public function actionGetCheckNum()
 {
     $phone = Yii::$app->request->get('phone');
     $checkNum = rand(100000, 999999);
     $session = Yii::$app->session;
     if (!isset($session['time'])) {
         $session['time'] = date("Y-m-d H:i:s");
     }
     $session['checkNum'] = $checkNum;
     //将content的值保存在session中
     if (!empty($phone)) {
         if (Users::isExist($phone)) {
             $msg = "已存在的电话号码!";
         } else {
             if (strtotime($session['time']) + 60 < time()) {
                 //将获取的缓存时间转换成时间戳加上60秒后与当前时间比较,小于当前时间即为过期
                 session_destroy();
                 $session->remove('time');
                 $msg = '验证码已过期,请重新获取!';
             } else {
                 $content = "尊敬的学员,您的注册验证码是" . $checkNum . ",此验证码于一分钟后过期,请尽快完成注册,谢谢!【教练系统】";
                 $smsModel = Sms::getInstance(Yii::$app->params['smsUserName'], Yii::$app->params['smsPassword']);
                 $result = $smsModel->pushMt($phone, time(), $content, 0);
                 if ($result == '0') {
                     $msg = '验证码已经发送到手机' . $phone . ',请注意查收。';
                 } else {
                     $msg = "系统错误请联系网站管理员,谢谢";
                 }
             }
         }
     } else {
         $msg = '请输入手机号码!';
     }
     return $msg;
 }