程绘制，但是如果我使单选按钮控件的父级在控件周围的矩形中无效，它们就会出现。

由于我找不到一个好的示例，因此我提供了完整的代码（在我自己的解决方案中，我已将所有者绘制的控件封装到他们自己的类中，因此您需要提供一些详细信息，例如是否检查按钮或不是）

这是单选按钮的创建（将其添加到父窗口），还设置 GWL_UserData 并子类化单选按钮：

HWND hWndControl = CreateWindow( _T("BUTTON"), caption, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW, 
    xPos, yPos, width, height, parentHwnd, (HMENU) id, NULL, NULL);

// Using SetWindowLong and GWL_USERDATA I pass in the this reference, allowing my 
// window proc toknow about the control state such as if it is selected
SetWindowLong( hWndControl, GWL_USERDATA, (LONG)this);

// And subclass the control - the WndProc is shown later
SetWindowSubclass(hWndControl, OwnerDrawControl::WndProc, 0, 0);

因为它是所有者绘制，所以我们需要在父窗口过程中处理 WM_DRAWITEM 消息。

case WM_DRAWITEM:      
{      
    LPDRAWITEMSTRUCT pDIS = (LPDRAWITEMSTRUCT)lParam;      
    hTheme = OpenThemeData(hDlg, L"BUTTON");          

    HDC dc = pDIS->hDC;      

    wchar_t sCaption[100];      
    GetWindowText(GetDlgItem(hDlg, pDIS->CtlID), sCaption, 100);      
    std::wstring staticText(sCaption);      

    // Controller here passes to a class that holds a map of all controls 
    // which then passes on to the correct instance of my owner draw class
    // which has the drawing code I show below
    controller->DrawControl(pDIS->hwndItem, hTheme, dc, pDIS->rcItem, 
        staticText, pDIS->CtlID, pDIS->itemState, pDIS->itemAction);    

    SetBkMode(dc, TRANSPARENT);      
    SetTextColor(hdcStatic, RGB(0,0,0));     

    CloseThemeData(hTheme);                                 
    return TRUE;      

}    

这是 DrawControl 方法 - 它可以访问类级别变量以允许管理状态，因为对于所有者绘制，这不会自动处理。

void OwnerDrawControl::DrawControl(HWND hwnd, HTHEME hTheme, HDC dc, bool checked, RECT rcItem, std::wstring caption, int ctrlId, UINT item_state, UINT item_action)
{   
    // Check if we need to draw themed data    
    if (hTheme)
    {   
        HWND parent = GetParent(hwnd);      

        static const int cb_size = 13;                      

        RECT bgRect, textRect;
        HFONT font = (HFONT)SendMessageW(hwnd, WM_GETFONT, 0, 0);

        DWORD state;

        // This method handles both radio buttons and checkboxes - the enums here
        // are part of my own code, not Windows enums.
        // We also have hot tracking - this is shown in the window subclass later
        if (Type() == RADIO_BUTTON) 
            state = ((checked) ? RBS_CHECKEDNORMAL : RBS_UNCHECKEDNORMAL) | ((is_hot_) ? RBS_HOT : 0);      
        else if (Type() == CHECK_BOX)
            state = ((checked) ? CBS_CHECKEDNORMAL : CBS_UNCHECKEDNORMAL) | ((is_hot_) ? RBS_HOT : 0);      

        GetClientRect(hwnd, &bgRect);

        // the theme type is either BP_RADIOBUTTON or BP_CHECKBOX where these are Windows enums
        DWORD theme_type = ThemeType(); 

        GetThemeBackgroundContentRect(hTheme, dc, theme_type, state, &bgRect, &textRect);

        DWORD dtFlags = DT_VCENTER | DT_SINGLELINE;

        if (dtFlags & DT_SINGLELINE) /* Center the checkbox / radio button to the text. */
            bgRect.top = bgRect.top + (textRect.bottom - textRect.top - cb_size) / 2;

        /* adjust for the check/radio marker */
        // The +3 and +6 are a slight fudge to allow the focus rectangle to show correctly
        bgRect.bottom = bgRect.top + cb_size;
        bgRect.left += 3;
        bgRect.right = bgRect.left + cb_size;       

        textRect.left = bgRect.right + 6;       

        DrawThemeBackground(hTheme, dc, theme_type, state, &bgRect, NULL);          
        DrawThemeText(hTheme, dc, theme_type, state, caption.c_str(), lstrlenW(caption.c_str()), dtFlags, 0, &textRect);                    

        // Draw Focus Rectangle - I still don't really like this, it draw on the parent
        // mainly to work around the way DrawFocus toggles the focus rect on and off.
        // That coupled with some of my other drawing meant this was the only way I found
        // to get a reliable focus effect.
        BOOL bODAEntire = (item_action & ODA_DRAWENTIRE);
        BOOL bIsFocused  = (item_state & ODS_FOCUS);        
        BOOL bDrawFocusRect = !(item_state & ODS_NOFOCUSRECT);

        if (bIsFocused && bDrawFocusRect)
        {
            if ((!bODAEntire))
            {               
                HDC pdc = GetDC(parent);
                RECT prc = GetMappedRectanglePos(hwnd, parent);
                DrawFocus(pdc, prc);                
            }
        }   

