child_code.pas

一个桌面数据库应用的源码,适合初学数据库编程的新手.

unit Child_Code;

interface

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

type
  Tfrm_Code = class(TForm)
    Panel1: TPanel;
    Label1: TLabel;
    ComboBox1: TComboBox;
    DataSource1: TDataSource;
    Table1: TTable;
    DBNavigator: TDBNavigator;
    DBGrid1: TDBGrid;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure ComboBox1Change(Sender: TObject);
    procedure DataSource1DataChange(Sender: TObject; Field: TField);
    procedure FormActivate(Sender: TObject);
  private
    function GetDBName: String;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frm_Code: Tfrm_Code;

implementation

uses Main;

{$R *.DFM}

function Tfrm_Code.GetDBName:String;
begin
  case ComboBox1.ItemIndex of
  0:begin
      Result:='type.db';
    end;
  1:begin
      Result:='experi.db';
    end;
  end;
end;

procedure Tfrm_Code.FormCreate(Sender: TObject);
begin
  Height:=Constraints.MinHeight;
  Width:=Constraints.MinWidth;
  Panel1.Align:=alTop;
  DBGrid1.Align:=alClient;
  ComboBox1.ItemIndex:=0;
  Table1.DatabaseName:=MainForm.GetExePath+'mdb';
  Table1.TableName:=GetDBName;
  Table1.Open;
end;

procedure Tfrm_Code.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Table1.Close;
  with Mainform do
  begin
//    StatusBar.Panels[1].Text:='代码库已关闭';
    if MDIChildCount=1 then
      StatusBar.Panels[1].Text:='';
  end;
  Action:=caFree;
end;

procedure Tfrm_Code.ComboBox1Change(Sender: TObject);
begin
  Table1.Close;
  Table1.TableName:=GetDBName;
  Table1.Open;
end;

procedure Tfrm_Code.DataSource1DataChange(Sender: TObject; Field: TField);
begin
  FormActivate(Sender);
end;

procedure Tfrm_Code.FormActivate(Sender: TObject);
begin
  MainForm.StatusBar.Panels[1].Text:='代码库纪录导航信息：第'+inttostr(DataSource1.DataSet.RecNo)+'笔纪录-总共'+inttostr(DataSource1.DataSet.RecordCount)+'笔纪录';
end;

end.