<!DOCTYPE html><html><head><meta charset="UTF-8"><title>VUE监听属性</title><script src="js/vue.min.js"></script></head><body><div id="app"><p style="font-size: 25px;">自增器</p><button @click="counter++" style="font-size: 25px;">点我</button></div><script>var vm=new Vue({el:'#app',data:{counter:1}})vm.$watch('counter',function(nval,oval){console.log('自增器值的变化:'+oval+'变为:'+nval+'|')})</script></body></html>
则每次单击按钮的时候,console的输出值会自增。
<!DOCTYPE html><html><head><meta charset="UTF-8"><title>VUE监听案例2</title><script src="js/vue.min.js"></script></head><body><div id="computed_props">千米:<input type="text" v-model="kilometers" />米:<input type="text" v-model="meters" /></div><script>var vm=new Vue({el:'#computed_props',data:{kilometers:0,meters:0},methods:{},watch:{kilometers:function(val){this.kilometers=val;this.meters=val*1000;},meters:function(val){this.kilometers=val/1000;this.meters=val;}}})//$watch是一个实例方法;vm.$watch('kilometers',function(newValue,oldValue){document.getElementById('info').innerHTML='修改前值为:'+oldvalue+",修改后值为:"+newvalue;})</script></body></html>
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