About CTreeView and CTreeCtrl

From:

gmclee@21cn.com

Newsgroups:

microsoft.public.vc.mfc

Date:

25 Mar 2007 09:40:17 -0700

Message-ID:

<1174840817.028732.138400@y80g2000hsf.googlegroups.com>

Hi there,
  I would like to apply a derived CTreeCtrl in CMyTreeView which is
derived from CTreeView. For that purpose, I refer to the following
articles

http://www.codeguru.com/doc_view/custom_view.shtml
http://www.codeguru.com/doc_view/Control2View.shtml

My code of my code are:

class CMyTreeView : public CTreeView
{
protected:
  CMyTreeView ();
  DECLARE_DYNCREATE(CMyTreeView )
public:
  CMyDoc* GetDocument();
  CMyTreeCtrl& GetTreeCtrl() const;

  virtual void OnDraw(CDC* pDC); // overridden to draw this view
  virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
  virtual ~CMyTreeView ();

protected:
  virtual void OnInitialUpdate(); // called first time after construct
  CMyTreeCtrl m_TreeCtrl;
  afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
  afx_msg void OnSize(UINT nType, int cx, int cy);
};

// OnCreate and OnSize are implemented as follow
IMPLEMENT_DYNCREATE(CDragView, CTreeView)

BEGIN_MESSAGE_MAP(CMyTreeView, CTreeView)
  //{{AFX_MSG_MAP(CMyTreeView)
  ON_WM_CREATE()
  ON_WM_SIZE()
END_MESSAGE_MAP()

CMyTreeCtrl& CMyTreeView::GetTreeCtrl() const
{
  return (CMyTreeCtrl &)CTreeView::GetTreeCtrl();
}

int CMyTreeView::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
  if (CTreeView::OnCreate(lpCreateStruct) == -1) return -1;

  DWORD dwStyle = WS_CHILD | WS_VISIBLE | WS_TABSTOP;
  BOOL bResult = m_TreeCtrl.Create(dwStyle, CRect(0,0,0,0), this,
IDC_TREEVIEW);
  return (bResult ? 0 : -1);
}

void CMyTreeView::OnSize(UINT nType, int cx, int cy)
{
  CTreeView::OnSize(nType, cx, cy);
  if (::IsWindow(m_TreeCtrl.m_hWnd)) m_TreeCtrl.MoveWindow(0, 0, cx,
cy, TRUE);
}

Here, CMyTreeCtrl is a class derived from CTreeCtrl, as follow

class CMyTreeCtrl : public CTreeCtrl
{
public:
  CMyTreeCtrl ();
  virtual ~CMyTreeCtrl ();

protected:
  afx_msg void OnBeginlabeledit(NMHDR* pNMHDR, LRESULT* pResult);
  afx_msg void OnBegindrag(NMHDR* pNMHDR, LRESULT* pResult);
  afx_msg void OnEndlabeledit(NMHDR* pNMHDR, LRESULT* pResult);
  afx_msg void OnMouseMove(UINT nFlags, CPoint point);
  afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
  afx_msg void OnContextMenu(CWnd* pWnd, CPoint point);
  afx_msg void OnRclick(NMHDR* pNMHDR, LRESULT* pResult);
  afx_msg void OnBeginrdrag(NMHDR* pNMHDR, LRESULT* pResult);
  afx_msg void OnRButtonUp(UINT nFlags, CPoint point);
  afx_msg void OnRButtonDown(UINT nFlags, CPoint point);
  afx_msg void OnSelchanging(NMHDR* pNMHDR, LRESULT* pResult);
  //}}AFX_MSG
  afx_msg void OnContextCmd(UINT uID);
  afx_msg void OnDragContextCmd(UINT uID);
  DECLARE_MESSAGE_MAP()
};

Note that this class is developed to handle the drag and drop issue
(the original code is from codeproject.com, Full-Featured Tree
Control, By J=F6rg K=F6nig. )

So far, everything is all right. I am sure the CMyTreeView recognize
the derived CMyTreeCtrl. I have also written a simple code to test if
CMyTreeView can show the tree view properly. It does, of course!
However, I found that ALMOST all messaged defined in CMyTreeCtrl will
not be catched within CMyTreeCtrl, so that the function of drag&drop
doesn't work. I am wondering how to notify CMyTreeCtrl the messages?

By the way, strangely enough, I found CMyTreeCtrl does catch the
messages of OnCntextCmd and OnDragContext, what's going on?

Thanks in advance.