以商家收藏这一功能为例：
1. 首先App.vue中根据url 设置好 商家的id

<script>
import {urlParse} from './common/js/util.js'
import Header from './components/header/Header.vue'

const err_OK = 0;

export default{
  data(){
    return { /* 商家默认有id */
      seller:{
        id:(()=>{
         /* 从地址栏中的url中通过urlParam函数解析，得到id */
          let queryParam = urlParse();
          console.log(queryParam);
          return queryParam.id;
        })()
      }
    }
  },
  created(){
    this.$http.get('./api/seller?id='+this.seller.id).then((res)=>{
      var resData  = res.data;
      if(resData.errno  === err_OK){
        /* this.seller =  resData.data; 会覆盖掉id */
        /* 防止把id覆盖掉，使用es6的一个语法:扩展了对象的属性，在原来的基础上添加response.data的值，不会覆盖掉原来的id属性 */
        this.seller = Object.assign({},this.seller,resData.data);
        console.log(this.seller.id);
      }
    },(res)=>{
      alert(res.status);
    });
  },
  components: {
    'v-header': Header
  }
}
</script>

2、seller.vue： 设置和读取localstorage

<div class="favorite" @click="toggleFavorite($event)">
    <span class="icon icon-favorite" :class="{'active':favorite}"></span>
    <div class="text">{{favoriteText}}</div>
</div>

----
import {saveToLocal,loadFromLocal} from '../../common/js/store.js'
export default{
    props:{
        seller: {
            type: Object
        }
    },
    data(){
        return{
            favorite: (()=>{
                return loadFromLocal(this.seller.id,'favorite',false);
            })()
        }
    },
    computed:{
        favoriteText(){
            return this.favorite? '已收藏': '收藏';
        }
    },

    methods:{
        toggleFavorite(event){
            if(!event._constructed){
                return;
            }
            this.favorite = !this.favorite;
            saveToLocal(this.seller.id, 'favorite', this.favorite);
        }
    }
}

3、保存的读取localStorage的接口—-store.js：

/**
 * [保存数据到localstorage]
 * @param  {[Number]} id  [商家id]
 * @param  {[type]} key [属性值]
 * @param  {[type]} value [value值]
 * @return {[type]}       [description]
 */
export function saveToLocal(id, key, value) {
    let seller = window.localStorage.__seller__;
    if (!seller) {
        seller = {};
        seller[id] = {};

    } else {
        seller = JSON.parse(seller);
        if (!seller[id]) {
            seller[id] = {};
        }
    }
    seller[id][key] = value;
    window.localStorage.__seller__ = JSON.stringify(seller);
};
/**
 * [从localstorage读取数据]
 * @param  {[Number]} id  [商家id]
 * @param  {[type]} key [属性值]
 * @param  {[type]} def [属性值的默认取值，当没有保存key时，返回默认值]
 * @return {[type]}     [属性值对应的value值]
 */
export function loadFromLocal(id, key, def) {
    let seller = window.localStorage.__seller__;
    if(!seller){
        return def;
    }

    seller = JSON.parse(seller);
    if(!seller[id]){
        return def;
    }

    let ret = seller[id][key];
    return ret || def;
}

4.util.js：

/**
 * [解析url参数]
 * @example ?id=12345&a=1
 * @return Object {id:12345,a:1}
 */
export function urlParse(){
    let url = decodeURIComponent(window.location.search);
    let obj = {};
    let reg = /[?&][^?&]+=[^?&]+/g;
    //['?id=12345','a=1']
    let arr = url.match(reg);
    if(arr){
        arr.forEach((item)=>{
            let  tempArr =  item.substring(1).split('=');
            let key = decodeURIComponent(tempArr[0]);
            let value = decodeURIComponent(tempArr[1]);
            obj[key] = value;
        })
    }
    return obj;
}