Vue.js 监听属性

demo
 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4   <meta charset="utf-8">
 5   <title>Vue 测试实例</title>
 6   <script src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
 7 </head>
 8 <body>
 9    <div id="watch">
10      分钟：<input type="text"   v-model="minutes">
11      小时：<input type="text" v-model="hours">
12    </div>
13    <p id="show"></p>
14 <script>
15    var vm= new Vue({
16       el:'#watch',
17       data: {
18         minutes: 0,
19         hours: 0
20       },
21       watch:
22       {
23         minutes:function(value) {
24           this.minutes=value;
25           this.hours=value/60;
26         },
27         hours:function(value) {
28           this.minutes=value*60;
29           this.hours=value;
30         }
31       }
32 
33 
34     });
35     vm.$watch('hours', function (newValue, oldValue) {
36       // 这个回调将在 vm.hours 改变后调用
37       document.getElementById ("show").innerHTML = "修改前值为: " + oldValue + "，修改后值为: " + newValue;
38     })
39 </script>
40 </body>
41 </html>
效果：
2018-03-19 23:51:19