vue监听浏览器窗口的变化，随着窗口变化调整里面table的宽高

1.在data中设置：

1  tableHeight:"500",
2  screenHeight:window.innerHeight,

2.在mounted中设置：

1   mounted() {
2       const that = this
3       window.onresize =()  =>{
4         return (()=>{
5           window.screenHeight = window.innerHeight
6           this.screenHeight = window.screenHeight;
7         })()
8       }
9     },

3.在watch中监听：

1   watch:{
2       screenHeight(val){
3         this.screenHeight = val
4         this.tableHeight = this.screenHeight - 250
5       }
6     },