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网络编程 发布日期:2025/1/11 浏览次数:1
1. 实践环境
Vue 2.9.6
2. 问题描述
<script> import { mapState } from 'vuex'; export default { name: "displayCount", computed: { ...mapState({ ...略 count: state => state.a.count }) }, methods: { increaseCount () { this.count = this.count + 1 } } }; </script> <style> </style>
如上,我们希望在执行increaseCount函数时,给mapstate函数中映射定义的this.count赋值,给该值增加1,结果,提示
[Vue warn]: Computed property "count" was assigned to but it has no setter.
3. 解决方案1
如下,把属性“移出mapState”,然后为属性新增get,set方法,分别用于获取值和改变值(按store状态管理规定的方式)
<script> import { mapState } from 'vuex'; export default { name: "displayCount", computed: { ...mapState({ ...略 }), count: { get() { return this.$store.state.a.count; }, set(val) { this.$store.commit("increaseCount", val); } } }, methods: { increaseCount () { this.count = this.count + 1 } } }; </script>
注意:this.$store.commit("increaseCount", val);
中的increaseCount方法名称,并不是methods中定义的方法名称,而是store中定义的方法
4. 解决方案2
通过对比当前属性值和store状态值,然后根据比较结果,决定是否根据store状态管理规则更新状态值。
<script> import { mapState } from 'vuex'; export default { name: "displayCount", computed: { ...mapState({ count: state => state.a.count }) }, methods: { increaseCount () { if (this.count == this.$store.state.a.count) { this.$store.commit("increaseCount", this.count+1); } } } }; </script>
总结