MFC：如何为 OnInitMenuPopup 上添加的 CMenu 项目添加位图？

Question

我需要根据需要添加自定义菜单项。我发现OnInitMenuPopup (WM_INITMENUPOPUP) 可以满足我的需要，但我无法在菜单上的文本旁边显示一个图标？我尝试使用m_MyGraphic 作为CPngImage 的16x16 png 图形，我尝试将其附加到CBitmap，我尝试将图形保存为.bmp 并加载为CBitmap。我试过不在负载上设置图形，然后尝试使用SetMenuItemBitmaps()，我尝试了 13x13 图形，我尝试了 15x15 图形（与 GetMenuCheckMarkDimensions() 匹配）。菜单项旁边永远不会显示图形？我做错了什么或错过了什么？

TIA！

void CMainFrame::OnInitMenuPopup(CMenu* pPopupMenu, UINT nIndex, BOOL bSysMenu)
{
  // add items
  if (pPopupMenu && pPopupMenu->GetMenuItemCount() > 0 && pPopupMenu->GetMenuItemID(0) == ID_MY_EXPECTED_ID) {
    // loop though and add menu items
    for (UINT i=0; i<theApp.m_MyList.GetCount(); i++) {
      CString s;
      s.Format(_T("%i: %s"), i, theApp.m_MyList[i].String);
      MENUITEMINFO mii={};
      mii.cbSize=sizeof(mii);
      mii.fMask=MIIM_ID|MIIM_STRING|MIIM_BITMAP;
      mii.wID=ID_MY_RANGE_0+i;
      mii.dwTypeData=s.GetBuffer();
      mii.hbmpItem=(HBITMAP)m_MyBitmap.GetSafeHandle();
      pPopupMenu->InsertMenuItem(i+1, &mii, TRUE);
      // not working above so tried using this as well but it doesn't work either:
      //pPopupMenu->SetMenuItemBitmaps(i+1, MF_BYPOSITION, &m_MyBitmap, &m_MyBitmap);
    }
  }

  CFrameWndEx::OnInitMenuPopup(pPopupMenu, nIndex, bSysMenu);
}

Answer 1

我找到了解决办法。首先在初始化的某处添加CMFCToolBarMenuButton::m_bAlwaysCallOwnerDraw=TRUE;。

然后处理绘制它：

BOOL CMainFrame::OnDrawMenuImage(CDC* pDC, const CMFCToolBarMenuButton* pMenuButton, const CRect& rectImage)
{
  BOOL result=FALSE;
  if (pMenuButton->m_nID>=ID_MY_RANGE_0 && pMenuButton->m_nID<=ID_MY_RANGE_N) {

    // size to use on menu
    CSize sizemenuimage = CMFCToolBar::GetMenuImageSize();

    // get size of our bitmap
    BITMAP bitmap;
    m_MyBitmap.GetBitmap(&bitmap);

    // create dc to attach bitmap to
      CDC dcmem;
    if (dcmem.CreateCompatibleDC(pDC)) {
      // attach bitmap to dc
      CBitmap * poldbitmap=dcmem.SelectObject(&m_MyBitmap);
      if (poldbitmap) {
        // Draw bitmap
        result=pDC->StretchBlt(rectImage.left+(rectImage.Width()-sizemenuimage.cx)/2, 
                               rectImage.top+(rectImage.Height()-sizemenuimage.cy)/2, 
                               sizemenuimage.cx, sizemenuimage.cy, 
                               &dcmem, 0, 0, bitmap.bmWidth, bitmap.bmHeight, SRCCOPY);
        // Select original object
        dcmem.SelectObject(poldbitmap);
      }
      dcmem.DeleteDC();
    }
  }

  return result;
}

Answer 2

另一种可能的解决方案（如果您已经有工具栏的位图）是：

void CMainFrame::OnInitMenuPopup(CMenu* pPopupMenu, UINT nIndex, BOOL bSysMenu) 
{
    CMDIFrameWnd::OnInitMenuPopup(pPopupMenu, nIndex, bSysMenu);

    // TODO: Add your message handler code here

    HICON hIcon = AfxGetApp()->LoadIcon(IDR_TESTMETYPE);
    pPopupMenu->SetMenuItemBitmaps(ID_FILE_NEW, MF_BYCOMMAND, ConvertIconToBitmap(hIcon), NULL);
    ...
    ...
}

其中 SetMenuItemBitmaps 定义为：

CBitmap* CMainFrame::ConvertIconToBitmap(HICON hIcon)
{
    CDC dc;
    CBitmap bmp;
    CClientDC ClientDC(this);
    dc.CreateCompatibleDC(&ClientDC);
    bmp.CreateCompatibleBitmap(&ClientDC, 13, 13);
    CBitmap* pOldBmp = (CBitmap*)dc.SelectObject(&bmp);
    ::DrawIconEx(dc.GetSafeHdc(), 0, 0, hIcon, 13, 13, 0, (HBRUSH)RGB(255, 255, 255), DI_NORMAL);
    dc.SelectObject(pOldBmp);
    dc.DeleteDC();
    HBITMAP hBitmap = (HBITMAP)::CopyImage((HANDLE)((HBITMAP)bmp), 
            IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE);

    return CBitmap::FromHandle(hBitmap);
}