创建一个带有CheckBox的TreeView

　　void __fastcall TForm1::FormCreate(TObject *Sender)
    {
           SetWindowLong(TreeView1->Handle,GWL_STYLE,
                GetWindowLong(TreeView1->Handle,GWL_STYLE) TVS_CHECKBOXES);

    }
    //判断一个节点是否处于Checked状态
    bool  GetNodeChecked(TTreeNode *ANode)
    {
          TVITEM tvItem;
          tvItem.mask = TVIF_HANDLE TVIF_STATE;
          tvItem.hItem = ANode->ItemId;
          tvItem.stateMask = TVIS_STATEIMAGEMASK;
          TreeView_GetItem(ANode->TreeView->Handle, &tvItem);
          return ((BOOL)(tvItem.state >> 12) -1);
    }
    //设置一个节点为Checked状态或者Unchecked状态，由参数IsSetToChecked来确定
    void  SetNodeChecked(TTreeNode *ANode,bool IsSetToChecked)
    {
          TVITEM tvItem;
          tvItem.mask = TVIF_HANDLE TVIF_STATE;
          tvItem.hItem = ANode->ItemId;
          tvItem.stateMask = TVIS_STATEIMAGEMASK;
          tvItem.state = INDEXTOSTATEIMAGEMASK(IsSetToChecked?2:1);
          TreeView_SetItem(ANode->TreeView->Handle, &tvItem);
    }
    void  SetChildChecked(TTreeNode *ANode,bool yn)
    {     // 把它的子孙都置成一样
          int count=ANode->Count;
          SetNodeChecked(ANode,yn);
          if (count!=0)
              for (int i=0;i<count;i++)    // 递归
                 SetChildChecked(ANode->Item[i],yn);
    }
    //    TTreeNode *ClickNode;     //  保存点中的节点
    //    bool      NodeChecked;    //  保存点中的节点checked
    void __fastcall TForm1::TreeView1MouseMove(TObject *Sender,
          TShiftState Shift, int X, int Y)
    {
          ClickNode=TreeView1->GetNodeAt(X,Y);
          if (ClickNode!=NULL)   // 保存原节点的Checked值
             NodeChecked=GetNodeChecked(ClickNode);
    }
    void __fastcall TForm1::TreeView1MouseDown(TObject *Sender,
          TMouseButton Button, TShiftState Shift, int X, int Y)
    {
          if (ClickNode!=NULL)
             if (GetNodeChecked(ClickNode)!=NodeChecked)
                {  // 把它的子孙都置成一样
                   NodeChecked=!NodeChecked;  // 更新它
                   SetChildChecked(ClickNode,NodeChecked);
                }
    }