    }
      // This handles drawing when we don't have themes
    else
    {
          TEXTMETRIC tm;
          GetTextMetrics(dc, &tm);      

          RECT rect = { rcItem.left , 
              rcItem.top , 
              rcItem.left + tm.tmHeight - 1, 
              rcItem.top + tm.tmHeight - 1};    

          DWORD state = ((checked) ? DFCS_CHECKED : 0 ); 

          if (Type() == RADIO_BUTTON) 
              DrawFrameControl(dc, &rect, DFC_BUTTON, DFCS_BUTTONRADIO | state);
          else if (Type() == CHECK_BOX)
              DrawFrameControl(dc, &rect, DFC_BUTTON, DFCS_BUTTONCHECK | state);

          RECT textRect = rcItem;
          textRect.left = rcItem.left + 19;

          SetTextColor(dc, ::GetSysColor(COLOR_BTNTEXT));
          SetBkColor(dc, ::GetSysColor(COLOR_BTNFACE));
          DrawText(dc, caption.c_str(), -1, &textRect, DT_WORDBREAK | DT_TOP);
    }           
}

接下来是用于子类化单选按钮控件的窗口过程 - 这
与所有 Windows 消息一起调用，并在传递未处理的消息之前处理几个消息
进入默认过程。

LRESULT OwnerDrawControl::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam,
                               LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    // Get the button parent window
    HWND parent = GetParent(hWnd);  

    // The page controller and the OwnerDrawControl hold some information we need to draw
    // correctly, such as if the control is already set hot.
    st_mini::IPageController * controller = GetWinLong<st_mini::IPageController *> (parent);

    // Get the control
    OwnerDrawControl *ctrl = (OwnerDrawControl*)GetWindowLong(hWnd, GWL_USERDATA);

    switch (uMsg)
    {       
        case WM_LBUTTONDOWN:
        if (controller)
        {
            int ctrlId = GetDlgCtrlID(hWnd);

            // OnCommand is where the logic for things like selecting a radiobutton
            // and deselecting the rest of the group lives.
            // We also call our Invalidate method there, which redraws the radio when
            // it is selected. The Invalidate method will be shown last.
            controller->OnCommand(parent, ctrlId, 0);       

            return (0);
        }
        break;
        case WM_LBUTTONDBLCLK:
            // We just treat doubleclicks as clicks
            PostMessage(hWnd, WM_LBUTTONDOWN, wParam, lParam);
            break;
        case WM_MOUSEMOVE:
        {
            if (controller)                 
            {
                // This is our hot tracking allowing us to paint the control
                // correctly when the mouse is over it - it sets flags that get
                // used by the above DrawControl method
                if(!ctrl->IsHot())
                {
                    ctrl->SetHot(true);
                    // We invalidate to repaint
                    ctrl->InvalidateControl();

                    // Track the mouse event - without this the mouse leave message is not sent
                    TRACKMOUSEEVENT tme;
                    tme.cbSize = sizeof(TRACKMOUSEEVENT);
                    tme.dwFlags = TME_LEAVE;
                    tme.hwndTrack = hWnd;

                    TrackMouseEvent(&tme);
                }
            }    
            return (0);
        }
        break;
    case WM_MOUSELEAVE:
    {
        if (controller)
        {
            // Turn off the hot display on the radio
            if(ctrl->IsHot())
            {
                ctrl->SetHot(false);        
                ctrl->InvalidateControl();
            }
        }

        return (0);
    }
    case WM_SETFOCUS:
    {
        ctrl->InvalidateControl();
    }
    case WM_KILLFOCUS:
    {
        RECT rcItem;
        GetClientRect(hWnd, &rcItem);
        HDC dc = GetDC(parent);
        RECT prc = GetMappedRectanglePos(hWnd, parent);
        DrawFocus(dc, prc);

        return (0);
    }
    case WM_ERASEBKGND:
        return 1;
    }
    // Any messages we don't process must be passed onto the original window function
    return DefSubclassProc(hWnd, uMsg, wParam, lParam); 

}

最后，难题的最后一小部分是您需要在正确的时间使控件无效（重绘它）。我最终发现，使父级无效可以让绘图 100% 正确地工作。这导致了闪烁，直到我意识到我可以通过仅使与无线电检查一样大的矩形无效来逃脱，而不是像我以前那样与包括文本在内的整个控件一样大。

void InvalidateControl()
{
    // GetMappedRectanglePos is my own helper that uses MapWindowPoints 
    // to take a child control and map it to its parent
    RECT rc = GetMappedRectanglePos(ctrl_, parent_);

    // This was my first go, that caused flicker
    // InvalidateRect(parent_, &rc_, FALSE);    

    // Now I invalidate a smaller rectangle
    rc.right = rc.left + 13;
    InvalidateRect(parent_, &rc, FALSE);                
}

