text: var vm = new Vue({
      el: '#app',
      data: {
          host: host,
  
          error_name: false,
          error_password: false,
          error_check_password: false,
          error_phone: false,
          error_allow: false,
          error_image_code: false,
          error_sms_code: false,
          error_name_message: '',
          error_image_code_message: '',
          error_phone_message: '',
          error_sms_code_message: '',
  
          image_code_id: '', // 图片验证码id
          image_code_url: '',
  
          sms_code_tip: '获取短信验证码',
          sending_flag: false, // 正在发送短信标志
  
          username: '',
          password: '',
          password2: '',
          mobile: '', 
          image_code: '',
          sms_code: '',
          allow: false
      },
      mounted: function(){
          this.generate_image_code();
      },
      methods: {
          // 生成uuid
          generate_uuid: function(){
              var d = new Date().getTime();
              if(window.performance && typeof window.performance.now === "function"){
                  d += performance.now(); //use high-precision timer if available
              }
              var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
                  var r = (d + Math.random()*16)%16 | 0;
                  d = Math.floor(d/16);
                  return (c =='x' ? r : (r&0x3|0x8)).toString(16);
              });
              return uuid;
          },
          // 生成一个图片验证码的编号，并设置页面中图片验证码img标签的src属性
          generate_image_code: function(){
              // 生成一个编号
              // 严格一点的使用uuid保证编号唯一， 不是很严谨的情况下，也可以使用时间戳
              this.image_code_id = this.generate_uuid();
  
              // 设置页面中图片验证码img标签的src属性
              this.image_code_url = this.host + "/image_codes/" + this.image_code_id + "/";
          },
          check_username: function (){
              var len = this.username.length;
              if(len<5||len>20) {
                  this.error_name_message = '请输入5-20个字符的用户名';
                  this.error_name = true;
              } else {
                  this.error_name = false;
              }
  
          },
          check_pwd: function (){
              var len = this.password.length;
              if(len<8||len>20){
                  this.error_password = true;
              } else {
                  this.error_password = false;
              }        
          },
          check_cpwd: function (){
              if(this.password!=this.password2) {
                  this.error_check_password = true;
              } else {
                  this.error_check_password = false;
              }        
          },
          check_phone: function (){
              var re = /^1[345789]\d{9}$/;
              if(re.test(this.mobile)) {
                  this.error_phone = false;
              } else {
                  this.error_phone_message = '您输入的手机号格式不正确';
                  this.error_phone = true;
              }
  
          },
          check_image_code: function (){
              if(!this.image_code) {
                  this.error_image_code_message = '请填写图片验证码';
                  this.error_image_code = true;
              } else {
                  this.error_image_code = false;
              }    
          },
          check_sms_code: function(){
              if(!this.sms_code){
                  this.error_sms_code_message = '请填写短信验证码';
                  this.error_sms_code = true;
              } else {
                  this.error_sms_code = false;
              }
          },
          check_allow: function(){
              if(!this.allow) {
                  this.error_allow = true;
              } else {
                  this.error_allow = false;
              }
          },
          // 发送手机短信验证码
          send_sms_code: function(){
              if (this.sending_flag == true) {
                  return;
              } 
              this.sending_flag = true;
  
              // 校验参数，保证输入框有数据填写
              this.check_phone();
              this.check_image_code();
  
              if (this.error_phone == true || this.error_image_code == true) {
                  this.sending_flag = false;
                  return;
              }
  
              // 向后端接口发送请求，让后端发送短信验证码
              axios.get(this.host + '/sms_codes/' + this.mobile + '/?text=' + this.image_code+'&image_code_id='+ this.image_code_id, {
                      responseType: 'json'
                  })
                  .then(response => {
                      // 表示后端发送短信成功
                      // 倒计时60秒，60秒后允许用户再次点击发送短信验证码的按钮
                      var num = 60;
                      // 设置一个计时器
                      var t = setInterval(() => {
                          if (num == 1) {
                              // 如果计时器到最后, 清除计时器对象
                              clearInterval(t);
                              // 将点击获取验证码的按钮展示的文本回复成原始文本
                              this.sms_code_tip = '获取短信验证码';
                              // 将点击按钮的onclick事件函数恢复回去
                              this.sending_flag = false;
                          } else {
                              num -= 1;
                              // 展示倒计时信息
                              this.sms_code_tip = num + '秒';
                          }
                      }, 1000, 60)
                  })
                  .catch(error => {
                      if (error.response.status == 400) {
                          this.error_image_code_message = '图片验证码有误';
                          this.error_image_code = true;
                          this.generate_image_code();
                      } else {
                          console.log(error.response.data);
                      }
                      this.sending_flag = false;
                  })
          },
          on_submit: function(){
              this.check_username();
              this.check_pwd();
              this.check_cpwd();
              this.check_phone();
              this.check_sms_code();
              this.check_allow();
  
              if(this.error_name == false && this.error_password == false && this.error_check_password == false
                  && this.error_phone == false && this.error_sms_code == false && this.error_allow == false) {
                  axios.post(this.host + '/users/', {
                          username: this.username,
                          password: this.password,
                          password2: this.password2,
                          mobile: this.mobile,
                          sms_code: this.sms_code,
                          allow: this.allow.toString()
                      }, {
                          responseType: 'json'
                      })
                      .then(response => {
                          console.log(response.data);
                          sessionStorage.clear();
                          localStorage.clear();
                          localStorage.token = response.data.token;
                          localStorage.username = response.data.username;
                          localStorage.user_id = response.data.id;
                          location.href = '/index.html';
                      })
                      .catch(error=> {
                          if (error.response.status == 400) {
                              if ('non_field_errors' in error.response.data) {
                                  this.error_sms_code_message = error.response.data.non_field_errors[0];
                              } else {
                                  this.error_sms_code_message = '数据有误';
                              }
                              this.error_sms_code = true;
                          } else {
                              console.log(error.response.data);
                          }
                      })
              }
          }
      }
  });
  