頁面登陸狀態——cookies
cookie操作
this.$cookies.set('key',value,過期時間秒)
this.$cookies.get('key')
this.$cookies.remove('key')
前端注銷
logout(){
//清除cookie
this.$cookies.remove('token')
this.$cookies.remove('username')
//把兩個變量值為空
this.username=''
this.token=''
},