Vue.js：TypeError：无法读取未定义的属性“$router”？

Question

Laravel 5.7 和 Vue.js2。我正在使用 JWT Authentication 和 Vuex 来存储我的 LoggedIn 用户信息。当我想在登录后重定向到主页时，$router 给出了这个意外错误。

登录功能：

login()
{
        Axios.post('/api/auth/login',{
          email: this.form.email,
          password: this.form.password
        })
        .then(function(response){

          let token = response.data.access_token;
          let username = response.data.user.name;
          let role = response.data.user.role;

          if(Token.isValid(token))
          {
            localStorage.setItem('token', token);
            localStorage.setItem('username', username);
            localStorage.setItem('role', role);

            this.$router.push({path: '/'});
          }

        })
        .catch(function(error){
          console.log(error)
        })
}

App.js

import Vuex from 'vuex';
import { routes } from './router/routes.js'
Vue.use(VueRouter)
Vue.use(Vuex);

const router = new VueRouter({
    routes,
    mode: 'history'
  })

const app = new Vue({
    el: '#app',
    router,
    components: {
        AppMain
    }
});

Answer 1

你使用这个代码：this.$router.push({path: '/'});在函数上下文中。你可以在https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/thishttps://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this@

中阅读更多关于“this”的信息

要更正错误，请编写以下代码：

login()
{
        let self = this;
        Axios.post('/api/auth/login',{
          email: this.form.email,
          password: this.form.password
        })
        .then(function(response){

          let token = response.data.access_token;
          let username = response.data.user.name;
          let role = response.data.user.role;

          if(Token.isValid(token))
          {
            localStorage.setItem('token', token);
            localStorage.setItem('username', username);
            localStorage.setItem('role', role);

            self.$router.push({path: '/'});
          }

        })
        .catch(function(error){
          console.log(error)
        })
}

我在上下文中将“this”放在了更高的位置。 或者你可以使用箭头功能：

login()
{
        Axios.post('/api/auth/login',{
          email: this.form.email,
          password: this.form.password
        })
        .then((response) => {

          let token = response.data.access_token;
          let username = response.data.user.name;
          let role = response.data.user.role;

          if(Token.isValid(token))
          {
            localStorage.setItem('token', token);
            localStorage.setItem('username', username);
            localStorage.setItem('role', role);

            this.$router.push({path: '/'});
          }

        })
        .catch(function(error){
          console.log(error)
        })
}

你可以在那里阅读箭头函数：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions