Problem: in Android qq browser, v-lazy-image cannot be displayed all the time.

Cause analysis:

After debugging, it is found that the IntersectionObserver in the qq browser lacks an isIntersecting field, while the v-lazy-image plug-in displays pictures according to isIntersecting, so it can only be judged by using intersectionRatio.

Another difference is that if the initial width and height of the v-lazy-image component is 0, the intersectionRatio will always be 0.

Solution:

Modify and customize a vue plug-in module based on the v-lazy-image source code. See the end of the article for the code.

When v-lazy-image is used, set SRC placeholder to ensure that v-lazy-image has an initial size. Here I randomly make a 1x1 blank image. The example code is as follows

Modify main.js

import { VLazyImagePlugin } from './plugins/VLazyImage'
// polyfill
require('intersection-observer')
Vue.use(VLazyImagePlugin)

Components:

<template>
	<div>
		<v-lazy-image :src="product_image" :src-placeholder="lazyPlaceholder"/>
		<v-lazy-image :src="product_image" :src-placeholder="lazyPlaceholder"/>
		<v-lazy-image :src="product_image" :src-placeholder="lazyPlaceholder"/>
	</div>
</template>
<script>
export default {
	data () {
		product_image: 'http://img.alicdn.com/imgextra/i1/3990548613/O1CN01VxNcOn2DUnnBu8jIW_!!0-item_pic.jpg',
		lazyPlaceholder: require('./lazy-placeholder.png')
	},
	mounted () {
		// ...
	}
}
</script>

Source code of the modified plug-in: plugins/VLazyImage

const VLazyImageComponent = {
  props: {
    src: {
      type: String,
      required: true
    },
    srcPlaceholder: {
      type: String,
      default: ''
    },
    srcset: {
      type: String
    },
    intersectionOptions: {
      type: Object,
      default: () => ({})
    },
    usePicture: {
      type: Boolean,
      default: false
    }
  },
  inheritAttrs: false,
  data: () => ({ observer: null, intersected: false, loaded: false }),
  computed: {
    srcImage () {
      return this.intersected ? this.src : this.srcPlaceholder
    },
    srcsetImage () {
      return this.intersected && this.srcset ? this.srcset : false
    }
  },
  methods: {
    load () {
      if (this.$el.getAttribute('src') !== this.srcPlaceholder) {
        this.loaded = true
        this.$emit('load')
      }
    }
  },
  render (h) {
    let img = h('img', {
      attrs: {
        src: this.srcImage,
        srcset: this.srcsetImage
      },
      domProps: this.$attrs,
      class: {
        'v-lazy-image': true,
        'v-lazy-image-loaded': this.loaded
      },
      on: { load: this.load }
    })
    if (this.usePicture) {
      return h('picture', { on: { load: this.load } }, this.intersected ? [ this.$slots.default, img ] : [])
    } else {
      return img
    }
  },
  mounted () {
    if ('IntersectionObserver' in window) {
      this.observer = new IntersectionObserver(entries => {
        const image = entries[0]
        if (image.isIntersecting || image.intersectionRatio) {
          this.intersected = true
          this.observer.disconnect()
          this.$emit('intersect')
        }
      }, this.intersectionOptions)
      this.observer.observe(this.$el)
    } else {
      console.error(
        "v-lazy-image: this browser doesn't support IntersectionObserver. Please use this polyfill to make it work https://github.com/w3c/IntersectionObserver/tree/master/polyfill."
      )
    }
  },
  destroyed () {
    this.observer.disconnect()
  }
}

export default VLazyImageComponent

export const VLazyImagePlugin = {
  install: (Vue, opts) => {
    Vue.component('VLazyImage', VLazyImageComponent)
  }
}