TreeView 连接Access数据库立即保存时时更新

【例子介绍】
【相关图片】

【源码结构】

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, DB, DBTables, ComCtrls, Grids, DBGrids, ExtCtrls,
  DBCtrls, Mask;


type
  TForm1 = class(TForm)
    TreeView1: TTreeView;
    ImageList1: TImageList;
    DataSource1: TDataSource;
    DBEdit1: TDBEdit;
    Label1: TLabel;
    Label2: TLabel;
    DBEdit2: TDBEdit;
    Table1: TTable;
    Label3: TLabel;
    DBNavigator1: TDBNavigator;
    Label4: TLabel;
    DBEdit3: TDBEdit;
    DBEdit4: TDBEdit;
    function  GetFieldList: TStringList;
    procedure FormCreate(Sender: TObject);
    procedure TreeView1Change(Sender: TObject; Node: TTreeNode);
    procedure DataSource1StateChange(Sender: TObject);
    procedure Table1AfterInsert(DataSet: TDataSet);
    procedure Table1BeforeDelete(DataSet: TDataSet);
    procedure Table1BeforeEdit(DataSet: TDataSet);
    procedure Table1AfterDelete(DataSet: TDataSet);
    procedure Table1AfterPost(DataSet: TDataSet);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;
  FieldList: TStringList;

implementation
uses TreeFunc;

{$R *.DFM}


function TForm1.GetFieldList: TStringList;
begin
     FieldList.clear;
     FieldList.add(Table1.fieldbyname('Country').asstring);
     FieldList.add(Table1.fieldbyname('city').asstring);
     FieldList.add(Table1.fieldbyname('Company').asstring);
     Result := FieldList;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
     FieldList := TStringList.create;

     TreeView1.items.BeginUpdate;

     Table1.first;
     while not Table1.eof do
     begin
          TreeAddItem(TreeView1, GetFieldList, Table1.getBookmark, false);
          Table1.next;
     end;

     FieldList.clear;
     TreeView1.Alphasort;
     TreeView1.items.Endupdate;

//make first record selected:
     TreeView1.items[2].selected := true;
end;

procedure TForm1.TreeView1Change(Sender: TObject; Node: TTreeNode);
begin
     Datasource1.enabled := Node.data <> nil;
     if DataSource1.enabled then Table1.gotobookmark(node.data);
end;

procedure TForm1.DataSource1StateChange(Sender: TObject);
var
   ItemList: TStringList;
   Node: TTreeNode;
begin
end;

procedure TForm1.Table1AfterInsert(DataSet: TDataSet);
begin
     FieldList.clear;
end;

procedure TForm1.Table1BeforeDelete(DataSet: TDataSet);
begin
     GetFieldList;
end;

procedure TForm1.Table1BeforeEdit(DataSet: TDataSet);
begin
     GetFieldList;
end;

procedure TForm1.Table1AfterDelete(DataSet: TDataSet);
var
   CascadeDeleteLevel: Integer;
begin
     CascadeDeleteLevel := 0;
     TreeDeleteItem(TreeView1, FieldList, CascadeDeleteLevel);
end;

procedure TForm1.Table1AfterPost(DataSet: TDataSet);
begin
     TreeView1.items.beginUpdate;

     if FieldList.count > 0 then TreeDeleteItem(TreeView1, Fieldlist, 0);
     TreeView1.selected := TreeAddItem(TreeView1, GetFieldlist, Table1.getbookmark, True);

     TreeView1.items.endUpdate;
end;

end.