SOURCE

let Event=new Vue();

Vue.component('person1',{
  template: '<div>我说：<input @keyup="on_change" type="text" v-model="i_said" /></div>',
  methods:{
    on_change:function(){
      Event.$emit('she_said_something',this.i_said);
    }
  },
  data: function(){
    return {
      i_said: ''
    }
  }
})

Vue.component('person2', {
  template: '<div>她说：{{she_said}}</div>',
  data:function(){
    return {
      she_said: ''
    }
  },
  mounted:function(){
    let me=this;
    Event.$on('she_said_something',function(data){
      console.log(data);
      me.she_said=data;
    })
  }
})

new Vue({
  el: '#app'
});

<div id="app">
  <person1></person1>
  <person2></person2>
</div>