SOURCE

var app=new Vue({
	el:'#app',
  created:function(){
  	var that=this;
  	this.$on('test',function(val){
    	console.log(val)
    	that.testValue=val.age;  
    })
  },
  data:{
  	age:20,
  	testValue:''
  },
  methods:{
  	test:function(){
    	this.age++;
    	this.$emit('test',{age:this.age})
    }
  }
})

<div id="app">
<p>年龄: {{testValue}}</p>
<button @click='test'>test</button>
</div>