login.pas

这是一个简单的学生管理系统

unit Login;

interface

uses Windows, SysUtils, Classes, Graphics, Forms, Controls, StdCtrls,
  Buttons, ExtCtrls,ADODB,Messages,Dialogs;

type
  TfrmLogin = class(TForm)
    Label1: TLabel;
    edtUserName: TEdit;
    Label2: TLabel;
    edtPassword: TEdit;
    bbtnOK: TBitBtn;
    bbtnCancel: TBitBtn;
    Image1: TImage;
    procedure bbtnOKClick(Sender: TObject);
    procedure bbtnCancelClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmLogin: TfrmLogin;
implementation
uses U_Data,U_main;
{$R *.dfm}

procedure TfrmLogin.bbtnOKClick(Sender: TObject);
var sUserName,sPassword :string;
begin
if datam.usert.Active then
   datam.usert.Close;
sUserName:=trim(edtusername.Text);
sPassword:=trim(edtpassword.Text);
datam.usert.Filter:='id='+''''+sUserName+'''';
datam.usert.Filtered:=true;
datam.usert.Open;
if datam.usert.RecordCount=0 then
  begin
   showmessage('无此用户');
  end
else
 begin
   if trim(datam.usert.FieldByName('passwd').AsString)=sPassword  then
      frmmain.ShowModal
   else
      showmessage('密码错误');
 end;


end;

procedure TfrmLogin.bbtnCancelClick(Sender: TObject);
begin
 if datam.Conn.Connected then
        datam.Conn.Connected:= False;
  application.Terminate ;
end;


end.