// book.js
export default {
    state: {
        fileName: 'Biomedicine|2014_Book_Self-ReportedPopulationHealthA',
        toggle: 0
    },
    mutations: {
        'CHANGEFILENAME': (state, fileName) => {
            state.fileName = fileName
        },
        'CHANGETOGGLE': (state, toggle) => {
            state.toggle = toggle
        }
    },
    actions: {
        changeFileName: ({commit}, fileName) => commit('CHANGEFILENAME', fileName),
        changeToggle: ({commit}, toggle) => commit('CHANGETOGGLE', toggle)
    }
}

//getters.js
export default {
    fileName: state => state.book.fileName,
    toggle: state => state.book.toggle
}

//index.js
import Vue from 'vue'
import Vuex from 'vuex'
import book from './modules/book'
import getters from './getters'

Vue.use(Vuex)

export default new Vuex.Store({
    modules: {
        book
    },
    getters
})

然后我在computed里面使用…mapGetters([‘toggle’])混入，调用方法使用了this.$store.commit(‘changeToggle’, 0),结果就报错了，但是我百度了下，发现只要不使用混入采用如下写法就没有问题，这是为什么?

toggle: {
	get: function () {
		return this.$store.state.book.toggle
	},
	set: function (toggle) {
		this.$store.state.book.toggle = toggle
	}
},