vue.js监听

Vue.js 监听属性 watch

<div id = "computed_props"> 千米 : <input type = "text" v-model = "kilometers"> 米 : <input type = "text" v-model = "meters"> </div> <p id="info"></p> <script type = "text/javascript"> var vm = new Vue({ el: '#computed_props', data: { kilometers : 0, meters:0 }, methods: { }, computed :{ }, watch : { kilometers:function(val) { this.kilometers = val; this.meters = val * 1000; }, meters : function (val) { this.kilometers = val/ 1000; this.meters = val; } } }); // $watch 是一个实例方法 vm.$watch('kilometers', function (newValue, oldValue) { // 这个回调将在 vm.kilometers 改变后调用 document.getElementById ("info").innerHTML = "修改前值为: " + oldValue + "，修改后值为: " + newValue; }) </script>