router.beforeEach(async(to, from, next) => {

      // 进度条开始

      NProgress.start()

      // 确认用户是否已登录（获取它的token值，这里的getToken()是封装好的一个方法）

      const hasToken = getToken()

      if (hasToken) {//如果有token，说明是登录状态

        if (to.path === '/login') {//路由是/login页，那么直接跳转到首页

          next({ path: '/' })

          NProgress.done()  //进度条结束

        } else {//如果不是登录页

          // 确定用户是否已通过getInfo获得其权限角色

          const hasRoles = store.getters.roles && store.getters.roles.length > 0

          if (hasRoles) {//如果通过角色权限，继续访问

            next()

          } else {//如果没有通过角色权限

            // alert('没有role')

            console.log('获取角色')

            try {

              // get user info

              // note: roles must be a object array! such as: ['admin'] or ,['developer','editor']

              const { roles } = await store.dispatch('user/getInfo')

              // generate accessible routes map based on roles

              const accessRoutes = await store.dispatch('permission/generateRoutes', roles)

              // dynamically add accessible routes

              router.addRoutes(accessRoutes)

              // hack method to ensure that addRoutes is complete

              // set the replace: true, so the navigation will not leave a history record

              next({ ...to, replace: true })

            } catch (error) {

              // remove token and go to login page to re-login

              await store.dispatch('user/resetToken')

              Message.error(error || 'Has Error')

              next(`/login?redirect=${to.path}`)

              NProgress.done()

            }

          }

        }

      } else {//如果没有token

        /* has no token*/

        // alert('没有token to.path=' + to.path)

        if (whiteList.indexOf(to.path) !== -1) {//白名单中有的路由，可以继续访问

          // in the free login whitelist, go directly

          next()

        } else {//否则，白名单中没有的路由，跳回首页

          // other pages that do not have permission to access are redirected to the login page.

          next(`/login?redirect=${to.path}`)

          NProgress.done()

        }

      }

    })