截圖看不清

你的items變量沒有定義，看下你的items是不是有在data里面注冊了？

這個是app.vue的

<template>
??<div?id="app">
????<h1?v-text="title"></h1>
????<input?v-model="newItem"?v-on:keyup.enter="addNew">
??<ul>
????<li?v-for="item?in?items"?v-bind:class="{finished:item.isFinished}"?v-on:click="toggleFinish(item)">
????{{item.label}}
????</li>
??</ul>
??</div>
</template>

<script>
import?Store?from?'./store'

export?default?{
??name:?'app',
??data:function(){
????return?{
??????title:?'this?is?a?todoList',
??????items:Store.fetch(),
??????newItem:'?'
????}
??},
??watch:{
????items:{
??????handler:function(items){
????????Store.save(items)
??????},
??????deep:true
????}
??},
??methods:{
????toggleFinish:function(item){
??????item.isFinished?=?!item.isFinished;
????},
????addNew:function(){
??????this.items.push({
????????label:this.newItem,
????????isFinished:false
??????})
??????this.newItem?=?'';

????}
??}
}
</script>

<style>
#app?{
??font-family:?'Avenir',?Helvetica,?Arial,?sans-serif;
??-webkit-font-smoothing:?antialiased;
??-moz-osx-font-smoothing:?grayscale;
??text-align:?center;
??color:?#2c3e50;
??margin-top:?60px;
}
ul{
??list-style-position:?inside;
}
.finished{
??text-decoration:?underline;
}
</style>

這個是store.js的

const?STORAGE_KEY?=?'todos-vuejs'
export?default{
	fetch(){
		return?JSON.parse(window.localStorage.getItem(STORAGE_KEY)||'[]')
	},
	save?(items){
		window.localStorage.setItem(STORAGE_KEY,JSON.stringify(items))
	}
}