1.子传父

用$emit（“事件”，参数）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
   <div id='app'>
       <my-father></my-father>
   </div>
    <script src='js/vue.js'></script>
    <script>
       Vue.component("my-father",{
           template:`
              <div>
                  <my-child @send='revMsg'></my-child>
                  <a href="#">{{mess}}</a>
             </div>
            `,
           data:function(){
               return{
                   mess:''
               }
           },
           methods:{
               revMsg:function(txt){
                   this.mess=txt
               }
           }
       }) 
       
       Vue.component("my-child",{
           template:`
              <button @click='sendMsg'>按钮</button>
           `,
           data:function(){
               return{
                   msg:'我是子组件中的数据，要传给父组件'
               }
           },
           methods:{
               sendMsg:function(){
//                   this.$emit('事件',参数)
                     this.$emit('send',this.msg)
               }
           }
           
       })
        
       new Vue({
           el:'#app'
       })
    
    </script>
</body>
</html>

2.父传子

用props 属性来传值

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
  <div id='app'>
      <my-father></my-father>
  </div>
   <script src='js/vue.js'></script> 
   <script>
       Vue.component('my-father',{
           template:`
                <div>
                     <my-tit v-bind:tit='title'></my-tit>
                     <my-fruit v-bind:fruList='list'></my-fruit>
                </div>
           `,
           data:function(){
               return{
                   list:['apple','pear','banana'],
                   title:'水果列表'
               }
           }
       })
       
       Vue.component('my-tit',{
           props:['tit'],
           template:`
                 <h2>{{tit}}</h2>
               `
       })
       
       
       Vue.component('my-fruit',{
           props:['fruList'],
           template:`
                <ul>
                    <li v-for="value in fruList">{{value}}</li>
                </ul>
             `
       })
       
       
       new Vue({
           el:'#app'
       })
    
    </script>
</body>
</html>

3.非父子之间传值

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
   <div id='app'>
       <child></child>
       <son></son>
   </div>
    <script src='js/vue.js'></script>
    <script>
      var bus=new Vue();  
        
      Vue.component('child',{//a
          template:`
             <div>
                <h2>我是child组件</h2>
                <button @click='sendMsg'>发送数据</button>
             </div>
         `,
          data:function(){
              return{
                  msg:'我是child组件中的数据，要传给son组件'
              }
          },
          methods:{
              sendMsg:function(){//发送数据
                 bus.$emit('send',this.msg)  
              }
          }
      })
      
      Vue.component('son',{//b
          template:`
           <div>
                <h2>我是son组件</h2>
                <a>{{mess}}</a>
           </div>
         `,
          data:function(){
             return{
                 mess:''
             }
          },
          mounted:function(){
            bus.$on('send',msg=>{
                console.log(this);
                this.mess=msg
            })  
              
          }
          
          
      })
        
        
      new Vue({
          el:'#app'
      })
    </script>
</body>
</html>