官方推薦：

src/vuex/getters.js:

const getters = {
  //這里還可以有第二個(gè)參數(shù)getters览芳，用來(lái)獲取getters里面的其他getters
  friend: (state) => {
    return state.data.friends.filter(x => x._id === state.activeId)[0];
  },
  ......
};

export default getters;

src/vuex/mutations.js:

const mutations = {
  getData: (state, data) => {
    state.data = data;
    ......
  },
};

export default mutations;

src/vuex/actions.js

import axios from 'axios';
const actions = {
  // 這里結(jié)構(gòu)里面不止有commit，也可以有dispatch等鸿竖，這個(gè)也是最常用的沧竟；當(dāng)然也有state、getters
  getAllData: async ({commit}) => {
    let self = {};
    let friends = [];
    await axios.get('../../static/mockdata.json').then(response => {
      self = response.data.self;
      friends = response.data.friend;
      console.log(response.data);
    }, response => {
      console.log("error");
    });
    commit('getData', {
      self, friends
    })
  },
};

export default actions;

src/vuex/store.js:

import Vue from 'vue';
import Vuex from 'vuex';
import mutations from "./mutations";
import getters from "./getters";
import actions from "./actions";

Vue.use(Vuex);

let state = {
    data: { 
         self: {}, 
         friends: [] 
    },
    ......
};

export default new Vuex.Store({
  state,
  mutations,
  actions,
  getters
})

Vuex多模塊寫(xiě)法：

src/store/index.js

import Vue from 'vue'
import Vuex from 'vuex'
import { $fetch } from '../plugins/fetch'
import router from '../router'

import maps from './maps'
import posts from './posts'

Vue.use(Vuex)

const store = new Vuex.Store({
  strict: process.env.NODE_ENV !== 'production',

  state () {
    return {
      user: null,
    }
  },

  getters: {
    user: state => state.user,

    userPicture: (state, getters) => {
      const user = getters.user
      if (user) {
        const photos = user.profile.photos
        if (photos.length !== 0) {
          return photos[0].value
        }
      }
    },
  },

  mutations: {
    user: (state, user) => {
      state.user = user
    },
  },

  actions: {
    async init ({ dispatch }) {
      await dispatch('login')
    },

    async login ({ commit, dispatch }) {
      try {
        const user = await $fetch('user')
        console.log('user', user)
        commit('user', user)

        if (user) {
          // Redirect to the wanted route or home
          router.replace(router.currentRoute.params.wantedRoute || { name: 'home' })

          dispatch('logged-in')
        }
      } catch (e) {
        console.warn(e)
      }
    },

    logout ({ commit, dispatch }) {
      commit('user', null)

      $fetch('logout')

      // If the route is private
      // We go to the login screen
      if (router.currentRoute.matched.some(r => r.meta.private)) {
        router.replace({ name: 'login', params: {
          wantedRoute: router.currentRoute.fullPath,
        }})
      }
    },
  },

  // 引入其他的store
  modules: {
    posts,
  },
})

export default store

src/store/posts.js

import { $fetch } from '../plugins/fetch'

let fetchPostsUid = 0

export default {
  namespaced: true,

  state () {
    return {
      // New post being created
      draft: null,
      // Bounds of the last fetching
      // To prevent refetching
      mapBounds: null,
      // Posts fetched in those map bounds
      posts: [],
      // ID of the selected post
      selectedPostId: null,
      // Fetched details for the selected post
      selectedPostDetails: null,
    }
  },

  getters: {
    draft: state => state.draft,
    posts: state => state.posts,
    // The id field on posts is '_id' (MongoDB style)
    selectedPost: state => state.posts.find(p => p._id === state.selectedPostId),
    selectedPostDetails: state => state.selectedPostDetails,
    // The draft has more priority than the selected post
    currentPost: (state, getters) => state.draft || getters.selectedPost,
  },

  mutations: {
    addPost (state, value) {
      state.posts.push(value)
    },

    addComment (state, { post, comment }) {
      post.comments.push(comment)
    },

    draft (state, value) {
      state.draft = value
    },

    likePost (state, { post, userId }) {
      const index = post.likes.indexOf(userId)
      if (index !== -1) {
        post.likes.splice(index, 1)
      } else {
        post.likes.push(userId)
      }
    },

    posts (state, { posts, mapBounds }) {
      state.posts = posts
      state.mapBounds = mapBounds
    },

