thinkPHP实现的验证码登录功能示例

<?php  namespace Admin/Controller;  use Think/Controller;  use Think/Verify;  class LoginController extends Controller{    public function login(){      if($_POST){        $obj = new Verify();        if($obj->check(I('post.yanzhengma','','trim'))){          // 注释部分为另外一种从数据库中验证密码的方法          // $data['name'] = I('post.user_name');          // $data['psd'] = I('post.password');          // $row = M('user')->where($data)->find();          $name = I('post.user_name');          $psd = I('post.password');          $str = 'name ="'.$name. '" and tel = "'.$psd.'"';          var_dump($str);          $row = M('user')->where($str)->find();          if($row)            $this->redirect("Index/index");          else            $this->redirect('login','',1,'用户名或密码错误');        }        else{          $this->redirect('login','',1,'验证码错误');        }      }      $this->display();    }    public function verifyImg(){      //设置验证码的宽高字体大小以及验证码的个数，设计其他的参照Think/Verify里面的设置      $config=array(        'imageW'  => 150,        'imageH'  => 40,        'fontSize' => 20,        'length'  => 4      );      $obj = new /Think/Verify($config);      $obj->entry();    }  }

<form action="login" method="post">  <table valign="top" width="50%"> <tr><td colspan="2"><h4 style="letter-spacing:1px;font-size:16px;">RainMan 网站管理后台</h4></td></tr> <tr><td>管理员：</td><td><input type="text" name="user_name" value="" /></td></tr> <tr><td>密    码：</td><td><input type="password" name="password" value="" /></td></tr> <tr><td>验证码：</td>   <td><input type="text" name="yanzhengma" value="" style="width:80px;"/></td>   <td><img src="__URL__/verifyImg" onclick="this.src='__URL__/verifyImg/'+Math.random()" </tr> <tr class="bt" align="center"><td> <input type="submit" value="登陆" /></td><td> <input type="reset" value="重填" /></td></tr>  </table></form>