<div id="vue-todolist" class="todolistDiv">
  <span> todolist</span>
  <input class="ipt" type="text" v-model="inputVaule" />
</div>

var vm=new Vue({
 el: '#vue-todolist',
 data: { 
  inputVaule:""
 }
})

<div id="vue-todolist" class="todolistDiv">
  <span> todolist</span>
    <input class="ipt" type="text" v-model="inputVaule" v-on:keyup.enter="add"/>
    <button v-on:click="add" class="btn">add</button>
    <ul >
      <li v-for="item in items" >
      <div class="liDiv">       
        <label>{{item.text}}</label>      
      </div>
      </li>
    </ul>
  </div>

var vm=new Vue({
 el: '#vue-todolist',
 data: { 
  items:[{text:'1'},{text:'2'}]
  inputVaule:""
 },
 methods:{
   add:function(){
    this.items.push({text:this.inputVaule});
    this.inputVaule="";
  }
 }
})

<li v-for="item in items" >
      <div class="liDiv">
        <input type="checkbox" v-model="item.completed">
        <label v-bind:class="{ complete:item.completed }">{{item.text}}</label>
        <button v-on:click="removeTodo(item)" class="btn">x</button>
      </div>
</li>

var vm=new Vue({
 el: '#vue-todolist',
 data: { 
  items:[{text:'1',completed:true},{text:'2',completed:false}]
  inputVaule:""
 },
 methods:{
   add:function(){
    this.items.push({text:this.inputVaule});
    this.inputVaule="";
  },
  removeTodo: function (todo) {
   this.items.splice(this.items.indexOf(todo), 1)
  }
 }
})

var STORAGE_KEY = 'todos-vuejs'//名称
var todoStorage = { 
 save: function (todos) {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(todos))
 }
} 

watch:{
  items:{
    handler:function(items){
      todoStorage.save(items)
    },
    deep:true//一定要加
  }
 }

var STORAGE_KEY = 'todos-vuejs'//名称
var todoStorage = {
 fetch: function () {
  var todos = JSON.parse(localStorage.getItem(STORAGE_KEY) || '[]')
  todos.forEach(function (todo, index) {
   todo.id = index
  })
  todoStorage.uid = todos.length
  return todos
 },
 save: function (todos) {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(todos))
 }
} 

data: {
  items:todoStorage.fetch(),//直接从localstroage拿数据
  inputVaule:""
 },