unit2.pas

ADO三层数据库开发

unit Unit2;

{$WARN SYMBOL_PLATFORM OFF}

interface

uses
  Windows, Messages, SysUtils, Classes, ComServ, ComObj, VCLCom, DataBkr,
  DBClient, Project1_TLB, DB, ADODB, StdVcl, Provider;

type
  TMy2005Class = class(TRemoteDataModule, IMy2005Class)
    ADOConnection1: TADOConnection;
    ADOQuery1: TADOQuery;
    DataSetProvider1: TDataSetProvider;
    procedure ADOConnection1Disconnect(Connection: TADOConnection;
      var EventStatus: TEventStatus);
    procedure ADOConnection1ConnectComplete(Connection: TADOConnection;
      const Error: Error; var EventStatus: TEventStatus);
    procedure RemoteDataModuleCreate(Sender: TObject);
  private
    { Private declarations }
  protected
    class procedure UpdateRegistry(Register: Boolean; const ClassID, ProgID: string); override;
  public
    { Public declarations }
  end;
Const
  SConnectionString       = 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s;'
                                +'Jet OLEDB:Database Password=%s;';
var
i:integer;
implementation

uses Unit1;

{$R *.DFM}
 function setadoaccess(mdbpath:string;passwd:string):string;
begin
mdbpath:=trim(mdbpath);
passwd:=trim(passwd);
result:=format(SConnectionString,[mdbpath,passwd]);
end;
class procedure TMy2005Class.UpdateRegistry(Register: Boolean; const ClassID, ProgID: string);
begin
  if Register then
  begin
    inherited UpdateRegistry(Register, ClassID, ProgID);
    EnableSocketTransport(ClassID);
    EnableWebTransport(ClassID);
  end else
  begin
    DisableSocketTransport(ClassID);
    DisableWebTransport(ClassID);
    inherited UpdateRegistry(Register, ClassID, ProgID);
  end;
end;

procedure TMy2005Class.RemoteDataModuleCreate(Sender: TObject);
begin
ADOConnection1.ConnectionString:=setadoaccess(extractfilepath(paramstr(0))+'tmp.mdb','');
end;

procedure TMy2005Class.ADOConnection1ConnectComplete(Connection: TADOConnection;
  const Error: Error; var EventStatus: TEventStatus);
begin
inc(i);
form1.Label2.Caption:=inttostr(i);
end;

procedure TMy2005Class.ADOConnection1Disconnect(Connection: TADOConnection;
  var EventStatus: TEventStatus);
begin
dec(I);
form1.Label2.Caption:=inttostr(i);
end;

initialization
  TComponentFactory.Create(ComServer, TMy2005Class,
    Class_My2005Class, ciMultiInstance, tmApartment);
end.