{-------------------------------------------------------------------------------  在Delphi 7下Virtual Treeview的簡單使用    http://blog.csdn.net/akof1314 -------------------------------------------------------------------------------} unit Unit1;  interface  uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, VirtualTrees, StdCtrls;  type   TForm1 = class(TForm)     vrtlstrngtrVST: TVirtualStringTree;     btnAddRoot: TButton;     btnAddChildren: TButton;     btnClear: TButton;     edtNumber: TEdit;     grp1: TGroupBox;     procedure FormCreate(Sender: TObject);     procedure btnAddRootClick(Sender: TObject);     procedure btnAddChildrenClick(Sender: TObject);     procedure btnClearClick(Sender: TObject);     procedure vrtlstrngtrVSTInitNode(Sender: TBaseVirtualTree; ParentNode,       Node: PVirtualNode; var InitialStates: TVirtualNodeInitStates);     procedure vrtlstrngtrVSTGetText(Sender: TBaseVirtualTree;       Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;       var CellText: WideString);     procedure vrtlstrngtrVSTFreeNode(Sender: TBaseVirtualTree;       Node: PVirtualNode);   private     { Private declarations }   public     { Public declarations }   end;  var   Form1: TForm1;  implementation  {$R *.dfm} {-------------------------------------------------------------------------------  Description: 定義一個記錄型別，根據所需新增內容 -------------------------------------------------------------------------------} type   PMyRec = ^TMyRec;   TMyRec = record            //記錄自己的節點結構型別     Caption: String;   end; {-------------------------------------------------------------------------------  Description: 建立建立函式 -------------------------------------------------------------------------------} procedure TForm1.FormCreate(Sender: TObject); begin   vrtlstrngtrVST.NodeDataSize := SizeOf(TMyRec);   //設定節點資料空間   vrtlstrngtrVST.RootNodeCount := 20;              //設定初始化節點數 end; {-------------------------------------------------------------------------------  Description: 新增節點 -------------------------------------------------------------------------------} procedure TForm1.btnAddRootClick(Sender: TObject); var   Count: Cardinal; begin   Count := StrToInt(edtNumber.Text);   vrtlstrngtrVST.RootNodeCount := vrtlstrngtrVST.RootNodeCount + Count; end; {-------------------------------------------------------------------------------  Description: 新增子節點 -------------------------------------------------------------------------------} procedure TForm1.btnAddChildrenClick(Sender: TObject); var   Count: Cardinal; begin   with vrtlstrngtrVST do   begin     if Assigned(FocusedNode) then     begin       Count := StrToInt(edtNumber.Text);       ChildCount[FocusedNode] := ChildCount[FocusedNode] + Count;       Expanded[FocusedNode] := True;      //展開節點       InvalidateToBottom(FocusedNode);    //重新整理此節點以下的區域     end;   end; end; {-------------------------------------------------------------------------------  Description: 清除所有節點 -------------------------------------------------------------------------------} procedure TForm1.btnClearClick(Sender: TObject); begin   vrtlstrngtrVST.Clear; end; {-------------------------------------------------------------------------------  Description: 每個節點非同步觸發一次 -------------------------------------------------------------------------------} procedure TForm1.vrtlstrngtrVSTInitNode(Sender: TBaseVirtualTree;   ParentNode, Node: PVirtualNode;   var InitialStates: TVirtualNodeInitStates); var   Data: PMyRec; begin   with Sender do   begin     Data := GetNodeData(Node);     Data.Caption := Format('等級 %d，索引 %d',[GetNodeLevel(Node),Node.Index]);   end; end; {-------------------------------------------------------------------------------  Description: 樹節點顯示的字串資料 -------------------------------------------------------------------------------} procedure TForm1.vrtlstrngtrVSTGetText(Sender: TBaseVirtualTree;   Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;   var CellText: WideString); var   Data: PMyRec; begin   Data := Sender.GetNodeData(Node);   if Assigned(Data) then     CellText := Data.Caption; end; {-------------------------------------------------------------------------------  Description: 釋放節點資料 -------------------------------------------------------------------------------} procedure TForm1.vrtlstrngtrVSTFreeNode(Sender: TBaseVirtualTree;   Node: PVirtualNode); var   Data: PMyRec; begin   Data := Sender.GetNodeData(Node);   Finalize(Data^); end;  end.