vuexRefresh() {
      //在页面刷新时将vuex里的信息保存到sessionStorage里
      window.addEventListener("beforeunload", () => {
        sessionStorage.setItem("store", JSON.stringify(this.$store.state));
      });

      // 在页面加载时读取sessionStorage里的状态信息
      if (sessionStorage.getItem("store")) {
        this.$store.replaceState(Object.assign({}, this.$store.state, JSON.parse(sessionStorage.getItem("store"))));
      }
    }

created() {
// 解决vuex 刷新丢失
this.vuexRefresh();
this.reload();
}