在vue中,父组件值传另外一个子组件怎么不行?

为啥子组件向父组件传值是成功的,但是父组件向另外一个组件传值就没有成功
我的思路是在info-swiper中点击左侧箭头,把num值传给父组件,然后父组件拿到num值(到这里成功了),传给info-infor页面,达到该页面num值的变化。
后面这步失败了,但是我给info-infor的属性inforNum 给个Number定值,在子页面是对的
有三个页面,父组件 _id,1子组件 info-swiper,2子组件 info-infor

<section class="layout-info-content clearfloat">
       <section class="layout-info-swiper">
          <info-swiper :items='infoSwiperUl' @swiperPre='swiperPreNum' @swiperNext='swiperNext' :swiperNumber='swiperNum'></info-swiper>
       </section>
       <section class="layout-info-right">
          <info-infor :items='infoSwiperUl' :listNum=inforNum @handeleClickIndex='inforIndex'></info-infor>
       </section>
   </section>
data () {
    return {
      inforNum:0,
      swiperNum:0,
    }
}
methods:{
    swiperPreNum (num) {
      this.inforNum = num
      console.log(num,'swiperPreNum',this.inforNum)
    },
    swiperNext(num){
      this.inforNum = num
      console.log(num,'swiperNext',this.inforNum)
    },
    inforIndex(num) {
      this.swiperNum=num
      console.log(num,'inforIndex',this.swiperNum)
    }
  },

1子组件 info-swiper handlePre是上一个 handleNext是下一个

name:'InfoSwiper',
     props:{
       items:{
         type:Object,
         default:null
       },
       swiperNumber:{
         type:Number,
         default:0
       }
     },
     data () {
       return {
         swiperList:null,
         swiperNum:0
       }
     },
     created(){
       this.swiperNum=this.swiperNumber
       console.log(this.swiperNum)
    },
methods:{
      handlePre(){
        let num= this.swiperNum
        if(num<1){
          num=this.items.imgArr.length-1
          this.swiperNum =num
        }else{
          num--
          this.swiperNum =num
        }
        // console.log(this.swiperNum,"handlePre")
        this.$emit('swiperPre',this.swiperNum)
      },
      handleNext (){
        let num= this.swiperNum
        if(num>17){
          this.swiperNum =0
        }else{
          num++
          this.swiperNum =num
        }
        // console.log(this.swiperNum,"handleNext")
        this.$emit('swiperNext',this.swiperNum)
      },
    }