vue动态监听浏览器窗口高度

<div ref="page"></div>

data(){
    return{
        clientHeight:'',
    }
}
mouted(){
    this.clientHeight = `${document.documentElement.clientHeight}`;//获取浏览器可视区域高度
    let that = this;
    window.onresize = function(){
       this.clientHeight =  `${document.documentElement.clientHeight}`;
        if(that.$refs.page){
            that.$refs.page.style.minHeight = clientHeight - 100 + 'px';
        }
    }
}
watch:{
    clientHeight(){     //如果clientHeight 发生改变，这个函数就会运行
       this.changeFixed(this.clientHeight) 
    }
}
methods:{
　　changeFixed(clientHeight){
　　　　if(this.$refs.page){
　　　　　　this.$refs.page.style.minHeight = clientHeight -100 + 'px';
　　　　}
　　}
}