使用thinkphp3.2中的验证码功能

     public function code()
{
    $Verify = new Verify();
    $Verify->fontSize = 20;
    $Verify->length   = 4;
    $Verify->useNoise = false;
    $Verify->entry();
}

function do_login(){
            //获取用户名和密码等。和数据库中比对，有该用户允许登录否则输出错误页面
            $username=$_POST[‘username‘];
            $password=$_POST[‘password‘];
            $code=$_POST[‘code‘];
            $verify = new \Think\Verify();
            $r=$verify->check($code, ‘‘);
            if(!$r){
                $this->error(‘验证码错误！‘);
            }
            $m=M(‘User‘);
            $where[‘username‘]=$username;
            $where[‘password‘]=$password;
            $i=$m->where($where)->count();
            if($i>0){
                $this->redirect(‘User/index‘);
            }else{
                $this->error(‘该用户不存在‘);
            }
        }