unit2.~pas

delphi用于数据库的多线程的实现

unit Unit2;

interface

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

type
  TForm2 = class(TForm)
    DBGrid1: TDBGrid;
    ADOQy: TADOQuery;
    DataSource: TDataSource;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;
  procedure newqueryform(qry:string);
implementation
 uses Unit1;

{$R *.dfm}
type
  TDBthread=class(TThread)
  private
    FADOQy: TADOQuery;
    FDataSource: TDataSource;
    FqueryException:exception;
    procedure Hookupui;
    procedure queryerror;
  protected
    procedure Exceute;override;
  public
    constructor create(q:TADOQuery; d:TDataSource);virtual;
  end;

constructor TDBthread.create(q:TADOQuery;d:TDataSource);
begin
  inherited
  create(true);
  FADOQy:=q;
  FDataSource:=d;
  freeonterminate:=True;
  resume;
end;

procedure TDBthread.Exceute;
begin
  try
     FADOQy.open;
     synchronize(HooKupui);
  except
     FqueryException:= exceptobject as exception;
     synchronize(queryerror);
  end;
end;

procedure TDBthread.Hookupui;
begin
   FDataSource.DataSet:=FADOQy;
end;

procedure TDBthread.queryerror;
begin
  application.ShowException(Fqueryexception);
end;

procedure newqueryform(qry:string);
begin
   with TForm2.Create(application) do
   begin
      with ADOQy do
      begin
         sql.Clear;
         sql.Add(qry);
      end;
      show;
      TDBthread.create(ADOQy,DataSource);
   end;
end;


procedure TForm2.Button1Click(Sender: TObject);
begin
  close;
end;

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action:=cafree;
end;

end.