<template>
 <div class="hello">
  <input type="text">
  <button>增加事项</button>
  <ul>
   <li>item</li>
  </ul>
 </div>
</template>

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

const store = new Vuex.Store({
 state: {
  inputVal: 'lily',
  list: ['1', '2', '3']
 },
 mutations: {
  changeListValue(state, inputVal) {
   state.list.push(inputVal)
   state.inputVal = ''
  },
  handleDel(state, idx) {
   state.list.splice(idx, 1)
  }
 },
 actions: {
  changeListValue: ({commit}, inputVal) => {
   return commit('changeListValue', inputVal)
  },
  handleDel: ({commit}, idx) => {
   return commit('handleDel', idx)
  }
 }
})
export default store

<template>
 <div class="hello">
  <input v-model="$store.state.inputVal" type="text">
  <button @click="changeListValue(inputVal)">增加事项</button>
  <ul v-for="(item, idx) in list">
   <li @click="handleDel(idx)">{{item}}</li>
  </ul>
 </div>
</template>

<script>
 import {mapState, mapActions} from 'vuex'
 export default {
  name: 'HelloWorld',
  computed: {
   ...mapState(['list', 'inputVal'])
  },
  methods: {
   ...mapActions(['changeListValue', 'handleDel'])
  }
 }
</script>