<template> 
 | 
  <view class="tn-lazy-load-class tn-lazy-load"> 
 | 
    <view 
 | 
      class="tn-lazy-load__item" 
 | 
      :class="[`tn-lazy-load__item--${elIndex}`]" 
 | 
      :style="[lazyLoadItemStyle]" 
 | 
    > 
 | 
      <view class="tn-lazy-load__item__content"> 
 | 
        <image 
 | 
          v-if="!error" 
 | 
          class="tn-lazy-load__item__image" 
 | 
          :style="[imageStyle]" 
 | 
          :src="show ? image : loadingImg" 
 | 
          :mode="imgMode" 
 | 
          @load="handleImgLoaded" 
 | 
          @error="handleImgError" 
 | 
          @tap="handleImgClick" 
 | 
        ></image> 
 | 
        <image 
 | 
          v-else 
 | 
          class="tn-lazy-load__item__image tn-lazy-load__item__image--error" 
 | 
          :style="[imageStyle]" 
 | 
          :src="errorImg" 
 | 
          :mode="imgMode" 
 | 
          @load="handleErrorImgLoaded" 
 | 
          @tap="handleImgClick" 
 | 
        ></image> 
 | 
      </view> 
 | 
    </view> 
 | 
  </view> 
 | 
</template> 
 | 
  
 | 
<script> 
 | 
  export default { 
 | 
    name: 'tn-lazy-load', 
 | 
    props: { 
 | 
      // 组件标识 
 | 
      index: { 
 | 
        type: [String, Number], 
 | 
        default: '' 
 | 
      }, 
 | 
      // 待显示的图片地址 
 | 
      image: { 
 | 
        type: String, 
 | 
        default: '' 
 | 
      }, 
 | 
      // 图片裁剪模式 
 | 
      imgMode: { 
 | 
        type: String, 
 | 
        default: 'scaleToFill' 
 | 
      }, 
 | 
      // 占位图片路径 
 | 
      loadingImg: { 
 | 
          type: String, 
 | 
          // default: 'data:image/png;base64,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' 
 | 
      }, 
 | 
      // 加载失败的错误占位图 
 | 
      errorImg: { 
 | 
          type: String, 
 | 
          default: 'data:image/png;base64,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' 
 | 
      }, 
 | 
      // 图片进入可见区域前多少像素前,单位rpx,开始加载图片 
 | 
      // 负数为图片超出屏幕底部多少像素后触发懒加载,正数为图片顶部距离屏幕底部多少距离时触发(图片还没出现在屏幕上) 
 | 
      threshold: { 
 | 
        type: [Number, String], 
 | 
        default: 100 
 | 
      }, 
 | 
      // 是否开启过渡效果 
 | 
      isEffect: { 
 | 
        type: Boolean, 
 | 
        default: true 
 | 
      }, 
 | 
      // 动画过渡时间 
 | 
      duration: { 
 | 
        type: [String, Number], 
 | 
        default: 500 
 | 
      }, 
 | 
      // 渡效果的速度曲线,各个之间差别不大,因为这是淡入淡出,且时间很短,不是那些变形或者移动的情况,会明显 
 | 
      // linear|ease|ease-in|ease-out|ease-in-out|cubic-bezier(n,n,n,n); 
 | 
      effect: { 
 | 
          type: String, 
 | 
          default: 'ease-in-out' 
 | 
      }, 
 | 
      // 图片高度,单位rpx 
 | 
      height: { 
 | 
        type: [String, Number], 
 | 
        default: 450 
 | 
      }, 
 | 
      // 图片圆角 
 | 
      borderRadius: { 
 | 
        type: String, 
 | 
        default: '' 
 | 
      } 
 | 
    }, 
 | 
    computed: { 
 | 
      thresholdValue() { 
 | 
        // 先取绝对值,因为threshold可能是负数,最后根据this.threshold是正数或者负数,重新还原 
 | 
        let threshold = uni.upx2px(Math.abs(this.threshold)) 
 | 
        return this.threshold < 0 ? -threshold : threshold 
 | 
      }, 
 | 
      lazyLoadItemStyle() { 
 | 
        let style = {} 
 | 
        style.opacity = Number(this.opacity) 
 | 
        if (this.borderRadius) { 
 | 
          style.borderRadius = this.borderRadius 
 | 
        } 
 | 
        // 因为time值需要改变,所以不直接用duration值(不能改变父组件prop传过来的值) 
 | 
        style.transition = `opacity ${this.time / 1000}s ${this.effect}` 
 | 
        style.height = this.$t.string.getLengthUnitValue(this.height) 
 | 
        return style 
 | 
      }, 
 | 
      imageStyle() { 
 | 
        let style = {} 
 | 
        if (typeof this.height === 'string' && this.height.indexOf('%') === -1) { 
 | 
          style.height = this.$t.string.getLengthUnitValue(this.height) 
 | 
        } 
 | 
        return style 
 | 
      } 
 | 
    }, 
 | 
    watch: { 
 | 
      show(val) { 
 | 
        // 如果不开启过渡效果直接返回 
 | 
        if (!this.effect) return 
 | 
        this.time = 0 
 | 
        // 原来opacity为1(不透明,是为了显示占位图),改成0(透明,意味着该元素显示的是背景颜色,默认的白色),再改成1,是为了获得过渡效果 
 | 
        this.opacity = 0 
 | 
        setTimeout(() => { 
 | 
          this.time = this.duration 
 | 
          this.opacity = 1 
 | 
        }, 30) 
 | 
      }, 
 | 
      image(val) { 
 | 
        // 修改图片后重置部分变量 
 | 
        if (!val) { 
 | 
          // 如果传入null或者'',或者undefined,标记为错误状态 
 | 
          this.error = true 
 | 
        } else { 
 | 
          this.init() 
 | 
          this.error = false 
 | 
        } 
 | 
      } 
 | 
    }, 
 | 
    data() { 
 | 
      return { 
 | 
        elIndex: this.$t.uuid(), 
 | 
        // 显示图片 
 | 
        show: false, 
 | 
        // 图片透明度 
 | 
        opacity: 1, 
 | 
        // 动画时间 
 | 
        time: this.duration, 
 | 
        // 懒加载状态 
 | 
        // loadlazy-懒加载中状态,loading-图片正在加载,loaded-图片加加载完成 
 | 
        loadStatus: '', 
 | 
        // 图片加载失败 
 | 
        error: false 
 | 
      } 
 | 
    }, 
 | 
    created() { 
 | 
      // 由于一些特殊原因,不能将此变量放到data中定义 
 | 
      this.observer = {} 
 | 
      this.observerName = 'lazyLoadContentObserver' 
 | 
    }, 
 | 
    mounted() { 
 | 
      // 在需要用到懒加载的页面,在触发底部的时候触发tOnLazyLoadReachBottom事件,保证所有图片进行加载 
 | 
      this.$nextTick(() => { 
 | 
        uni.$once('tOnLazyLoadReachBottom', () => { 
 | 
          if (!this.show) this.show = true 
 | 
        }) 
 | 
      }) 
 | 
      // mounted的时候,不一定挂载了这个元素,延时30ms,否则会报错或者不报错,但是也没有效果 
 | 
      setTimeout(() => { 
 | 
        this.disconnectObserver(this.observerName) 
 | 
        const contentObserver = uni.createIntersectionObserver(this) 
 | 
        contentObserver.relativeToViewport({ 
 | 
          bottom: this.thresholdValue 
 | 
        }).observe(`.tn-lazy-load__item--${this.elIndex}`, (res) => { 
 | 
          if (res.intersectionRatio > 0) { 
 | 
            // 懒加载状态改变 
 | 
            this.show = true 
 | 
            // 如果图片已经加载,去掉监听,减少性能消耗 
 | 
            this.disconnectObserver(this.observerName) 
 | 
          } 
 | 
        }) 
 | 
        this[this.observerName] = contentObserver 
 | 
      }, 50) 
 | 
    }, 
 | 
    methods: { 
 | 
      // 初始化 
 | 
      init() { 
 | 
        this.error = false 
 | 
        this.loadStatus = '' 
 | 
      }, 
 | 
      // 处理图片点击事件 
 | 
      handleImgClick() { 
 | 
        let whichImg = '' 
 | 
        // 如果show为false,则表示图片还没有开始加载,点击的是最开始占位图 
 | 
        if (this.show === false) whichImg = 'lazyImg' 
 | 
        // 如果error为true,则表示图片加载失败,点击的是错误占位图 
 | 
        else if (this.error === true) whichImg = 'errorImg' 
 | 
        // 点击了正常的图片 
 | 
        else whichImg = 'realImg' 
 | 
         
