官网：Vuex 是什么？ | Vuex (vuejs.org)
https://v3.vuex.vuejs.org/zh/
创建一个vue2的新项目名为vuex-demo，安装命令 npm install vuex@3
新建index.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++}}})export default store修改main.js，注入
import Vue from 'vue'
import App from './App.vue'
import store from './store'Vue.config.productionTip = falsenew Vue({render: h => h(App),store: store
}).$mount('#app')
HelloWorld.vue修改
<template><div class="hello">{{ this.$store.state.count }}<button @click="add">+1</button></div>
</template><script>
export default {name: 'HelloWorld',methods: {add() {this.$store.commit('increment') // commit mutation }}
}
</script><style scoped> </style>App.vue修改
<template><div id="app"><HelloWorld/></div>
</template><script>
import HelloWorld from './components/HelloWorld.vue'export default {name: 'App',components: {HelloWorld}
}
</script><style>
#app {font-family: Avenir, Helvetica, Arial, sans-serif;-webkit-font-smoothing: antialiased;-moz-osx-font-smoothing: grayscale;text-align: center;color: #2c3e50;margin-top: 60px;
}
</style>
运行
修改HelloWorld.vue
<template><div class="hello"><!-- {{ this.$store.state.count }} -->{{ count }}<button @click="add">+1</button></div>
</template><script>
export default {name: 'HelloWorld',computed: {count() {return this.$store.state.count // access state}},methods: {add() {this.$store.commit('increment') // commit mutation }}
}
</script><style scoped> </style>
刷新，效果不变
修改HelloWorld.vue，效果还是不变
<template><div class="hello"><!-- {{ this.$store.state.count }} -->{{ count }}<button @click="add">+1</button></div>
</template><script>import { mapState } from 'vuex';export default {name: 'HelloWorld',computed:mapState(['count']),// computed: {// count() {// return this.$store.state.count // access state// }// },methods: {add() {this.$store.commit('increment') // commit mutation }}
}
</script><style scoped> </style>
修改index.js
import Vue from 'vue'
import Vuex from 'vuex'Vue.use(Vuex)const store = new Vuex.Store({state: {count: 0,todos: [{ id: 1, text: '吃饭', done: true },{ id: 2, text: '睡觉', done: false }]},mutations: {increment (state) {state.count++}}})export default store修改HelloWorld.vue
<template><div class="hello"><!-- {{ this.$store.state.count }} -->{{ count }}<button @click="add">+1</button><ul><li v-for="todo in todos" :key="todo.id">{{ todo.text }}</li></ul></div>
</template><script>import { mapState } from 'vuex';export default {name: 'HelloWorld',computed:mapState(['count','todos']),methods: {add() {this.$store.commit('increment') // commit mutation }}
}
</script><style scoped> </style>
修改
修改index.js
import Vue from 'vue'
import Vuex from 'vuex'Vue.use(Vuex)const store = new Vuex.Store({state: {count: 0,todos: [{ id: 1, text: '吃饭', done: true },{ id: 2, text: '睡觉', done: false }]},mutations: {increment (state) {state.count++}}, getters: {doneTodos: state => {return state.todos.filter(todo => todo.done)}}})export default store修改HelloWorld.vue
<template><div class="hello"><!-- {{ this.$store.state.count }} -->{{ count }}<button @click="add">+1</button><ul><li v-for="todo in doneTodos" :key="todo.id">{{ todo.text }}</li></ul></div>
</template><script>import { mapState,mapGetters} from 'vuex';export default {name: 'HelloWorld',computed:{
...mapState(['count','todos']),
...mapGetters(['doneTodos'])methods: {add() {this.$store.commit('increment') // commit mutation }}
}
</script><style scoped> </style>
刷新
修改index.js，每次加2
import Vue from 'vue'
import Vuex from 'vuex'Vue.use(Vuex)const store = new Vuex.Store({state: {count: 0,todos: [{ id: 1, text: '吃饭', done: true },{ id: 2, text: '睡觉', done: false }]},mutations: {increment (state,n) {state.count += n}}, getters: {doneTodos: state => {return state.todos.filter(todo => todo.done)}}})export default store修改HelloWorld.vue
<template><div class="hello"><!-- {{ this.$store.state.count }} -->{{ count }}<button @click="add">+1</button><ul><li v-for="todo in doneTodos" :key="todo.id">{{ todo.text }}</li></ul></div>
</template><script>import { mapState,mapGetters} from 'vuex';export default {name: 'HelloWorld',// computed:mapState(['count','todos']),computed:{
...mapState(['count','todos']),
...mapGetters(['doneTodos'])},// computed: {// count() {// return this.$store.state.count // access state// }// },methods: {add() {this.$store.commit('increment',2) // commit mutation }}
}
</script><style scoped> </style>
刷新，每次加2
