使用 TClientDataSet(1)

本例效果图:

---

代码文件:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    Button2: TButton;
    ClientDataSet1: TClientDataSet;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{本来可以不写代码, 设置四个属性即可}
procedure TForm1.FormCreate(Sender: TObject);
var
  DataFile: string;
begin
  {获取 CodeGear 共享安装的数据文件: country.xml 的路径}
  DataFile := GetEnvironmentVariable('COMMONPROGRAMFILES');   {C:\Program Files\Common Files}
  DataFile := DataFile + '\CodeGear Shared\Data\country.xml'; {country.cds 也可}

  DBGrid1.DataSource := DataSource1;     {DBGrid 需要连接数据源}
  DataSource1.DataSet := ClientDataSet1; {数据源 DataSource 需要连接数据集}
  ClientDataSet1.FileName := DataFile;   {让数据集 ClientDataSet 关联一个数据文件}

  {打开数据集}
  ClientDataSet1.Active := True; //或 ClientDataSet1.Open;
end;

end.

窗体文件:

---

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 251
  ClientWidth = 439
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Panel1: TPanel
    Left = 0
    Top = 0
    Width = 439
    Height = 41
    Align = alTop
    Caption = 'Panel1'
    TabOrder = 0
    object Button1: TButton
      Left = 20
      Top = 8
      Width = 75
      Height = 25
      Caption = 'Button1'
      TabOrder = 0
    end
    object Button2: TButton
      Left = 101
      Top = 8
      Width = 75
      Height = 25
      Caption = 'Button2'
      TabOrder = 1
    end
  end
  object DBGrid1: TDBGrid
    Left = 0
    Top = 41
    Width = 439
    Height = 210
    Align = alClient
    TabOrder = 1
    TitleFont.Charset = DEFAULT_CHARSET
    TitleFont.Color = clWindowText
    TitleFont.Height = -11
    TitleFont.Name = 'Tahoma'
    TitleFont.Style = []
  end
  object DataSource1: TDataSource
    Left = 160
    Top = 104
  end
  object ClientDataSet1: TClientDataSet
    Aggregates = <>
    Params = <>
    Left = 168
    Top = 112
  end
end