vue3中使用vuex
1、注入store
使用Vue3、Vuex4版本，通过如下方式向注入store，
import { createApp } from 'vue';
import App from './App.vue';
import {createStore} from 'vuex';
const store = createStore({
state: {
counter: 0
},
getters: {
counter10times(state) {
return state.counter * 10;
}
},
mutations: {
increaseCounter(state) {
state.counter++;
}
},
modules: {
a: {
namespaced: true,
state: {aName: 'A·a'},
getters: {
aFirstName(state) {
return state.aName.split('·')[0];
}
},
mutations: {
changeAName(state) {
state.aName = 'A-a';
}
},
actions: {
callChangeCNameAsync({dispatch}) {
// 触发子模块的action，相对与自身的路径
setTimeout(() => {
dispatch('c/changeCNameAsync');
}, 500);
}
},
modules: {
c: {
namespaced: true,
state: {cName: 'C·c'},
getters: {
cFirstName(state) {
return state.cName.split('·')[0];
}
},
mutations: {
changeCName(state, payload) {
state.cName = `C-c-${payload.suffix}`;
}
},
actions: {
changeCNameAsync({commit, rootState}) {
setTimeout(() => {
// 提交其他模块的mutation，mutation是全局的
commit('increaseCounter', null, {root: true});
// 提交局部模块的mutation，不需要加前缀
commit('changeCName', {
suffix: rootState.counter
});
}, 500);
}
}
}
}
},
b: {
namespaced: true,
state: {bName: 'B·b'},
getters: {
bNewName(state, getters, rootState, rootGetters) {
// 局部state
const bName = state.bName.split('·')[0];
// 其他模块的getter
const cFirstName = rootGetters['a/c/cFirstName'];
// 其他模块的state
const aName = rootState.a.aName;
return `${bName} ${cFirstName} ${aName}`;
}
},
mutations: {
changeBName(state) {
state.bName = 'B-b';
}
}
}
}
});
createApp(App).use(store).mount('#app');
- 将刚才的加了命名空间的store注入到Vue组件树中。这样在所有的Vue组件中，都能够通过this.$store方式访问store。
- Vue组件通过computed属性来监听store的数据变化。
看下面的示例，computed依赖了this.$store里面的一些模块的state和getters，并将计算结果展示在界面上。
<template>
<div>
{{counter}}
{{bName}}
{{cFirstName}}
</div>
</template>
<script>
export default {
computed: {
counter() {
return this.$store.state.counter;
},
bName() {
return this.$store.state.b.bName;
},
cFirstName() {
return this.$store.getters['a/c/cFirstName'];
}
}
}
</script>
<style>
#app {
margin-top: 60px;
}
</style>
下面看下Vue组件中改变状态的示例，
可以看到Vue组件中通过methods方法调用this.$store的commit和dispatch方法来提交修改和触发action。
/**
* @file main.js
*/
import { createApp } from 'vue';
import App from './App.vue';
import {createStore} from 'vuex';
const store = createStore({
state: {
counter: 0
},
getters: {
counter10times(state) {
return state.counter * 10;
}
},
mutations: {
increaseCounter(state) {
state.counter++;
}
},
modules: {
a: {
namespaced: true,
state: {aName: 'A·a'},
getters: {
aFirstName(state) {
return state.aName.split('·')[0];
}
},
mutations: {
changeAName(state) {
state.aName = 'A-a';
}
},
actions: {
callChangeCNameAsync({dispatch}) {
// 触发子模块的action，相对于自身的路径
setTimeout(() => {
dispatch('c/changeCNameAsync');
}, 500);
}
},
modules: {
c: {
namespaced: true,
state: {cName: 'C·c'},
getters: {
cFirstName(state) {
return state.cName.split('·')[0];
}
},
mutations: {
changeCName(state, payload) {
state.cName = `C-c-${payload.suffix}`;
}
},
actions: {
changeCNameAsync({commit, rootState}) {
setTimeout(() => {
// 提交其他模块的mutation，mutation是全局的
commit('increaseCounter', null, {root: true});
// 提交局部模块的mutation，不需要加前缀
commit('changeCName', {
suffix: rootState.counter
});
}, 500);
}
}
}
}
},
b: {
