CTreeCtrl的使用和一个CTreeCtrl的派生类

 1.树视图风格:
TVS_HASBUTTONS;    //在父项旁边显示(+)和(-)
      TVS_HASLINES;     //使用线条显示各项之间的层次
      TVS_LINESATROOT;//使用线条链接树视图控件根部各项

2.处理单击事件:TVN_SELCHANGED
void CTreeCtrlDlg::OnTvnSelchangedTree1(NMHDR *pNMHDR, LRESULT *pResult)
{
      LPNMTREEVIEW pNMTreeView = reinterpret_cast<LPNMTREEVIEW>(pNMHDR);
      // TODO: 在此添加控件通知处理程序代码
      HTREEITEM ht=m_treeCtrl.GetSelectedItem();
      CString strSelect=m_treeCtrl.GetItemText(ht);
      m_strTreeVal=strSelect;
      UpdateData(FALSE);
      *pResult = 0;
}

3.同时让自己派生的CMyTreeCtrl类和对话框处理TVN_SELCHANGED消息:
只须在CMyTreeCtrl中处理以下消息,并返回FALSE就OK了ON_NOTIFY_REFLECT_EX(TVN_SELCHANGED, OnTvnSelchanged) OnTvnSelchanged的签名如下
BOOL CMyTreeCtrl::OnTvnSelchanged(NMHDR *pNMHDR,LRESULT *pResult)

4.编辑标签:要允许编辑树视图控件中的文本,可以设置以下三个步骤
      1.设置树视图的TVS_EDITLABELS风格
TVS_EDITLABE可以通过资源编辑框内部修改(Edit labels),也可以用代码的方式修改,如下
long lStyle=::GetWindowLong(m_treeCtrl.GetSafeHwnd(),GWL_STYLE);
      lStyle|=TVS_EDITLABELS;
      ::SetWindowLong(m_treeCtrl.GetSafeHwnd(),GWL_STYLE,lStyle)
      2.处理TVN_BEGINLABELEDIT通知消息
       //设置相关限制,如限制编辑框字符串长度
CEdit*pEdit=GetEditControl();     //获取当前选中结点编辑框
      ASSERT(pEdit);
      if (pEdit)
     {
          pEdit->LimitText(15);//设置编辑框文本长度为15个字符串
          *pResult = 0;       
      }
      3.处理TVN_ENDLABLEEDIT通知消息
      HTREEITEM hParent=GetParentItem(pTVDispInfo->item.hItem); //获取父结点  
      HTREEITEM hChild=GetChildItem(hParent?hParent:TVI_ROOT); //获取第一个根结点
hChild=GetNextSiblingItem(hChild);            //获取下一个兄弟节点
if (pTVDispInfo->item.hItem!=hChild)          //判断是否与当前节点相同
pTVDispInfo->item.pszText                     //获取当前节点的字符串
CString strText=GetItemText(hChild);          //获取节点的字符串

3.让树视图处理Esc和Enter键
重载PreTranslateMessage函数
BOOL bHandleMsg=FALSE;
      switch(pMsg->message){
      case VK_ESCAPE:
      case VK_RETURN:
          if (::GetKeyState(VK_CONTROL)&0x8000)
        {
              break;
          }
          if (GetEditControl())
          {
              ::TranslateMessage(pMsg);
              ::DispatchMessage(pMsg);
              bHandleMsg=TRUE;
          }
          break;
      }

