监听本地储存变化

 var orignalSetItem = localStorage.setItem;

    localStorage.setItem = function(key, newValue) {

      var setItemEvent = new Event("setItemEvent");

      setItemEvent.key = key;

      setItemEvent.newValue = newValue;

      window.dispatchEvent(setItemEvent);

      orignalSetItem.apply(this, arguments);

    };

    var that = this;

    window.addEventListener("setItemEvent", function(e) {

      if (e.key == "gid") {

        var _this = localStorage.getItem("gid");

        if (_this != e.newValue) {//判断上条数据的gid与当前数据gid是否发生变化

          that.$http({

            url: "/api/message/list",

            data: {

              list_type: "new",

              page_size: 1

            },

            success: result => {

              result.data.list[0].avatar = result.data.list[0].user_avatar||that.getAvatar((Math.abs(crc32.str(result.data.list[0].gid)) % 5) + 1);

              that.newdata = result.data.list[0];

              console.log(that.newdata);

              that.List.push({

                id: ++that.currentId,

                avatar: that.newdata.avatar,

                msg: that.newdata.content,

                time: Math.random() * 2 + 3,

                type: MESSAGE_TYPE.NORMAL,

                create_time: that.newdata.create_time,

                liked: that.newdata.liked,

                gid: that.newdata.gid,

                extraWidth: 650

              });

            }

          });

        }

      }

    });