drop-card.uvue

<template>
  <view class="root">
    <template v-for="(item,index) in cardList" :key="index">
      <view class="card" ref="card" @touchstart="touchstart($event as TouchEvent,index)" @touchmove="touchmove($event as TouchEvent,index)" @touchend="touchend" @touchcancel="touchend">
        <image class="card-img" ref="card-img" :src="item"></image>
        <view class="state">
          <image class="state-icon like" ref="state-icon-like" src="/static/template/drop-card/like.png" mode="widthFix"></image>
          <image class="state-icon dislike" ref="state-icon-dislike" src="/static/template/drop-card/dislike.png" mode="widthFix"></image>
        </view>
      </view>
    </template>
  </view>
</template>
<script lang="ts">
  let sX : number = 0,
    sY : number = 0,
    screenWidth : number = 1;
    
  export default {
    data() {
      return {
        x: 0 as number,
        y: 0 as number,
        cardList: [
          '/static/template/drop-card/1.jpg',
          '/static/template/drop-card/2.jpg',
          '/static/template/drop-card/3.jpg'
        ] as string[],
        // 页码
        currentIndex:0 as number,
        $nodesMap:new Map<string, INode[]>()
      }
    },
    onReady() {
      uni.getSystemInfo({
        success: (e) => {
          // console.log('e',e);
          screenWidth = e.screenWidth;
          let height = e.screenHeight - 200 + 'px'
          for (var i = 0; i < 3; i++) {
            this.setINodeStyle('card',i,'height', height);
            this.setINodeStyle('card-img',i,'height', height);
          }
        }
      })
      this.initCardList()
    },
    computed: {
      movePercent() : number {
        return Math.abs(this.x) / (screenWidth/2*3)
      },
      likeOpacity() : number {
        return this.x < 0 ? 0 : this.movePercent * 100
      },
      dislikeOpacity() : number {
        return this.x > 0 ? 0 : this.movePercent * 100
      },
      topCardIndex():number{
        return 2 - Math.abs(this.currentIndex)%3
      }
    },
    methods: {
      // 工具方法，用于快速设置 INode 的 style
      setINodeStyle(refName:string,index:number,propertyName:string,propertyStyle:any):void{
        let nodes:INode[]|null = this.$nodesMap.get(refName)
        if(nodes == null){
          nodes = this.$refs.get(refName) as INode[]
          this.$nodesMap.set(refName,nodes)
        }else{
          // console.log('直接拿');
        }
        (nodes)[index].style.setProperty(propertyName,propertyStyle);
      },
      // 设置卡片样式（层级，大小，上边距)
      initCardList(){
        for (var i = 0; i < 3; i++) {
          let endIndex = (i + this.currentIndex)%3
          this.setINodeStyle('card',i,'margin-top', 100 - 30*endIndex+'px');
          this.setINodeStyle('card',i,'transform', 'scale('+(0.9+0.05*endIndex)+')')
          // console.log(0.9+0.05*endIndex,50 - 20*endIndex+'px');
          this.setINodeStyle('card',i,'z-index', endIndex)
        }
      },
      moveCard() {
        for (var i = 0; i < 3; i++) {
          // 设置置顶卡片样式
          if(i === this.topCardIndex){
            this.setINodeStyle('card',this.topCardIndex,'transform', 'translateX('+this.x+'px) translateY('+this.y+'px) rotate('+this.x/-30+'deg) scale('+( 0.9+0.05*2 + movePercent/20 )+')')
            this.setINodeStyle('state-icon-like',this.topCardIndex,'opacity', x < 0 ? 0 : movePercent * 10)
            this.setINodeStyle('state-icon-dislike',this.topCardIndex,'opacity', x > 0 ? 0 : movePercent * 10)
          }else{
            let endIndex = (i + this.currentIndex)%3
            this.setINodeStyle('card',i,'transform', 'scale('+( 0.9+0.05*endIndex + movePercent*0.05 )+')')
            this.setINodeStyle('card',i,'margin-top', 100 - 30*endIndex - movePercent*30 +'px');
          }
        }
      },
      touchstart(e : TouchEvent,index:number) {
        if(index != this.topCardIndex){
          return 
        }
        sX = e.touches[0].screenX;
        sY = e.touches[0].screenY;
        this.x = 0
        this.y = 0
      },
      touchmove(e : TouchEvent,index:number) {
        if(index != this.topCardIndex){
          return 
        }
        this.x += e.touches[0].screenX - sX;
        this.y += e.touches[0].screenY - sY;
        sX = e.touches[0].screenX;
        sY = e.touches[0].screenY;
        this.moveCard()
      },
      touchend() {
        // console.log('touchend');

        // 设置释放之后飘走的方向 0回到坐标中心 1向右 2向左
        let k:number = 0;
        if (this.x > screenWidth / 6 ) {
          k = 1
        }else if(this.x < screenWidth * -1 / 6){
          k = -1
        }
        
        this.x = k * screenWidth * 1.5
        this.y = k * screenWidth * 0.5

        // 设置动画时间
        let transitionDuration = 300;
        let floatCardIndex = this.topCardIndex
        this.setINodeStyle('card',floatCardIndex,'transitionProperty','transform');
        this.setINodeStyle('card',floatCardIndex,'transitionDuration',transitionDuration);
        // this.setINodeStyle('card',floatCardIndex,'transitionOrigin','bottom center');
        this.moveCard()
         // 移动结束
        setTimeout(()=>{
          // 动画速度设置为0(即：关闭动画)
          this.setINodeStyle('card',floatCardIndex,'transitionDuration',0);
          
          if(this.x != 0.0){
              // 飘动的卡片挪回中心
              this.setINodeStyle('card',floatCardIndex,'transform', 'translate(0,0) rotate(0)')
              this.setINodeStyle('state-icon-like',floatCardIndex,'opacity', 0)
              this.setINodeStyle('state-icon-dislike',floatCardIndex,'opacity', 0)
              
              // 坐标归零
              this.x = 0
              this.y = 0
              
              // 动画改成marginTop,scale
              this.setINodeStyle('card',floatCardIndex,'transitionProperty','marginTop,scale');
              this.setINodeStyle('card',floatCardIndex,'transitionDuration',transitionDuration);
              // 切换卡片顺序
              this.currentIndex ++
              // 根据最新卡片顺序，设置层级大小样式
              this.initCardList()
          }
        },transitionDuration)
        
      }
    }
  }
</script>
<style>
  .root {
    flex: 1;
    position: relative;
  }

  .card {
    width: 700rpx;
    height: 750rpx;
    position: absolute;
    margin: 0 25rpx;
    margin-top: 50px;
    border-radius: 10px;
    color: #FFF;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.1);
    background-color: #FFF;
    /* transform-origin:bottom; */
    transition:margin-top 60ms;
    transition-timing-function: ease-in;
  }
  
  .card-img {
    border-radius: 10px;
  }

  .state {
    top: 20rpx;
    left: 20rpx;
    width: 650rpx;
    padding: 4px;
    position: absolute;
    flex-direction: row;
    justify-content: space-between;
  }
  
  .state-icon {
    width: 30px;
    height: 30px;
    border: 1px solid #FFF;
    background-color: #FFF;
    padding: 3px;
    border-radius: 100px;
    box-shadow: 0 0 1px #EBEBEB;
    opacity: 0;
  }
  
</style>