在DELPHI中用TreeView控件从数据库中动态装载信息

1.PInfo表结构
ID VARCHAR(50)
FullName VARCHAR(50)
ParentID VARCHAR(50)

2.Unit文件
unit Info;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ComCtrls, DB, ADODB;

type
  PNodeInfo=^TNodeInfo;
  TNodeInfo=record
    ID:string;
    FullName:string;
  end;

  TfmInfo = class(TForm)
    TreeView1: TTreeView;
    btnShowInfo: TButton;
    ADOQuery1: TADOQuery;
    ADOConnection1: TADOConnection;
    procedure CreateChildTree(ParentNode: TTreeNode);
    procedure btnShowInfoClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  fmInfo: TfmInfo;

implementation

{$R *.dfm}

//创建子树
procedure TfmInfo.CreateChildTree(ParentNode: TTreeNode);
var
  Query:TADOQuery;
  ChildNode:TTreeNode; //孩子结点
  ChildNodeInfo:PNodeInfo; //孩子结点信息
begin
  Query:=TADOQuery.Create(nil);
  with Query do
  begin
    Connection:=ADOConnection1;
    SQL.Add('SELECT ID,FullName FROM PInfo WHERE ParentID = '''+PNodeInfo(ParentNode.Data)^.ID+''''); //获取孩子结点信息
    Open;

    while not Eof do
    begin
      New(ChildNodeInfo);
      ChildNodeInfo^.ID:=FieldByName('ID').AsString;
      ChildNodeInfo^.FullName:=FieldByName('FullName').AsString;

      ChildNode:=TreeView1.Items.AddChildObject(ParentNode,(ChildNodeInfo^.ID+ChildNodeInfo^.FullName),ChildNodeInfo); //添加孩子结点，并关联孩子结点信息

      CreateChildTree(ChildNode); //进行递归

      Next;
    end;

    Close;
  end;
end;

procedure TfmInfo.btnShowInfoClick(Sender: TObject);
var
  BootNode:TTreeNode; //根结点
  BootNodeInfo:PNodeInfo; //根结点信息
begin
  with ADOQuery1 do
  begin
    SQL.Clear;
    SQL.Add('SELECT ID,FullName FROM PInfo WHERE ParentID IS NULL'); //获取根结点信息
    Open;

    New(BootNodeInfo);
    BootNodeInfo^.ID:=FieldByName('ID').AsString;
    BootNodeInfo^.FullName:=FieldByName('FullName').AsString;

    TreeView1.Items.Clear;
    BootNode:=TreeView1.Items.AddChildObject(nil,(BootNodeInfo^.ID+BootNodeInfo^.FullName),BootNodeInfo); //添加根结点，并关联根结点信息

    Close;
  end;

  CreateChildTree(BootNode); //创建子树
  TreeView1.FullExpand; //展开所有树结点
end;

end.