unit1.~pas

一个DELPHI做的通过数据库来对树的操作 包括创建 添加 删除 用到递归运算

unit Unit1;

interface

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

type
   TNodeData = record
    Index : string;
    Caption : string;
    end;
    PNodeData = ^TNodeData;
  TForm1 = class(TForm)
    ADOConnection1: TADOConnection;
    ADOQuery1: TADOQuery;
    Panel1: TPanel;
    ListBox1: TListBox;
    TreeView1: TTreeView;
    GroupBox1: TGroupBox;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure TreeView1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure FormShow(Sender: TObject);

  private
    { Private declarations }
  public
    { Public declarations }
    procedure ShowTree(Node : TTreeNode;PN : PNodeData);
    procedure Del(Node : TTreeNode;PN : PNodeData);
  end;

var
  Form1: TForm1;
  ptr : PNodeData;
implementation


{$R *.dfm}

procedure TForm1.ShowTree(Node : TTreeNode;PN : PNodeData);
var
DQuery : TADOQuery;    //动态创建;
tNode : TTreeNode;
pNode : PNodeData;
begin
try
  DQuery := TADOQuery.Create(nil);
  DQuery.Connection := form1.ADOConnection1;
  DQuery.SQL.Text := 'select * from BM where ltrim(rtrim(father)) =  ' + ''  +(PN^.Index)+  '';
  if DQuery.Active then
  DQuery.Close;
  DQuery.Open;
  while DQuery.Eof = false do
  begin
   new(pNode);
   pNode^.Caption := DQuery.Fields[1].AsString;
   pNode^.Index := DQuery.Fields[0].AsString;
   tNode := form1.TreeView1.Items.AddChildObject(Node,pNode^.Caption,pNode);
   form1.ShowTree(tNode,pNode);
   form1.ListBox1.AddItem(pNode^.Caption,tNode);
   DQuery.Next;
  end;
except

end;

end;

procedure TForm1.Del(Node : TTreeNode;PN : PNodeData);
begin

end;

procedure TForm1.Button1Click(Sender: TObject);
var
Node : TTreeNode;
begin
form1.TreeView1.Items.Clear;
form1.ListBox1.Clear;
new(ptr);
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('select f_bh,f_name from BM where ltrim(rtrim(father)) = ' + '  00  ');
form1.ADOQuery1.Open;
ptr^.Index := trim(form1.ADOQuery1.Fields[0].AsString);
ptr^.Caption := trim(form1.ADOQuery1.Fields[1].AsString);
Node := form1.TreeView1.Items.AddObject(nil,form1.ADOQuery1.Fields[1].AsString,ptr);
form1.ShowTree(Node,ptr);
form1.ListBox1.AddItem(ptr^.Caption,Node);
form1.TreeView1.FullExpand;
end;

procedure TForm1.TreeView1Click(Sender: TObject);
var
click : PNodeData;
begin
click := PNodeData(form1.TreeView1.Selected.Data);
form1.Edit1.Text := click^.Caption;
form1.Edit2.Text := click^.Index;

end;

procedure TForm1.Button2Click(Sender: TObject);
var
have : boolean;
PTree,pNode : PNodeData;
Node : TTreeNode;
begin
//new(PTree);
have := false;
new(pNode);
pNode^.Caption := form1.Edit1.Text;
pNOde^.Index := form1.Edit2.Text;
//Node := form1.TreeView1.Items.AddChildObject(form1.TreeView1.Selected,form1.Edit1.Text,PTree);
PTree := PNodeData(form1.TreeView1.Selected.Data);
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('select f_bh from BM');
form1.ADOQuery1.Open;
while not form1.ADOQuery1.Eof do
begin
if (trim(form1.ADOQuery1.Fields[0].AsString) = form1.Edit2.Text) then
    begin
    have := true;
    break;
    end
else
form1.ADOQuery1.Next;
end;
if have = false  then
begin
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('insert into BM(F_BH,F_NAME,FATHER) values('''+form1.Edit2.Text+''','''+form1.Edit1.Text+''',''' +PTree^.Index+ ''')' );

form1.ADOQuery1.ExecSQL;
Node := form1.TreeView1.Items.AddChildObject(form1.TreeView1.Selected,form1.Edit1.Text,PTree);
end
else showmessage('编号不能相同!');
end;

procedure TForm1.Button3Click(Sender: TObject);
var

PTree : PNodeData;
begin

PTree := PNodeData(form1.TreeView1.Selected.Data);
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('update BM set f_name = ''' + form1.Edit1.Text + '''  where  f_bh  =   ''' + Ptree^.Index+ '''');
//form1.ADOQuery1.Open;
form1.ADOQuery1.ExecSQL;
form1.TreeView1.Selected.Text := form1.Edit1.Text;
end;

procedure TForm1.Button4Click(Sender: TObject);
var
PTree : PNodeData;
TNode : TTreeNode;
begin
TNode := form1.TreeView1.Selected;
PTree := PNodeData(form1.TreeView1.Selected.Data);
while TNode.HasChildren do
begin
TNode.DeleteChildren;
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('delete from BM where FATHER = ''' + PTree^.Index+'''');
form1.ADOQuery1.ExecSQL;
end;
form1.TreeView1.Items.Delete(TNode);
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('delete from BM where f_bh = ''' + PTree^.Index+'''');
form1.ADOQuery1.ExecSQL;
end;

procedure TForm1.FormShow(Sender: TObject);
var
Node : TTreeNode;
begin
form1.TreeView1.Items.Clear;
form1.ListBox1.Clear;
new(ptr);
form1.ADOQuery1.Close;
form1.ADOQuery1.SQL.Clear;
form1.ADOQuery1.SQL.Add('select f_bh,f_name from BM where ltrim(rtrim(father)) = ' + '  00  ');
form1.ADOQuery1.Open;
ptr^.Index := trim(form1.ADOQuery1.Fields[0].AsString);
ptr^.Caption := trim(form1.ADOQuery1.Fields[1].AsString);
Node := form1.TreeView1.Items.AddObject(nil,form1.ADOQuery1.Fields[1].AsString,ptr);
form1.ShowTree(Node,ptr);
form1.ListBox1.AddItem(ptr^.Caption,Node);
form1.TreeView1.FullExpand;
end;


end.