全局调用vuex的写法及使用-----------下拉框数据的存储+使用

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相同点：mutations和action都是用来改变Vuex store的状态的；

不同点：mutations提供的回调函数是同步的；

而actions提供的方法是异步的，此外，actions的方法最终还是通过调用mutations的方法来实现修改vuex的状态的。

dispatch：含有异步操作，例如向后台提交数据，写法： this.$store.dispatch('actions方法名',值)

commit：同步操作，写法：this.$store.commit('mutations方法名',值)

下拉框数据

1.user.js

主要看state里的userData

mutations里的SET_USERDATA

actions里的login、allLogin

// import { login, logout, getInfo } from '@/api/user'
import api from '@/api/index'
import { getToken, setToken, removeToken } from '@/utils/auth'
import router, { resetRouter } from '@/router'

const state = {
  token: getToken(),
  name: '',
  avatar: '',
  introduction: '',
  roles: [],
  userData: sessionStorage.getItem('userData') != null ? JSON.parse(sessionStorage.getItem('userData')) : {}
}

const mutations = {
  SET_TOKEN: (state, token) => {
    state.token = token
  },
  SET_INTRODUCTION: (state, introduction) => {
    state.introduction = introduction
  },
  SET_NAME: (state, name) => {
    state.name = name
  },
  SET_AVATAR: (state, avatar) => {
    state.avatar = avatar
  },
  SET_ROLES: (state, roles) => {
    state.roles = roles
  },
  SET_USERDATA: (state, data) => {
    state.userData = data
    sessionStorage.setItem('userData', JSON.stringify(data))
  }
}

const actions = {
  // user login
  login({ commit }, userInfo) {
    const { userName } = userInfo
    return new Promise((resolve, reject) => {
      api.newlogin({ uid: userName.trim() }).then(response => {
        const { data } = response
        commit('SET_TOKEN', data.token)
        commit('SET_USERDATA', data)
        // console.log(data.token, '2222')
        setToken(data.token)
        resolve()
      }).catch(error => {
        reject(error)
      })
    })
  },
  allLogin({ commit }, userInfo) {
    return new Promise((resolve, reject) => {
      api.byToken({ token: userInfo }).then(response => {
        const { data } = response
        commit('SET_USERDATA', data)
        resolve()
      }).catch(error => {
        reject(error)
      })
    })
  },
  // get user info
  getInfo({ commit, state }) {
    return new Promise((resolve, reject) => {
      // api.newgetInfo(state.token).then(response => {
      //   const { data } = response
      //   if (!data) {
      //     reject('Verification failed, please Login again.')
      //   }

      //   const { roles, name, avatar, introduction } = data

      //   // roles must be a non-empty array
      //   if (!roles || roles.length <= 0) {
      //     reject('getInfo: roles must be a non-null array!')
      //   }
      var data = {
        roles: ['admin']
      }
      commit('SET_ROLES', ['admin'])
      commit('SET_NAME', 'admin')
      //   commit('SET_AVATAR', avatar)
      //   commit('SET_INTRODUCTION', introduction)
      resolve(data)
      // }).catch(error => {
      //   reject(error)
      // })
    })
  },

  // user logout
  logout({ commit, state }) {
    return new Promise((resolve, reject) => {
      commit('SET_TOKEN', '')
      commit('SET_ROLES', [])
      removeToken()
      resetRouter()
      resolve()
      // logout(state.token).then(() => {
      //   commit('SET_TOKEN', '')
      //   commit('SET_ROLES', [])
      //   removeToken()
      //   resetRouter()
      //   resolve()
      // }).catch(error => {
      //   reject(error)
      // })
    })
  },

  // remove token
  resetToken({ commit }) {
    return new Promise(resolve => {
      commit('SET_TOKEN', '')
      commit('SET_ROLES', [])
      removeToken()
      resolve()
    })
  },

  // dynamically modify permissions
  changeRoles({ commit, dispatch }, role) {
    return new Promise(async resolve => {
      const token = role + '-token'

      commit('SET_TOKEN', token)
      setToken(token)

      const { roles } = await dispatch('getInfo')

      resetRouter()

      // generate accessible routes map based on roles
      const accessRoutes = await dispatch('permission/generateRoutes', roles, { root: true })

      // dynamically add accessible routes
      router.addRoutes(accessRoutes)

      // reset visited views and cached views
      dispatch('tagsView/delAllViews', null, { root: true })

      resolve()
    })
  }
}

export default {
  namespaced: true,
  state,
  mutations,
  actions
}

2.将user.js写入getters.js中

const getters = {
  token: state => state.user.token,
  avatar: state => state.user.avatar,
  name: state => state.user.name,
  introduction: state => state.user.introduction,
  roles: state => state.user.roles,
}

3.触发这个vuex生成数据（dispatch触发actions里的方法）

dispatch：含有异步操作，例如向后台提交数据，写法： this.$store.dispatch('actions方法名',值)

commit：同步操作，写法：this.$store.commit('mutations方法名',值)

// 1.不需要传参的触发
this.$store.dispatch('user/logout') 
// 2.触发时需要传参
this.$store.dispatch('user/changeRoles', val).then(() => {...})
this.$store.dispatch('user/allLogin', Cookies.get('token')) // 接口传参token获取登录信息 并存到vuex里userData
this.$store.dispatch('user/login', this.loginForm).then(() => { // 登录接口的触发存储，this.loginForm（账号、密码...）
            // this.selectInfo()
            this.loading = false
            this.$router.push({
              path: this.redirect || '/',
              query: this.otherQuery
            })
          })
            .catch(res => {
              this.$tips({
                content: res,
                type: 'error'
              })
              this.loading = false
            })
            

4.使用vuex数据

this.$store.getters.name  // 写入了getters.js文件里 需这样使用
this.$store.state.user.userData.employeeName // userData未写入getters.js文件里 所以得这样使用