ufrmlogin.pas

本文件采用了c/s结构的分布式应用系统

unit ufrmlogin;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TfrmLogin = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    edtusername: TEdit;
    Label3: TLabel;
    edtpassword: TEdit;
    btnOk: TButton;
    btnCancel: TButton;
    Label4: TLabel;
    procedure btnOkClick(Sender: TObject);
    procedure btnCancelClick(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmLogin: TfrmLogin;
  flag:boolean;

implementation

uses udmclient, UfrmMain;

{$R *.dfm}

procedure TfrmLogin.btnOkClick(Sender: TObject);
var
  username,password:string;
begin
  username:=edtusername.Text; //用户名
  password:=edtpassword.Text; //密码
  try
    dmclient.cdsLogin.Active:=false;
   { dmclient.cdsLogin.CommandText:='select *from systemusers'+
    '  where username=:username and password=:password'; }
    //像应用程序服务器传递参数值，以便进行查询
    dmclient.cdsLogin.Params.ParamByName('username').Value:=username;
    dmclient.cdsLogin.Params.ParamByName('password').Value:=password;
    dmclient.cdsLogin.Open;
    //查到唯一用户
    if dmclient.cdsLogin.RecordCount=1 then
    begin
      //取得用户权限 ，变量authorization是在主窗体frmMain中申明的全局变量
      frmmain.authorization:=dmclient.cdsLogin.fieldbyname('authorization').Value;
      flag:=true;  //设置标志
      close;    //关闭窗体以便将控制权交给其他窗体
    end
    else
    begin
      flag:=false;
      messagedlg('用户验证失败',mterror,[mbok],0);
      exit;
    end;
  except
  on  e:exception do
  begin
  messagedlg('错误：'+e.Message,mterror,[mbok],0);
  exit;
  end;
  end;

end;

procedure TfrmLogin.btnCancelClick(Sender: TObject);
begin
 flag:=false;
 close;
end;

procedure TfrmLogin.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  if flag=false then
begin
  dmclient.cdsLogin.Close;
  dmclient.DCOMConnSvr.Connected:=false;
end;
end;

end.