4.实现上下文菜单
在WM_RBUTTONDOWN消息处理函数上实现上下文菜单

5.展开和收起树视图结点:
HTREEITEM hItem=GetRootItem();                //获取根结点,可能会有多个根结点
ItemHasChildren(hParent)                      //判断结点是否有孩子结点
hItem=GetChildItem(hParent);                  //获取第一个子结点
hItem=GetNextSiblingItem(hItem));             //获取下一个兄弟结点结点
Expand(hItem,bExpand?TVE_EXPAND:TVE_COLLAPSE);//展开/叠起结点
Select(hItem,TVGN_FIRSTVISIBLE);                  //设置选中结点
CString str=GetItemText(hChild);              //获取结点字符串信息
HTREEITEM hCurrSel = GetSelectedItem();       //获取当前选中结点
SelectItem(hNewSel);
HTREEITEM hNewSel = HitTest(pt, &nFlags);         //判断坐标是否在当前结点范围内
HTREEITEM hItem=InsertItem(dlg.m_strItemText,hItemParent);    //插入结点
#pragma once
//定义文件MyTreeCtrl.h
// CMyTreeCtrl
class CMyTreeCtrl : public CTreeCtrl
{
      DECLARE_DYNAMIC(CMyTreeCtrl)
public:
      CMyTreeCtrl();
      virtual ~CMyTreeCtrl();
protected:
      DECLARE_MESSAGE_MAP()
      void ExpandBranch(HTREEITEM hItem,BOOL bExpand =TRUE);
public:
      void ExpandAllBranches(BOOL bExpand =TRUE);
      BOOL DoesItemExist(HTREEITEM hItemParent, CString const& strItem);
      afx_msg void OnRButtonDown(UINT nFlags, CPoint point);
      afx_msg void OnAddItem();
      virtual BOOL PreTranslateMessage(MSG* pMsg);
      afx_msg void OnTvnBeginlabeledit(NMHDR *pNMHDR, LRESULT *pResult);
      afx_msg void OnTvnEndlabeledit(NMHDR *pNMHDR, LRESULT *pResult);
    
      afx_msg BOOL OnTvnSelchanged(NMHDR *pNMHDR, LRESULT *pResult);
};
// MyTreeCtrl.cpp : 实现文件
#include "stdafx.h"
#include "TreeCtrl.h"
#include "MyTreeCtrl.h"
#include ".mytreectrl.h"
#include "AddItemDlg.h" 
// CMyTreeCtrl
IMPLEMENT_DYNAMIC(CMyTreeCtrl, CTreeCtrl)
CMyTreeCtrl::CMyTreeCtrl()
{
}
CMyTreeCtrl::~CMyTreeCtrl()
{
}
BEGIN_MESSAGE_MAP(CMyTreeCtrl, CTreeCtrl)
      ON_WM_RBUTTONDOWN()
      ON_COMMAND(IDR_ADD_ITEM, OnAddItem)
      ON_NOTIFY_REFLECT(TVN_ENDLABELEDIT, OnTvnEndlabeledit)
      ON_NOTIFY_REFLECT(TVN_BEGINLABELEDIT, OnTvnBeginlabeledit)
      ON_NOTIFY_REFLECT_EX(TVN_SELCHANGED, OnTvnSelchanged)
END_MESSAGE_MAP()

// CMyTreeCtrl 消息处理程序
void CMyTreeCtrl::ExpandBranch(HTREEITEM hItem,BOOL bExpand /* =TRUE */)
//展开
{
      if (ItemHasChildren(hItem))    //判断是否有孩子结点
      {
          Expand(hItem,bExpand?TVE_EXPAND:TVE_COLLAPSE);
          //展开/叠起结点
          hItem=GetChildItem(hItem);//获取第一个子结点
          do {
              ExpandBranch(hItem);
          } while(hItem=GetNextSiblingItem(hItem));//获取兄弟结点
      }
}
void CMyTreeCtrl::ExpandAllBranches(BOOL bExpand /* =TRUE */)
{
      HTREEITEM hItem=GetRootItem();//获取根结点,可能会有多个根结点
      do {
          ExpandBranch(hItem,bExpand);
      } while(hItem=GetNextSiblingItem(hItem));
      Select(hItem,TVGN_FIRSTVISIBLE);//设置选中结点
}
BOOL CMyTreeCtrl::DoesItemExist(HTREEITEM hItemParent,
                                  CString const& strItem)
{
      BOOL bDoesItemExist=FALSE;
      ASSERT(strItem.GetLength());
      HTREEITEM hChild=GetChildItem(hItemParent?hItemParent:TVI_ROOT);
      while (NULL!=hChild&&!bDoesItemExist)
      {
          CString str=GetItemText(hChild);//获取结点字符串信息
          if (0==str.CompareNoCase(strItem))
          {
              bDoesItemExist=TRUE;
          }
          else
          {
              hChild=GetNextSiblingItem(hChild);
          }
      }
      return bDoesItemExist;
}
void CMyTreeCtrl::OnRButtonDown(UINT nFlags, CPoint point)
{
      // TODO: 在此添加消息处理程序代码和/或调用默认值    
      // set focus to the tree control
      SetFocus();

