使用动态菜单的命令范围

Question

这可能是一个非常基本的问题，但是由于新手不明白原因，基本上我想要树控件上的弹出菜单，例如，右键单击树控件会弹出一个菜单，并且在此菜单的基础上，其他功能继续进行。为此，我使用了以下代码，

在.h文件中，

#define NEW_RELAY_MENU_START                    WM_USER + 1
#define NEW_RELAY_MENU_END                  WM_USER + 256

在 .cpp 文件中

BEGIN_MESSAGE_MAP(CCtrlModDefDlgTree, CTreeCtrl)
    ON_NOTIFY_REFLECT(TVN_SELCHANGED, OnSelChangedTreeCtrl)
    ON_NOTIFY_REFLECT(NM_RCLICK, &CCtrlModDefDlgTree::OnNMRClick)
    ON_COMMAND_RANGE(NEW_RELAY_MENU_START,NEW_RELAY_MENU_END,CCtrlModDefDlgTree::OnNewMenu)
END_MESSAGE_MAP()

CCtrlModDefDlgTree::CCtrlModDefDlgTree()
{
    NumberOfRelays.RemoveAll();
    NumberOfRelays.Add(L"MENU1");
    NumberOfRelays.Add(L"MENU2");
    NumberOfRelays.Add(L"MENU3");
    NumberOfRelays.Add(L"MENU4");
    NumberOfRelays.Add(L"MENU5);
    NumberOfRelays.Add(L"MENU6");   
}
void CCtrlModDefDlgTree::OnNMRClick(NMHDR *pNMHDR, LRESULT *pResult)
{
    // TODO: Add your control notification handler code here
     /* Get the cursor position for this message */ 
    DWORD dwPos = GetMessagePos(); 
    /* Convert the co-ords into a CPoint structure */ 
    CPoint pt( GET_X_LPARAM( dwPos ), GET_Y_LPARAM ( dwPos ) ); 
    CPoint spt; 
    spt = pt; 
    /* convert to screen co-ords for the hittesting to work */ 
    ScreenToClient( &spt ); 
    UINT test; 
    HTREEITEM hti = HitTest( spt, &test ); 
    if ( hti != NULL  ) 
    { 
            /* Is the click atcually *on* the item? */ 
            if ( test & TVHT_ONITEM ) 
            { 
                    /* Do the normal context menu stuff */ 
                    ShowPopupMenu(  pt ); 
            } 
    } 
    *pResult = 0; 
}
void CCtrlModDefDlgTree::ShowPopupMenu( CPoint& point )
{
        if (point.x == -1 && point.y == -1)
        {
            //keystroke invocation
            CRect rect;
            GetClientRect(rect);
            ClientToScreen(rect);
            point = rect.TopLeft();
            point.Offset(5, 5);
        }

        //create a menu object for main menu
        CMenu *menu    = new CMenu();
        menu->CreatePopupMenu();

        //another menu object for submenu
        CMenu *subMenu = new CMenu();
        subMenu->CreatePopupMenu();
        for(int __index = 0;__index<NumberOfRelays.GetCount();__index++)
        {
            subMenu->AppendMenu(MF_STRING, NEW_RELAY_MENU_START+__index, NumberOfRelays.ElementAt(__index));
        }
        //append submenu to menu
        menu->AppendMenu(MF_POPUP|MF_STRING, (UINT)subMenu->m_hMenu,  _T("New Menu") );
        ASSERT(menu != NULL);
        CWnd* pWndPopupOwner = this;
        while (pWndPopupOwner->GetStyle() & WS_CHILD)
            pWndPopupOwner = pWndPopupOwner->GetParent();
        menu->TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON, point.x, point.y,
            pWndPopupOwner);
}

void CCtrlModDefDlgTree::OnNewMenu(UINT nID)
{
}

但是我的 OnNewMenu() 函数在菜单点击时没有被调用。甚至所有的菜单都默认启用。我做错了什么？

Answer 1

您已将命令范围添加到树控件的消息映射中，但您没有将树控件用作菜单的所有者窗口。

CWnd* pWndPopupOwner = this;
while (pWndPopupOwner->GetStyle() & WS_CHILD)
    pWndPopupOwner = pWndPopupOwner->GetParent();

这将找到顶层窗口并将其用作弹出窗口的所有者，这意味着来自弹出窗口的WM_COMMAND 消息将转到顶层窗口而不是树。您需要将命令范围添加到该窗口的消息映射中。

或者，您可以将TPM_RETURNCMD 标志与TrackPopupMenu 一起使用，这将返回选定的命令ID，然后您自己调用OnNewMenu() 函数：

int iID = menu->TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON | TPM_RETURNCMD, 
            point.x, point.y, pWndPopupOwner);
if (iID) OnNewMenu(iID);