store.js
import Vue from 'vue'import Vuex from 'vuex'Vue.use(Vuex)const store = new Vuex.Store({ state: { count: 0 }, mutations: { increment (state) { state.count++ }, decrement (state) { state.count-- } }, actions: { increment (context) { context.commit('increment') }, decrement (context) { context.commit('decrement') } }, getters: { odd:state => state.count }})export default store
组件: