浅谈Vue的组件间传值(包括Vuex)

<template>
    <div>
        <HELLOWORLD :needData="content"></HELLOWORLD>
    </div>
</template>

<script>
import HELLOWORLD from '../components/HelloWorld.vue'
export default {
    components:{
        HELLOWORLD
    },
    data(){
        return{
            content:"content"
        }
    }
}
</script>

<style lang="less" scoped>

</style>

<template>
    <div>
        <h1>HELLOWORLD</h1>
    </div>
</template>

<script>
export default {
    props:["needData"],
    data(){
        return{
            H:this.needData,
        }
    },
    mounted(){
        console.log(this.H);
    }
}
</script>

<style lang="less" scoped>

</style>

<template>
    <div>
        <HELLOWORLD @sendData="getData"></HELLOWORLD>
    </div>
</template>

<script>
import HELLOWORLD from '../components/HelloWorld.vue'
export default {
    components:{
        HELLOWORLD
    },
    data(){
        return{
            
        }
    },
    methods:{
        getData(sonData){
            console.log("data=>",sonData);
        },
    }
}
</script>

<style lang="less" scoped>

</style>

<template>
    <div>
        <h1>HELLOWORLD</h1>
    </div>
</template>

<script>
export default {
    data(){
        return{
            content:"content"
        }
    },
    mounted(){
        this.$emit("sendData",this.content);
    }
}
</script>

<style lang="less" scoped>

</style>

let a={
  state: {
  	name:"moduleA"
  },
  //mutations专门用于改变state属性中的数据
  mutations: {
  	setFun(state,item){
		state.name=item;
	}
  }
}

export default new Vuex.Store({
  //state专门存放数据
  state: {
  	num:100,
  	useAcomponent:{
		name:"A",
	},
	useBcomponent:"content",
  },
  //mutations专门用于改变state属性中的数据
  mutations: {
  	setStateFun(state,item){
		state.useBcomponent="Bcomponent";
	}
  },
  actions: {
  	httpGetData(store,item){
		setTimeout(()=>{
			console.log(item);
			store.commit("setStateFun",item);
		},3000)
	}
  },
  getters:{
  //调用getters中的函数时没有入参
	getterFun1(state){
		return state.num++
	}
  //调用getters中的函数时有入参
  	gettterFun2(state){
		return function(val){
			return state.num+=val;
		}
	}
  },
  modules: {
  	ModuleA:a
  }
});
}

this.$store.state.state对象中的数据;
例如
let val=this.$store.state.num;

this.$store.commit("函数名","数据");
例如
this.$store.commit("setStateFun","testSetItem");

this.$store.dispatch("函数名","数据");
例如
this.$store.dispatch("httpGetData","testItem");

this.$store.getters.函数名;
例如
//没入参时
this.$store.getters.getterFun1;
//有入参时
this.$store.getters.getterFun2(123);

//获取modules对象中的state数据
this.$store.state.modules对象名.state值;
例如
this.$store.state.ModuleA.name
//使用modules对象中的mutations的函数
this.$store.commit("函数名","入参数据");
例如
this.$store.commit("setFun","itemabc");
//这里需要注意，如果modules模块中与外部(不是modules对象模块)的mutations对象中有相同名字的函数时，则相同名字的函调用时都会执行