frm_pws.pas

DLL做登录窗体演示Delphi源码,dll开发和调用

UNIT frm_pws;

INTERFACE

USES
  Windows, SysUtils, Controls, Forms,
   DB, ADODB, Classes, StdCtrls;

TYPE
  Tfrmpws = CLASS(TForm)
    Label1:TLabel;
    Edit1:TEdit;
    Label2:TLabel;
    Edit2:TEdit;
    Button1:TButton;
    Button2:TButton;
    ADOQuery1:TADOQuery;
    PROCEDURE Button1Click(Sender:TObject);
    PROCEDURE Button2Click(Sender:TObject);
  PRIVATE
    { Private declarations }
  PUBLIC
    { Public declarations }
  END;

VAR
  frmpws            :Tfrmpws;
  logincount        :integer;
IMPLEMENTATION

{$R *.dfm}

PROCEDURE Tfrmpws.Button1Click(Sender:TObject);
VAR
  sql               :STRING;
BEGIN
  sql :=
    'select * from pws ' +
    'where user="' + edit1.Text + '" ' +
    'and pwd="' + edit2.Text + '"';

  ADOQuery1.SQL.Text := sql;
  ADOQuery1.Active := true;
  inc(logincount);

  IF (logincount > 4) THEN
    self.ModalResult := mrcancel
  ELSE
    BEGIN
      IF NOT ADOQuery1.IsEmpty THEN
        BEGIN
          ModalResult := mrok;
          ADOQuery1.Active := false;
        END
      ELSE
        BEGIN
          edit1.Text := '';
          edit2.text := '';
        END;
    END;
END;

PROCEDURE Tfrmpws.Button2Click(Sender:TObject);
BEGIN
  ModalResult := mrcancel;
END;

END.