可以使用Drag&Drop的CTreeView
闻怡洋译
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CTreeViewExt是MFC使用者可重用的类，该类由CTreeView派生，可以用在文档-视结构的应用程序中，并且支持Drag&Drop。
使用者所需要做的仅仅是将文件加到AppWizard产生的工程中，(CTreeView为基类)并且将CTreeView替换为CTreeViewExt。并重载三个Virtual Function。
WenYY:这很简单吧，下面是源代码，我会在必要的地方加上注释，但由于原作者并未加，所以如果有出入请原谅，作者定义了三处虚拟函数，其作用是让使用者重载后，加入自己的判断条件和结果处理的功能，很巧妙的思想：
CopyItemProperties
IsItemCanBeDroppedOn(HTREEITEM hSource, HTREEITEM hTarget);
BOOL ItemCanBeDragged(HTREEITEM hItem);//检查是否可以对该ITEM实施Drag&Drop
Header file
#if !defined(AFX_TREEVIEWEXT_H__99D8F6F8_79F0_11D1_8DC6_0000E8125FE5__INCLUDED_)
#define AFX_TREEVIEWEXT_H__99D8F6F8_79F0_11D1_8DC6_0000E8125FE5__INCLUDED_
#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
// TreeViewExt.h : header file
//
/////////////////////////////////////////////////////////////////////////////
// CTreeViewExt view
class CTreeViewExt : public CTreeView
{
protected:
CTreeViewExt(); // protected constructor used by dynamic creation
DECLARE_DYNCREATE(CTreeViewExt)
// Attributes
public:
// Operations
public:
// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CTreeViewExt)
protected:
virtual void OnDraw(CDC* pDC); // overridden to draw this view
//}}AFX_VIRTUAL
// Implementation
protected:
HTREEITEM m_hDraggedItem;
BOOL m_bDraggingNow; //标记
CImageList *m_pDragImageList;
virtual ~CTreeViewExt();
#ifdef _DEBUG
virtual void AssertValid() const;
virtual void Dump(CDumpContext& dc) const;
#endif
// Generated message map functions
protected:
virtual void CopyItemProperties(HTREEITEM hNewItem, HTREEITEM hDraggedItem);
virtual BOOL IsItemCanBeDroppedOn(HTREEITEM hSource, HTREEITEM hTarget);
virtual BOOL ItemCanBeDragged(HTREEITEM hItem);//检查是否可以对该ITEM实施Drag&Drop
//{{AFX_MSG(CTreeViewExt)
afx_msg void OnBegindrag(NMHDR* pNMHDR, LRESULT* pResult);//必须重载的函数
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
/////////////////////////////////////////////////////////////////////////////
//{{AFX_INSERT_LOCATION}}
// Microsoft Developer Studio will insert additional declarations immediately before the previous line.
#endif // !defined(AFX_TREEVIEWEXT_H__99D8F6F8_79F0_11D1_8DC6_0000E8125FE5__INCLUDED_)
Implementation file
// TreeViewExt.cpp : implementation file
//
#include "stdafx.h"
#include "TreeViewExt.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CTreeViewExt
IMPLEMENT_DYNCREATE(CTreeViewExt, CTreeView)
CTreeViewExt::CTreeViewExt()
{
m_bDraggingNow = FALSE;
m_hDraggedItem = NULL;
m_pDragImageList = NULL;
}
CTreeViewExt::~CTreeViewExt()
{
}
BEGIN_MESSAGE_MAP(CTreeViewExt, CTreeView)
//{{AFX_MSG_MAP(CTreeViewExt)
ON_NOTIFY_REFLECT(TVN_BEGINDRAG, OnBegindrag)
ON_WM_MOUSEMOVE()
ON_WM_LBUTTONUP()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CTreeViewExt drawing
void CTreeViewExt::OnDraw(CDC* pDC)
{
CDocument* pDoc = GetDocument();
// TODO: add draw code here
}
/////////////////////////////////////////////////////////////////////////////
// CTreeViewExt diagnostics
#ifdef _DEBUG
void CTreeViewExt::AssertValid() const
{
CTreeView::AssertValid();
}
void CTreeViewExt::Dump(CDumpContext& dc) const
{
CTreeView::Dump(dc);
}
#endif //_DEBUG
/////////////////////////////////////////////////////////////////////////////
// CTreeViewExt message handlers
void CTreeViewExt::OnBegindrag(NMHDR* pNMHDR, LRESULT* pResult)
{
NM_TREEVIEW* pNMTreeView = (NM_TREEVIEW*)pNMHDR;
if (!m_bDraggingNow)
{//先检查是否正在过程中
if (ItemCanBeDragged(pNMTreeView->itemNew.hItem))
{//查询条件，是否允许Drag&Drop
CTreeCtrl& tree = GetTreeCtrl();
tree.SetCapture();
m_bDraggingNow = TRUE;
m_hDraggedItem = pNMTreeView->itemNew.hItem;//保存变量
tree.Select(m_hDraggedItem, TVGN_CARET);
m_pDragImageList = tree.CreateDragImage(m_hDraggedItem);
m_pDragImageList->DragEnter(&tree, pNMTreeView->ptDrag);
m_pDragImageList->BeginDrag(0, CPoint(0, 0));
}
}
*pResult = 0;
}
void CTreeViewExt::OnMouseMove(UINT nFlags, CPoint point)
{
if (m_bDraggingNow)
{
CTreeCtrl& tree = GetTreeCtrl();
m_pDragImageList->DragEnter(&tree, point);
m_pDragImageList->DragMove(point);
}
CTreeView::OnMouseMove(nFlags, point);
}
void CTreeViewExt::OnLButtonUp(UINT nFlags, CPoint point)
{
if (m_bDraggingNow)
{
ReleaseCapture();
m_bDraggingNow = FALSE;
m_pDragImageList->EndDrag();
delete m_pDragImageList;
m_pDragImageList = NULL;
CTreeCtrl& tree = GetTreeCtrl();
UINT flags;
HTREEITEM hTargetItem = tree.HitTest(point, &flags);//得到目标
if (hTargetItem != NULL && IsItemCanBeDroppedOn(m_hDraggedItem, hTargetItem))
{//查询是否可以成功完成,条件是开始时选中的Item和结束使选中的ITEM是否满足你的条件
HTREEITEM hNewItem = tree.InsertItem("Untitled", hTargetItem);
CopyItemProperties(hNewItem, m_hDraggedItem);//进行处理
if (nFlags != MK_CONTROL)
tree.DeleteItem(m_hDraggedItem);
}
m_hDraggedItem = NULL;
}
CTreeView::OnLButtonUp(nFlags, point);
}
BOOL CTreeViewExt::ItemCanBeDragged(HTREEITEM hItem)
{//作用为决定现在是否能开始,可以作为一种运行时的选项
return FALSE;
}
BOOL CTreeViewExt::IsItemCanBeDroppedOn(HTREEITEM hSource, HTREEITEM hTarget)
{//决定现在结束条件是否正常，如不正常则放弃这次操作
return FALSE;
}
void CTreeViewExt::CopyItemProperties(HTREEITEM hNewItem, HTREEITEM hDraggedItem)
{//按照你的需要对两个ITEM进行处理。
}
