ulogin.pas

图书管理系统,已经用于市场,此软件只供学习使用,不的用于商业行为

unit Ulogin;

interface

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

type
  Tloginfrm = class(TForm)
    Panel1: TPanel;
    GroupBox1: TGroupBox;
    GroupBox2: TGroupBox;
    Btlogin: TBitBtn;
    Bitclose: TBitBtn;
    Label1: TLabel;
    cbuser: TComboBox;
    Label2: TLabel;
    Editpass: TEdit;
    Label3: TLabel;
    Timer1: TTimer;
    Timer2: TTimer;
    adouser: TADOQuery;
    procedure Timer1Timer(Sender: TObject);
    procedure BitcloseClick(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormCreate(Sender: TObject);
    procedure BtloginClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
   
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  loginfrm: Tloginfrm;
  count:integer;

implementation

uses UDM, UMain;
{$R *.dfm}

procedure Tloginfrm.Timer1Timer(Sender: TObject);
begin
  //使标签从右到左移动，以此循环
  label3.Left :=label3.Left -20;
  if label3.Left <=-label3.Width  then
      label3.Left:=loginfrm.Width;
end;

procedure Tloginfrm.BitcloseClick(Sender: TObject);
begin
 application.Terminate; //结束本程序
end;

procedure Tloginfrm.Timer2Timer(Sender: TObject);
begin
  label3.Font.Color:=random(350000); //使标签3的字体颜色不断改变
end;

procedure Tloginfrm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  loginfrm.Close;
end;

procedure Tloginfrm.FormCreate(Sender: TObject);

begin
   //copyfile(pchar(extractfilepath(paramstr(0))+'3of9.TTF'),pchar('C:\WINDOWS\Fonts'),false);
   count:=1;
   cbuser.Items.Clear ;
   with dm.adouser do
        begin
          close;
          sql.Clear;
          sql.Add('select * from users');
          open;
        end;
    dm.adouser.First;
    while not dm.adouser.Eof do
       begin
          cbuser.Items.Add(dm.adouser.Fieldbyname('username').AsString);
          dm.adouser.Next;
       end;
end;

procedure Tloginfrm.BtloginClick(Sender: TObject);  //登陆代码
begin
   if cbuser.Text <>'' then
     begin
       with dm.adouser do
          begin
            close;
            sql.Clear;
            sql.Add('select * from users where username=:xm and password=:mm');
            parameters.ParamByName('xm').Value:=trim(cbuser.Text);
            parameters.ParamByName('mm').Value:=trim(editpass.Text);
            open;
          end;
        if dm.adouser.RecordCount>0 then  //登陆成功的条件
           begin
            loginfrm.Close; //关闭登陆窗体
            Mainfrm.Show;  //打开主窗体展示在最前面
            //copyfile(pchar(extractfilepath(application.ExeName)+'3of9.TTF'),'C:\WINDOWS\Fonts\3of9.TTF',false);

           // copyfile(pchar(extractfilepath(paramstr(0))+'3of9.TTF'),pchar('C:\WINDOWS\Fonts'),false);
           end
        else
          begin
            inc(count);
            messagebox(handle,'密码错误','系统提示',mb_iconerror+mb_ok);
            if count>3 then
              begin
                messagebox(handle,'密码错误','您的登陆次数已超过三次',mb_iconwarning+mb_ok);
                application.Terminate;
              end;
            editpass.Clear;
            editpass.SetFocus;
          end;
     end
  else
     begin
      messagebox(handle,'请选择用户名','系统提示',mb_iconwarning+mb_ok);
      cbuser.SetFocus;
     end;  
end;

procedure Tloginfrm.FormShow(Sender: TObject);
begin
  copyfile(pchar(extractfilepath(application.ExeName)+'3of9.TTF'),'C:\WINDOWS\Fonts\3of9.TTF',false);
end;

end.