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用递归方式向treeview中生成树 望指教解决方法

分类: IT文章 • 2024-02-11 08:49:49
用递归方式向treeview中生成树 望指教
定义了AnsiString array[13];在该数组中了存取了从数据库查询的数据，每个数组元素储存查询到的3个数据
C/C++ code

void AddTree( AnsiString ParentID,TTreeNode *pNode )
{

    AnsiString str = "PDMObject_ID" + ParentID;
    TTreeNode *Node = new TTreeNode();//(1) E2285 Could not find a match for 'TTreeNode::TTreeNode()'
    for( int i = 0 ; i<13 ; i++ )
    if(pNode == NULL)     //处理主节点
    {
        Node->Text = array[i];
        TreeView1->Items->Add(Node);//(2) E2451 Undefined symbol 'TreeView1'
        AddTree(str,Node);
    }
    else                  //处理子节点
    {
        Node->Text = array[i];
        pNode->Item->Add(Node);//(3) E2316 'Add' is not a member of 'TTreeNode'
        AddTree(str,Node);
    }
}

在FormCreate事件中调用AddTree(0,(TTreeNode)NULL); 报错：
//（4） E2459 VCL style classes must be constructed using operator new
(2)中把TTreeView *TreeView1;的声明从__published:移到public:还是报错

------解决方案--------------------
很乱，还不如你说清楚你要实现什么，俺重新给你写一个例子
------解决方案--------------------
C/C++ code

  TTreeNode *root,*node,*node1;
  TreeView1->Items->Clear() ;
  sprintf(ls_select2,"select * from IMSDB2006..Holiday where sjdm=''") ;
  DM->Query->Close() ;
  DM->Query->SQL->Clear() ;
  DM->Query->SQL->Add(ls_select2) ;
  DM->Query->Open() ;
  root=new TTreeNode(TreeView1->Items) ;
  root=TreeView1->Items->AddChild(NULL,"全部") ;
  fd=DM->Query->FindFirst() ;
  while(fd)
  {
   char ls_select1[1000] ;
   node1=new TTreeNode(TreeView1->Items) ;
   AnsiString  ls_viewmc =DM->Query->FieldByName("HolidayCode")->AsString  ;
   node1=TreeView1->Items->AddChild(root,ls_viewmc) ;
   sprintf(ls_select1,"select * from Holiday where sjdm='%s'",ls_viewmc.c_str()) ;
   DM->Query1->Close() ;
   DM->Query1->SQL->Clear() ;
   DM->Query1->SQL->Add(ls_select1) ;
   DM->Query1->Open() ;
   bool fd1=DM->Query1->FindFirst() ;
   while(fd1)
   {
     node=new TTreeNode(TreeView1->Items) ;
     AnsiString ls_childmc = DM->Query->FieldByName("HolidayCode")->AsString ;
     node=TreeView1->Items->AddChild(node1,ls_childmc) ;
     fd1=DM->Query1->FindNext() ;
   }
   fd=DM->Query->FindNext() ;
  }

------解决方案--------------------
我没有写代码测试，不过楼主的代码里面for循环那部分，里面递归肯定是死循环呀，没有结束条件，一直递归
改成
C/C++ code
void AddTree( AnsiString ParentID,TTreeNode *pNode )
{

    AnsiString str = "PDMObject_ID" + ParentID;
    TTreeNode *Node ;//= new TTreeNode(NULL);//(1) E2285 Could not find a match for 'TTreeNode::TTreeNode()'
    static int i = 0;
    if(pNode == NULL&&i<13)     //处理主节点
    {

        Node = tv1->Items->AddChild(NULL,array[i]);//(2) E2451 Undefined symbol 'TreeView1'
        i++;
        AddTree(str,Node);

    }
    else                  //处理子节点
    {

        Node = tv1->Items->AddChild(pNode,array[i]);//(3) E2316 'Add' is not a member of 'TTreeNode'
        i++;
        AddTree(str,Node);
    }
}

------解决方案--------------------
不太清楚，我这有个例子，看看是不是你想要的,其中ShowId是当前想要显示的节点，ParentId是当前显示节点的父节点，ShowName 显示节点的名称
C/C++ code

    tv->Items->Clear();
    if( pAQry->Active )
        pAQry->Active = false;
    pAQry->SQL->Text = "select ShowId,ParentId,ShowName from ShowTree order by ShowId asc";
    try
    {
        pAQry->Active = true;
    }
    catch(...)
    {
        MessageBox( this->Handle,"无法与数据库连接!","系统提示",MB_OK | MB_ICONERROR );
        return false;
    }
    TTreeNode *ParentNode;
    try
    {
        for( pAQry->First(); !pAQry->Eof; pAQry->Next() )
        {
            if( pAQry->FieldByName("ParentId")->AsInteger == 0 )
                tv->Items->Add(NULL,pAQry->FieldByName("ShowName")->AsString.Trim());
            else
            {
                ParentNode = tv->Items->Item[pAQry->FieldByName("ParentId")->AsInteger-1];
                tv->Items->AddChild(ParentNode,pAQry->FieldByName("ShowName")->AsString.Trim());
            }
        }
    }
    catch(...)
    {
        MessageBox( this->Handle,"节点生成失败!","系统提示",MB_OK | MB_ICONERROR );
        return false;
    }
    pAQry->Active = false;

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