namespaced: true,
state: {bName: 'B·b'},
getters: {
bNewName(state, getters, rootState, rootGetters) {
// 局部state
const bName = state.bName.split('·')[0];
// 其他模块的getter
const cFirstName = rootGetters['a/c/cFirstName'];
// 其他模块的state
const aName = rootState.a.aName;
return `${bName} ${cFirstName} ${aName}`;
}
},
mutations: {
changeBName(state) {
state.bName = 'B-b';
}
}
}
}
});
createApp(App).use(store).mount('#app');
/**
* @file App.vue
*/
<template>
<div>
{{counter}}
{{bName}}
{{cFirstName}}
<button @click="modifyBName">修改b的name</button>
<button @click="modifyCName">修改c的name</button>
</div>
</template>
<script>
export default {
computed: {
counter() {
return this.$store.state.counter;
},
bName() {
return this.$store.state.b.bName;
},
cFirstName() {
return this.$store.getters['a/c/cFirstName'];
}
},
methods: {
modifyBName() {
this.$store.commit('b/changeBName');
},
modifyCName() {
this.$store.dispatch('a/callChangeCNameAsync');
}
}
}
</script>
<style>
#app {
margin-top: 60px;
}
</style>
2、辅助函数
我们知道我们使用Vuex时候，通过computed绑定store的state和getters的数据，通过methods中调用this.$store的commit和dispatch方法来改变状态。
但是每次都要写this.$store，当需要绑定的数据多的时候会比较繁杂，因此Vuex提供了辅助函数来简化代码。辅助函数包括
<template>
<div>
{{counter}}
{{bName}}
{{counter10times}}
{{cFirstName}}
<button @click="modifyBName">修改b的name</button>
<button @click="modifyCName">修改c的name</button>
</div>
</template>
<script>
import {mapState, mapGetters, mapMutations, mapActions} from 'vuex'
export default {
computed: {
...mapState({
// 将this.$store.state.counter映射为counter
counter: state => state.counter,
// 也可以这样实现
// counter: 'counter',
bName: state => state.b.bName
}),
// 全局的getters
...mapGetters(['counter10times']),
// 也可以这样实现，指定组件中的数据名称
// ...mapGetters({
// counter10times: 'counter10times'
// }),
// 子模块的getters
...mapGetters({
cFirstName: 'a/c/cFirstName'
}),
// 带有命名空间的子模块也可以这样实现映射，在方法多的时候可以简化代码
// ...mapGetters('a/c', [
// 'cFirstName'
// ])
},
methods: {
// 映射mutations到方法
...mapMutations({
modifyBName: 'b/changeBName'
}),
// 也可以这样实现
// ...mapMutations('b', {
// modifyBName: 'changeBName'
// }),
// 带有命名空间的子模块映射到组件的方法
...mapActions('a', {
modifyCName: 'callChangeCNameAsync'
}),
}
}
</script>
<style>
#app {
margin-top: 60px;
}
</style>
3、 组件之间共享数据
<template>
<div>
{{counter}}
{{counter10times}}
<b-child></b-child>
<c-child></c-child>
<button @click="modifyBName">修改b的name</button>
<button @click="modifyCName">修改c的name</button>
</div>
</template>
<script>
import {mapState, mapGetters, mapMutations, mapActions} from 'vuex'
import bChild from './components/bChild';
import cChild from './components/cChild';
export default {
computed: {
...mapState({
counter: state => state.counter,
// 也可以这样实现
// counter: 'counter',
}),
// 全局的getters
...mapGetters(['counter10times']),
// 也可以这样实现，指定组件中的数据名称
// ...mapGetters({
// counter10times: 'counter10times'
// }),
},
components: {
'b-child': bChild,
'c-child': cChild
},
methods: {
// 映射mutations到方法
...mapMutations({
modifyBName: 'b/changeBName'
}),
// 也可以这样实现
// ...mapMutations('b', {
// modifyBName: 'changeBName'
// }),
// 带有命名空间的子模块映射到组件的方法
...mapActions('a', {
modifyCName: 'callChangeCNameAsync'
}),
}
}
</script>
<style>
#app {
margin-top: 60px;
}
</style>
转载于 https://www.jianshu.com/p/54608e9f93f2