router.beforeEach((to, from, next) => {
 if (to.matched.some(record => record.meta.requireAuth)){ // 判斷該路由是否需要登錄權限
 if (token) { // 判斷當前的token是否存在
 next();
 }
 else {
 next({
 path: '/login',
 query: {redirect: to.fullPath} // 將跳轉的路由path作為參數，登錄成功后跳轉到該路由
 })
 }
 }
 else {
 next();
 }
});

{
 path: '/index',
 meta: {
 title: '',
 requireAuth: true, // 添加該字段，表示進入這個路由是需要登錄的
 },
}

if(this.$route.query.redirect){
// let redirect = decodeURIComponent(this.$route.query.redirect);
 let redirect = this.$route.query.redirect;
 this.$router.push(redirect);
}else{
 this.$router.push('/');
 }