    selectedPostId (state, value) {
      state.selectedPostId = value
    },

    selectedPostDetails (state, value) {
      state.selectedPostDetails = value
    },

    updateDraft (state, value) {
      Object.assign(state.draft, value)
    },
  },

  actions: {
    clearDraft ({ commit }) {
      commit('draft', null)
    },

    createDraft ({ commit }) {
      // Default values
      commit('draft', {
        title: '',
        content: '',
        position: null,
        placeId: null,
      })
    },

    async createPost ({ commit, dispatch }, draft) {
      const data = {
        ...draft,
        // We need to get the object form
        position: draft.position.toJSON(),
      }

      // Request
      const result = await $fetch('posts/new', {
        method: 'POST',
        body: JSON.stringify(data),
      })
      dispatch('clearDraft')

      // Update the posts list
      commit('addPost', result)
      dispatch('selectPost', result._id)
    },

    async fetchPosts ({ commit, state }, { mapBounds, force }) {
      let oldBounds = state.mapBounds
      if (force || !oldBounds || !oldBounds.equals(mapBounds)) {
        const requestId = ++fetchPostsUid

        // Request
        const ne = mapBounds.getNorthEast()
        const sw = mapBounds.getSouthWest()
        const query = `posts?ne=${
          encodeURIComponent(ne.toUrlValue())
        }&sw=${
          encodeURIComponent(sw.toUrlValue())
        }`
        const posts = await $fetch(query)

        // We abort if we started another query
        if (requestId === fetchPostsUid) {
          commit('posts', {
            posts,
            mapBounds,
          })
        }
      }
    },

    async likePost ({ commit, rootGetters }, post) {
      const userId = rootGetters.user._id
      commit('likePost', {
        post,
        userId,
      })
      await $fetch(`posts/${post._id}/like`, {
        method: 'POST',
      })
    },

    'logged-in': {
      handler ({ dispatch, state }) {
        if (state.mapBounds) {
          dispatch('fetchPosts', {
            mapBounds: state.mapBounds,
            force: true,
          })
        }
        if (state.selectedPostId) {
          dispatch('selectPost', state.selectedPostId)
        }
      },
      root: true,
    },

    // 這樣寫(xiě)的話dispatch('logout')不僅可以觸發(fā)index.js中的logout缚忧，也可以觸發(fā)這里的logout悟泵，也就是狀       // 態(tài)提升
    logout: {
      handler ({ commit }) {
        commit('posts', {
          posts: [],
          mapBounds: null,
        })
      },
      root: true,
    },

    async selectPost ({ commit, getters }, id) {
      commit('selectedPostDetails', null)
      commit('selectedPostId', id)
      const details = await $fetch(`posts/${id}`)
      commit('selectedPostDetails', details)
    },

    async sendComment({ commit, rootGetters }, { post, comment }) {
      const user = rootGetters.user
      commit('addComment', {
        post,
        comment: {
          ...comment,
          date: new Date(),
          user_id: user._id,
          author: user,
        },
      })

      await $fetch(`posts/${post._id}/comment`, {
        method: 'POST',
        body: JSON.stringify(comment),
      })
    },

    setDraftLocation ({ dispatch, getters }, { position, placeId }) {
      if (!getters.draft) {
        dispatch('createDraft')
      }
      dispatch('updateDraft', {
        position,
        placeId,
      })
    },

    unselectPost ({ commit }) {
      commit('selectedPostId', null)
    },

    updateDraft ({ dispatch, commit, getters }, draft) {
      commit('updateDraft', draft)
    },
  },
}

在 .vue 中使用(推薦)：

<script>
import { createNamespacedHelpers } from 'vuex'

// Vuex mappers
// posts module
const {
  mapGetters: postsGetters,
  mapActions: postsActions,
} = createNamespacedHelpers('posts')

export default {
  computed: {
    ...postsGetters([
      'draft',
      'posts',
      'currentPost',
    ]),

    mapOptions () {
      return {
        fullscreenControl: false,
      }
    },
  },

  methods: {
    ...postsActions([
      'selectPost',
      'setDraftLocation',
    ]),

    onIdle () {
      this.setBounds(this.$refs.map.getBounds())
    },

    onMapClick (event) {
      this.setDraftLocation({
        position: event.latLng,
        placeId: event.placeId,
      })
    },
  },
}
</script>