Vuex学习总结 - State（3）

4.Vuex核心概念

4.1 State

使用mapState。

import {mapState} from 'vuex'

export default {
	name: "Counter",
	// computed: {
	//     count() {
	//         return this.$store.state.count
	//     }
	// },
	computed: mapState({
		count: state => state.count
	}),
	methods: {
		increment() {
			this.$store.commit('increment')
		}
	}
}

<template>
    <div>
        <button @click="increment">加一</button> {{count2}}
        <br/>
        {{countAlias1}}
    </div>
</template>

<script>
    import {mapState} from 'vuex'

    export default {
        name: "Counter",
        // computed: {
        //     count() {
        //         return this.$store.state.count
        //     }
        // },
        computed: mapState({
            count2: state => state.count,
            countAlias1: 'count2'
        }),
        methods: {
            increment() {
                this.$store.commit('increment')
            }
        }
    }
</script>

<template>
    <div>
        <button @click="increment">加一</button> {{count}}
        <br/>
        {{countAlias}}
        <br/>
        {{countPlusLocalState}}
    </div>
</template>

<script>
    import {mapState} from 'vuex'

    export default {
        name: "Counter",
        data() {
            return {
                localCount: 2
            }
        },
        computed: mapState({
            count: state => state.count,
            countAlias: 'count',
            countPlusLocalState(state) {
                return state.count + this.localCount
            },
        }),
        methods: {
            increment() {
                this.$store.commit('increment')
            }
        }
    }
</script>

将本地计算属性与mapState合并的方法。

<template>
    <div>
        <button @click="increment">加一</button> {{count}}
        <br/>
        {{localComputed}}
    </div>
</template>

<script>
    import {mapState} from 'vuex'

    export default {
        name: "Counter",
        data() {
            return {
                localCount: 2
            }
        },
        computed: {
            localComputed () {
                return this.count + this.localCount
            },
            ...mapState(['count']),
        },
        methods: {
            increment() {
                this.$store.commit('increment')
            }
        }
    }
</script>

Vuex实例中的共享状态可以被追踪和调试，如果一个状态属于单个组件，那么将其保留为本地状态就可以了。