<script>
   let UnloadFn = null;
   export default {
   mounted() {
      window.addEventListener('beforeunload', (UnloadFn (e)=>this.beforeunloadHandler(e)));
          },
   methods:{
     beforeunloadHandler(e) {
      console.log('浏览器刷新了')
      //写需要执行的逻辑
     },
   },
//关闭监听事件
 destroyed(){
    console.log('beforeDestroy')
    
    window.removeEventListener('beforeunload', UnloadFn, false)
  },
}