      // map the point that is passed to the 
      // function from client coordinates
      // to screen coordinates
      ClientToScreen(&point);
      // Get the currently selected item
      HTREEITEM hCurrSel = GetSelectedItem();//获取当前选中结点
      // Figure out which item was right clicked
      CPoint pt(0, 0);
      ::GetCursorPos(&pt);
      ScreenToClient (&pt);
      HTREEITEM hNewSel = HitTest(pt, &nFlags);
      // Set the selection to the item that the
      // mouse was over when the user right
      // clicked
      if (NULL == hNewSel)
      {
          SelectItem(NULL);
      }
      else if (hCurrSel != hNewSel)
      {
          SelectItem(hNewSel);
          SetFocus();
      }

      // Load the context menu
      CMenu Menu;
      if (Menu.LoadMenu(IDM_CONTEXT_MENU))
      {
          CMenu* pSubMenu = Menu.GetSubMenu(0);
          if (pSubMenu!=NULL)
          {
              // Display the context menu
              pSubMenu->TrackPopupMenu(
                  TPM_LEFTALIGN | TPM_RIGHTBUTTON,
                  point.x, point.y, this);
          }
      }   
}
void CMyTreeCtrl::OnAddItem()
//添加上下文菜单
{
      // TODO: 在此添加命令处理程序代码
      HTREEITEM hItemParent=GetSelectedItem();
      //获取当前选中结点
      CAddItemDlg dlg;
      if (dlg.DoModal()==IDOK)
      {
          if (!DoesItemExist(hItemParent,dlg.m_strItemText))
          {
              HTREEITEM hItem=InsertItem(dlg.m_strItemText,hItemParent);
              //插入结点
              SelectItem(hItem);
          }
          else
          {
              AfxMessageBox("已存在相同结点");
          }
      }
   
}
BOOL CMyTreeCtrl::PreTranslateMessage(MSG* pMsg)
{
      // TODO: 在此添加专用代码和/或调用基类
      BOOL bHandledMsg = FALSE; 

      switch (pMsg->message) 
      { 
          case WM_KEYDOWN: 
          { 
              switch (pMsg->wParam) 
              { 
              case VK_ESCAPE:
              case VK_RETURN:    
                  if (::GetKeyState(VK_CONTROL) & 0x8000) 
                  { 
                      break; 
                  } 
                  if (GetEditControl())
                  {
                      ::TranslateMessage(pMsg);
                      ::DispatchMessage(pMsg);
                      bHandledMsg = TRUE; 
                  }
                  break; 
              default: break; 
              } // switch (pMsg->wParam) 
          } // WM_KEYDOWN 
          break; 
      default: break; 
      } // switch (pMsg->message)                   
      // continue normal translation and dispatching              
      return (bHandledMsg ?TRUE : CTreeCtrl::PreTranslateMessage(pMsg));

}
void CMyTreeCtrl::OnTvnBeginlabeledit(NMHDR *pNMHDR, LRESULT *pResult)
{
      LPNMTVDISPINFO pTVDispInfo = reinterpret_cast<LPNMTVDISPINFO>(pNMHDR);
      // TODO: 在此添加控件通知处理程序代码
      *pResult=1;
      CEdit*pEdit=GetEditControl();
      ASSERT(pEdit);
      if (pEdit)
      {
          pEdit->LimitText(15);
          *pResult=0;
      }   
}
void CMyTreeCtrl::OnTvnEndlabeledit(NMHDR *pNMHDR, LRESULT *pResult)
{
      LPNMTVDISPINFO pTVDispInfo = reinterpret_cast<LPNMTVDISPINFO>(pNMHDR);
      // TODO: 在此添加控件通知处理程序代码

      BOOL bValidItem=FALSE;
      CString strItem=pTVDispInfo->item.pszText;
      if (0<strItem.GetLength())
      {
          HTREEITEM hParent=GetParentItem(pTVDispInfo->item.hItem);
          bValidItem=!DoesItemExist(hParent,strItem);     
      }
      *pResult = bValidItem;
} 
BOOL CMyTreeCtrl::OnTvnSelchanged(NMHDR *pNMHDR, LRESULT *pResult)
{
      LPNMTREEVIEW pNMTreeView = reinterpret_cast<LPNMTREEVIEW>(pNMHDR);
      // TODO: 在此添加控件通知处理程序代码
      TRACE(GetItemText(pNMTreeView->itemNew.hItem));
      TRACE(" ");
      *pResult = 0;
      return FALSE;         //返回FALSE可以让父窗口进行进一步的处理
}