vue 实时监听键盘触发事件

mounted() {
      this.$nextTick(() => {
        this.keyDown();
      });
},
methods: {
     keyDown() {
        let that = this;
        document.onkeydown =  (e) => {
          //事件对象兼容
          let e1 = e || event || window.event || arguments.callee.caller.arguments[0]
          if(e1 && e1.keyCode == 46) {//del键，其他按键对应数值，打印查看即可
             
          }
        }
      }
}