在app.vue的页面中添加以下代码

let beginTime = 0; //开始时间
    let differTime = 0; //时间差
    window.onunload = function() {
      differTime = new Date().getTime() - beginTime;
      if (differTime <= 5) {
        debugger
        localStorage.clear();
        Cookies.remove('token');
      }
    };
    //此方法刷新页面时也会执行
    window.addEventListener('beforeunload',()=>{
        beginTime = new Date().getTime();
    });