查询数据库中的表建个进度条

查询数据库中的表建个进度条

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jianguobu 于 2004-6-19 9:09:15 加贴在 DELPHI ←返回版面：

这段代码不是我自己写的,呵呵,是李维书上的.
直接编译附件里的工程就可以看到效果了.
unit fDemoMain;

interface

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

type
  TForm1 = class(TForm)
    ADOConnection1: TADOConnection;
    ADODataSet1: TADODataSet;
    DataSource1: TDataSource;
    DBNavigator1: TDBNavigator;
    DBGrid1: TDBGrid;
    ADOCommand1: TADOCommand;
    ProgressBar1: TProgressBar;
    Button1: TButton;
    Button2: TButton;
    procedure FormActivate(Sender: TObject);
    procedure ADODataSet1FetchProgress(DataSet: TCustomADODataSet;
      Progress, MaxProgress: Integer; var EventStatus: TEventStatus);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure ADODataSet1FetchComplete(DataSet: TCustomADODataSet;
      const Error: Error; var EventStatus: TEventStatus);
  private
    { Private declarations }
    lStart : Longint;
    lEnd : Longint;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormActivate(Sender: TObject);
var
  sRecNo : String;
begin
  ProgressBar1.Max := ADOCommand1.Execute.Fields.Item[0].Value;
  sRecNo := IntToStr(ProgressBar1.Max);
  Self.Caption := '共有' + sRecNo + ' 笔资料';
end;

procedure TForm1.ADODataSet1FetchProgress(DataSet: TCustomADODataSet;
  Progress, MaxProgress: Integer; var EventStatus: TEventStatus);
begin
  ProgressBar1.Position := Progress;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  try
    ADODataSet1.Active := False;
    ADODataSet1.ExecuteOptions := [eoAsyncFetchNonBlocking];
  finally
    lStart := GetTickCount;
    ADODataSet1.Active := True;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  try
    ADODataSet1.Active := False;
    ADODataSet1.ExecuteOptions := [eoAsyncFetch];
  finally
    lStart := GetTickCount;
    ADODataSet1.Active := True;
  end;
end;

procedure TForm1.ADODataSet1FetchComplete(DataSet: TCustomADODataSet;
  const Error: Error; var EventStatus: TEventStatus);
begin
  lEnd := GetTickCount;
  ShowMessage('总共花了' + FloatToStr((lEnd - lStart) / 1000.0) + '秒');
end;

end.