vuex使用的简单例子

骑猪看日落 2023-02-22 12:16 137阅读 0赞

[vuex的基本知识讲解][vuex]

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store.js

import Vue from 'vue'
    import Vuex from 'vuex'
    Vue.use(Vuex)
    
    export const store = new Vuex.Store({ 
    	state: { 
    		lists: [{ 
    			id: 1,
    			name: '你好，Vuex',
    			money: 122
    		}]
    	},
    	getters: { 
    		lists2: (state) => { 
    			var numArr = state.lists.map(num => { 
    				return { 
    					id: new Date(),
    					name: "**" + num.name + "**",
    					money: num.money / 2
    				}
    			})
    			return numArr
    		}
    	},
    	mutations: { 
    		reducePriceM: (state, payload) => { 
    			state.lists.forEach(num => { 
    				num.money -= payload;
    			})
    		}
    	},
    	actions: { 
    	//payload是参数，可以是对象
    		reducePriceA: (context, payload) => { 
    			context.commit('reducePriceM', payload)
    		}
    	}
    })

调用方式如下：  
Test.vue

<template>
    	<div>
    		<div v-for="(item,index) in lists" :key="index">{ { item.name}} { { item.money}} </div>
    		<button @click="reducePriceA(4)">商品降价</button>
    	</div>
    </template>
    
    <script>
    	import { mapState,mapGetters,mapActions} from 'vuex'
    	export default { 
    		computed: { 
    			...mapState({ 
    				lists:state => state.lists
    			}),
    			...mapGetters([
    				"lists2"
    			])
    		},
    		methods: { 
    			...mapActions([
    				"reducePriceA"
    			])
    		}
    	}
    </script>
    
    <style>
    </style>

--------------------

如果没有写mapState，可以获取state中的属性值,

computed:{ 
    	lists() { 
    		console.log(this.$store)
    		return this.$store.state.lists
    	}
    }

--------------------

如果在store.js中没有写mapGetters，我们可以使用如下方式获取getters：

computed:{ 
    	lists2() { 
    		return this.$store.getters.lists2;
    	}
    }

--------------------

如果没有在store.js中写mutations:

computed:{ 
    	lists2() { 
    		var numArr = this.$store.state.lists.map(num => { 
    			return { 
    				id: new Date(),
    				name: "**"+num.name+"**",
    				money: num.money / 2
    			}
    		})
    		return numArr
    	}
    }

--------------------

没有写mapActions:可以使用如下：

methods：{ 
    	reducePriceX(amount) { 
    		/* this.$store.state.lists.forEach(num=>{ num.money-=1; }) */
    		 this.$store.commit('reducePrice')
    		this.$store.dispatch("reducePriceA", amount); //分发actions
    	}
    }

注意：  
对象展开运算符什么时候使用：  
**mapState、mapGetters、mapActions**

[vuex]: https://blog.csdn.net/lyx9611/article/details/106916420