How to move window by right mouse button using C++?

Question

I need to move window by right mouse button. The window has no caption, titlebar. By left button it works

 void CMyHud::OnLButtonDown(UINT nFlags, CPoint point)
{
    // TODO: Add your message handler code here and/or call default
    SendMessage(WM_SYSCOMMAND, SC_MOVE|0x0002);
    CDialogEx::OnLButtonDown(nFlags, point);
}

But if I place this code on OnRButtonDown it dosen't work. What is the problem?

Well, the solution is found, thanks to Mark Ransom:

 CRect pos;

   void CMyHud::OnRButtonDown(UINT nFlags, CPoint point)
    {
        pos.left = point.x;
        pos.top = point.y;
        ::SetCapture(m_hWnd);

        CDialogEx::OnRButtonDown(nFlags, point);
    }


    void CMyHud::OnMouseMove(UINT nFlags, CPoint point)
    {
        CWnd* pWnd = CWnd::FromHandle(m_hWnd);
        CRect r;
        if(GetCapture() == pWnd)
        {
            POINT pt;
            GetCursorPos(&pt);
            GetWindowRect(r);
            pt.x -= pos.left;
            pt.y -= pos.top;
            MoveWindow(pt.x, pt.y, r.Width(), r.Height(),TRUE);
        }

        CDialogEx::OnMouseMove(nFlags, point);
    }


    void CMyHud::OnRButtonUp(UINT nFlags, CPoint point)
    {
        ReleaseCapture();

        CDialogEx::OnRButtonUp(nFlags, point);
    }

You are right OnRbuttonDown is get called but no movement happen for the dialog, I'm trying to find out why it works only with OnLButtonDown. — ahmedsafan86, May 28 '15 at 13:24

score 3 · Accepted Answer · answered May 28 '15 at 19:02

In your OnRButtonDown function, do a SetCapture to ensure all mouse messages are routed to your window while the mouse button is down. Also store the mouse position in a member variable. Now, in your OnMouseMove function, check to see if GetCapture returns an object with the same HWND as yours - if it does, calculate the difference between the current mouse position and the saved one, then call MoveWindow to move the window.

Barmak Shemirani · Answer 2 · 2015-05-28T18:48:50.407

In regards to left-mouse click:

SC_MOVE|0x0002 comes out as 0xF012 or SC_DRAGMOVE. This is apparently an undocumented constant. There is probably a good reason Microsoft doesn't want anybody to use this, that's why they have hidden it.

Also WM_SYSCOMMAND is a notification message. You should respond to it, not send it. To drag the window with left-mouse click:

message map ...
ON_WM_NCHITTEST()

LRESULT CMyDialog::OnNcHitTest(CPoint p)
{
    //responding to a notification message
    return HTCAPTION; 
}

To drag the window with right-mouse you have to override OnRButtonDown, OnMouseMove, OnRButtonUp and make your own routine. But Window's behaviour gets very confusing. Is that really worth it?

With left mouse button it works perfectly. I need right button. The solution is found by your and marks advice. Thanks! — Nika_Rika, May 29 '15 at 05:39

score 0 · Answer 3 · answered May 29 '15 at 08:44

0

you can use mouse message to realize. WM_RBUTTONDOWN, WM_MOUSEMOVE

answered May 29 '15 at 08:44

allen

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How to move window by right mouse button using C++?

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