unit1.pas

DLL做登录窗体演示Delphi源码,dll开发和调用

UNIT Unit1;

INTERFACE

USES
  Windows,
  Messages,
  SysUtils,
  Variants,
  Classes,
  Graphics,
  Controls,
  Forms,
  Dialogs,
  StdCtrls,
  ComObj,
  DB,
  ADODB;

TYPE
  TForm1 = CLASS(TForm)
    Button1:TButton;
    Button2:TButton;
    ADOQuery1:TADOQuery;
    PROCEDURE Button1Click(Sender:TObject);
    PROCEDURE Button2Click(Sender:TObject);
  PRIVATE
    { Private declarations }
  PUBLIC
    { Public declarations }
  END;
CONST
  cnnstr            = 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=PWS.mdb;Jet OLEDB:Database Password=@1$2^3*5';

VAR
  Form1             :TForm1;

PROCEDURE setCNN(cnn:STRING); stdcall; external 'pws.dll';
FUNCTION checkpwd:boolean; stdcall; external 'pws.dll';

IMPLEMENTATION

{$R *.dfm}

PROCEDURE TForm1.Button1Click(Sender:TObject);
VAR
  CreateAccess      :OleVariant;
BEGIN
  IF fileexists('PWS.mdb') THEN
    deletefile('PWS.mdb');
  TRY
    CreateAccess := CreateOleObject('ADOX.Catalog');
    CreateAccess.Create(cnnstr);
  EXCEPT
    //
  END;

  WITH ADOQuery1 DO
    BEGIN
      ConnectionString := cnnstr;
      close;
      sql.clear;
      sql.add('create table [pws]([user] char(20),[pwd] char(20))');
      ADOQuery1.ExecSQL;

      sql.clear;
      sql.add('insert into [pws] values("a","b")');
      ADOQuery1.ExecSQL;

      close;
    END;
END;

PROCEDURE TForm1.Button2Click(Sender:TObject);
BEGIN
  setCNN(cnnstr);
  IF checkpwd THEN
    showmessage('OK')
  ELSE
    showmessage('NO');
END;

END.