//用于监听本地缓存
export default function dispatchEventStroage () {
    const signSetItem = localStorage.setItem
    localStorage.setItem = function (key, val) {
      let setEvent = new Event('setItemEvent')
      setEvent.key = key
      setEvent.newValue = val
      window.dispatchEvent(setEvent)
      signSetItem.apply(this, arguments)
    }
  }