大量的代码和工作本来应该很简单 - 在背景图像上绘制主题单选按钮。希望答案能够减轻其他人的痛苦！

* 对此的一个重要警告是，它仅适用于背景上方的所有者控件（例如填充矩形或图像）100% 正确。不过没关系，因为只有在背景上绘制无线电控件时才需要它。

Answer 2

我前段时间也做过这个。我记得关键是像往常一样创建（单选）按钮。父级必须是对话框或窗口，而不是选项卡控件。您可以采用不同的方式，但我为对话框创建了一个内存 dc (m_mdc) 并在其上绘制了背景。然后为您的对话框添加 OnCtlColorStatic 和 OnCtlColorBtn：

virtual HBRUSH OnCtlColorStatic(HDC hDC, HWND hWnd)
{
    RECT rc;
    GetRelativeClientRect(hWnd, m_hWnd, &rc);
    BitBlt(hDC, 0, 0, rc.right - rc.left, rc.bottom - rc.top, m_mdc, rc.left, rc.top, SRCCOPY);
    SetBkColor(hDC, GetSysColor(COLOR_BTNFACE));
    if (IsAppThemed())
        SetBkMode(hDC, TRANSPARENT);
    return (HBRUSH)GetStockObject(NULL_BRUSH);
}

virtual HBRUSH OnCtlColorBtn(HDC hDC, HWND hWnd)
{
    return OnCtlColorStatic(hDC, hWnd);
}

该代码使用了一些类似于 MFC 的内部类和函数，但我认为您应该明白这一点。正如您所看到的，它从内存直流中绘制这些控件的背景，这是关键。

尝试一下，看看是否有效！

编辑：如果您向对话框添加选项卡控件并将控件放在选项卡上（我的应用程序中就是这种情况），您必须捕获它的背景并将其复制到对话框的内存 dc 中。这是一个有点丑陋的黑客，但它有效，即使机器正在运行一些使用渐变选项卡背景的奢侈主题：

    // calculate tab dispay area

    RECT rc;
    GetClientRect(m_tabControl, &rc);
    m_tabControl.AdjustRect(false, &rc);
    RECT rc2;
    GetRelativeClientRect(m_tabControl, m_hWnd, &rc2);
    rc.left += rc2.left;
    rc.right += rc2.left;
    rc.top += rc2.top;
    rc.bottom += rc2.top;

    // copy that area to background

    HRGN hRgn = CreateRectRgnIndirect(&rc);
    GetRelativeClientRect(m_hWnd, m_tabControl, &rc);
    SetWindowOrgEx(m_mdc, rc.left, rc.top, NULL);
    SelectClipRgn(m_mdc, hRgn);
    SendMessage(m_tabControl, WM_PRINTCLIENT, (WPARAM)(HDC)m_mdc, PRF_CLIENT);
    SelectClipRgn(m_mdc, NULL);
    SetWindowOrgEx(m_mdc, 0, 0, NULL);
    DeleteObject(hRgn);

另一个有趣的点，虽然我们现在很忙，但要让它全部不闪烁，创建父级和子级（按钮、静态、选项卡等）具有 WS_CLIPCHILDREN 和 WS_CLIPSIBLINGS 样式。创建顺序很重要：首先创建放置在选项卡上的控件，然后创建选项卡控件。不是相反（尽管感觉更直观）。这是因为选项卡控件应该剪掉被其上的控件遮挡的区域:)

Answer 3

我不能立即尝试这个，但据我记得，你不需要所有者抽奖。您需要执行以下操作：

1. 从 WM_ERASEBKGND 返回 1。
2. 从 WM_CTLCOLORSTATIC 调用 DrawThemeParentBackground 来绘制背景。
3. 从 WM_CTLCOLORSTATIC 返回 GetStockObject(NULL_BRUSH)。

Answer 4

1. 知道尺寸和坐标单选按钮后，我们将复制
   他们的形象已关闭。
2. 然后我们通过以下方式创建画笔
   BS_PATTERN 样式 CreateBrushIndirect
3. 更远的根据
   通常的方案 - 我们返回该画笔的句柄以回复 COLOR -
   消息（WM_CTLCOLORSTATIC）。

Answer 5

我不知道为什么你做得这么困难，这最好通过 CustomDrawing 解决
这是我的 MFC 处理程序，用于在 CTabCtrl 控件上绘制笔记本。我不太确定为什么需要膨胀矩形，因为如果我不这样做，就会绘制黑色边框。

MS 制造的另一个概念性错误是恕我直言，我必须覆盖 PreErase 绘图阶段而不是 PostErase。但如果我稍后这样做，复选框就会消失。

afx_msg void AguiRadioButton::OnCustomDraw(NMHDR* notify, LRESULT* res) {
    NMCUSTOMDRAW* cd  = (NMCUSTOMDRAW*)notify;            
    if (cd->dwDrawStage == CDDS_PREERASE) {
        HTHEME theme = OpenThemeData(m_hWnd, L"Button");
        CRect r = cd->rc; r.InflateRect(1,1,1,1);
        DrawThemeBackground(theme, cd->hdc, TABP_BODY, 0, &r,NULL);
        CloseThemeData(theme);
        *res = 0;
    }
    *res = 0;    
}