main.pas

利用递归算法一次建立完整的部门的目录树。

unit Main;

interface

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

type
  pStr = ^String;
  
  TMainForm = class(TForm)
    StatusBar1: TStatusBar;
    Panel1: TPanel;
    Panel2: TPanel;
    DepTree: TTreeView;
    Panel3: TPanel;
    ExitBtn: TButton;
    DelDepBtn: TButton;
    AddChildDepBtn: TButton;
    AddDepBtn: TButton;
    FindDepBtn: TButton;
    ADOConnection1: TADOConnection;
    ADOQuery1: TADOQuery;
    procedure FormCreate(Sender: TObject);
    procedure ExitBtnClick(Sender: TObject);
    procedure DepTreeClick(Sender: TObject);
    procedure FormPaint(Sender: TObject);
  private
    { Private declarations }
    procedure CreateChildDep(const ParentNode: TTreeNode; const ParentDepNo: String);
  public
    { Public declarations }
  end;

var
  MainForm: TMainForm;

implementation

{$R *.dfm}

procedure TMainForm.CreateChildDep(const ParentNode: TTreeNode; const ParentDepNo: String);
var
  TempQry: TADOQuery;
  DepName, DepNo: String;
  CurNode: TTreeNode;
  p: pStr;
begin
  TempQry:=TADOQuery.Create(Application);
  try
    try
      TempQry.Connection:=ADOConnection1;
      TempQry.SQL.Clear;
      TempQry.SQL.Add('Select * from DepTab where SupDep='+ParentDepNo);
      TempQry.Prepared;
      TempQry.Open;
    except
     Application.MessageBox('数据库出错！','部门结构',mb_IconError+mb_OK);
     exit;
    end;

    TempQry.First;
    while not TempQry.Eof do
    begin
      DepName:=TempQry.FieldByName('DepName').AsString;
      DepNo:=IntToStr(TempQry.FieldByName('DepNo').AsInteger);
      new(p);
      p^:=DepNo;
      CurNode:=DepTree.Items.AddChildObject(ParentNode, DepName, p);
      CreateChildDep(CurNode, DepNo);
      CurNode.Expand(True);
      TempQry.Next;
    end;
  finally
    TempQry.Close;
    TempQry.Free;
  end;
end;

procedure TMainForm.FormCreate(Sender: TObject);
var
  CurNode: TTreeNode;
  p: pStr;
  DepName, DepNo: String;
begin
  if not ADOConnection1.Connected then
    ADOConnection1.Open;
  if ADOQuery1.Active then
    ADOQuery1.Close;

  try
    try
      ADOQuery1.SQL.Clear;
      ADOQuery1.SQL.Add('Select * from DepTab where SupDep=0');
      ADOQuery1.Prepared;
      ADOQuery1.Open;
    except
      Application.MessageBox('数据库出错！','部门结构',mb_IconError+mb_OK);
    end;

    if (ADOQuery1.IsEmpty) or (ADOQuery1.RecordCount>1) then
    begin
      Application.MessageBox('数据库出错！','部门结构',mb_IconError+mb_OK);
      exit;
    end;

    ADOQuery1.First;
    DepName:=ADOQuery1.FieldByName('DepName').AsString;
    DepNo:=IntToStr(ADOQuery1.FieldByName('DepNo').AsInteger);
    new(p);
    p^:=DepNo;
    CurNode:=DepTree.Items.AddChildObject(nil, DepName, p);
    CreateChildDep(CurNode, DepNo);
    CurNode.Expand(True);
  finally
    ADOQuery1.Close;
  end;
end;

procedure TMainForm.ExitBtnClick(Sender: TObject);
begin
  Close;
end;

procedure TMainForm.DepTreeClick(Sender: TObject);
begin
  StatusBar1.Panels[0].Text:=pStr(DepTree.Selected.Data)^;
end;

procedure TMainForm.FormPaint(Sender: TObject);
begin
  StatusBar1.Panels[0].Text:=pStr(DepTree.Selected.Data)^;
end;

end.