unit UnPwd;

interface

uses Windows, SysUtils, Classes, Graphics, Forms, Controls, StdCtrls,
  Buttons;

type
  Tlogin = class(TForm)
    Label1: TLabel;
    edtusername: TEdit;
    edtpassword: TEdit;
    Label2: TLabel;
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    procedure SpeedButton1Click(Sender: TObject);
    procedure SpeedButton2Click(Sender: TObject);
   // procedure SpeedButton2Click(Sender: TObject);
  private
    { Private declarations }
  public
     function init:boolean;
    { Public declarations }
  end;

var
  login: Tlogin;

implementation

uses UnDB, UnStudent;

{$R *.dfm}

function Tlogin.init; //初始化
begin
  init:=false;
  if Application.FindComponent('login')=nil then
     Application.CreateForm(Tlogin,login);
  init:=true;
end;

procedure Tlogin.SpeedButton1Click(Sender: TObject);
var
  {用戶名,密碼}
  strUserName,strPassWord:string;
begin
  strUserName:=trim(edtusername.Text);
  strPassWord:=trim(edtpassword.Text);
  // 用戶輸入控制
  if (length(strusername)=0) or (length(strpassword)=0) then
  begin
    //Showmessage('用戶名或密碼長度不能為空!');
    edtusername.SetFocus;
    exit;
  end;

  with DataModule1 do
  begin
  //打開數據庫連接
    if not ADOCN.Connected then
       ADOCN.Open;
       //設置SQL查詢
       with ADOQY do
       begin
         close;
         SQL.clear;
         SQL.add('select * from user_Info where user_PWD=:username and user_Des=:password');
         parameters[0].value:=strusername;
         parameters[1].value:=strpassword;
         open;

         //驗證用戶和密碼
         if recordcount<=0 then
         begin
           //showmessage('用戶名或密碼錯誤!');
           EdtUserName.SetFocus;
           Exit;
         end
         else
         begin
           //調用主界界面
           if fm_ClassStudent.init then
           fm_ClassStudent.Show;
           login.Hide;
           Exit;
         end;
       end;
   end;
 end;  
procedure Tlogin.SpeedButton2Click(Sender: TObject);
begin
  Application.Terminate;//結束程序，回收所有資源
end;

end.