 | 
        this.$emit('click', { 
 | 
          index: this.index, 
 | 
          whichImg: whichImg 
 | 
        }) 
 | 
      }, 
 | 
      // 处理图片加载完成事件,通过show来区分是占位图触发还是加载真正的图片触发 
 | 
      handleImgLoaded() { 
 | 
        if (this.loadStatus = '') { 
 | 
          // 占位图加载完成 
 | 
          this.loadStatus = 'lazyed' 
 | 
        } 
 | 
        else if (this.loadStatus == 'lazyed') { 
 | 
          // 真正的图片加载完成 
 | 
          this.loadStatus = 'loaded' 
 | 
          this.$emit('loaded', this.index) 
 | 
        } 
 | 
      }, 
 | 
      // 处理错误图片加载完成 
 | 
      handleErrorImgLoaded() { 
 | 
        this.$emit('error', this.index) 
 | 
      }, 
 | 
      // 处理图片加载失败 
 | 
      handleImgError() { 
 | 
        this.error = true 
 | 
      }, 
 | 
      disconnectObserver(observerName) { 
 | 
        const observer = this[observerName] 
 | 
        observer && observer.disconnect() 
 | 
      } 
 | 
    } 
 | 
  } 
 | 
</script> 
 | 
  
 | 
<style lang="scss" scoped> 
 | 
  .tn-lazy-load { 
 | 
    &__item { 
 | 
      background-color: $tn-bg-gray-color; 
 | 
      overflow: hidden; 
 | 
       
 | 
      &__image { 
 | 
        // 解决父容器会多出3px的问题 
 | 
        display: block; 
 | 
        width: 100%; 
 | 
        // 骗系统开启硬件加速 
 | 
        transform: transition3d(0, 0, 0); 
 | 
        // 防止图片加载“闪一下” 
 | 
        will-change: transform; 
 | 
      } 
 | 
    } 
 | 
  } 
 | 
</style> 
 |