vue操作select获取option值

<div id="app">
       <select  class="fl" v-model="ProductActive"  @change="changeProduct($event)" >
            <option v-for="(item,index) in productList" :key="index" :value='item.id'>{{item.title}}</option>  
       </select>  
  </div>

data:{
        productList:[{id:1,title:"北京"},{id:2,title:"上海"},{id:3,title:"广州"},{id:4,title:"四川"}],
        ProductActive:"1",//获取被选中的value值 默认选中的是1(北京)
     },
  methods: {
           changeProduct(event) {
             this.ProductActive = event.target.value; //获取option对应的value值
             console.log("你选中了",this.ProductActive)
           },
       }