前端使用Compressor.js实现图片压缩上传的详细过程

npm install compressorjs

<template>
  <div>
    <van-uploader
      :max-count="prop.limit"
      v-model="state.fileList"
      :after-read="afterRead"
      :before-read="beforeRead"
      @delete="deleteFile"
    />
  </div>
</template>
<script setup>
import { reactive, defineEmits, defineProps, watch } from 'vue'
import { FileUploadFun } from '@/api/index.js'
import { useCustomFieldValue } from '@vant/use'
import { Toast } from 'vant'
import Compressor from 'compressorjs'

const prop = defineProps({
  url: {
    type: String,
    default: '',
  },
  limit: {
    type: Number,
    default: 5,
  },
})
const emit = defineEmits(['onSuccess'])
const state = reactive({
  fileList: [],
})

watch(
  () => prop.url,
  () => {
    if (prop.url) {
      state.fileList = []
      prop.url.split(',').forEach((item) => {
        state.fileList.push({
          url: item,
        })
      })
    }
  }
)

// 文件上传之前对图片进行压缩
const beforeRead = (file) => {
  return new Promise((resolve, reject) => {
    new Compressor(file, {
      // 压缩质量，0-1之间。数字越小，压缩比越高
      quality: 0.2,
      success(result) {
        // 默认返回result是blob类型的文件，可以转成file并返回，交给afterRead钩子进行上传
        let newFile = new File([result], file.name, { type: file.type })
        resolve(newFile)
      },
      error(err) {
        reject(err)
      },
    })
  })
}

// 文件上传后触发
const afterRead = (file) => {
  file.status = 'uploading'
  file.message = '上传中...'

  FileUploadFun(file.file)
    .then((res) => {
      file.status = 'done'
      file.message = '上传成功'
      let urls = state.fileList.map((i) => i.url)
      urls.pop()
      urls.push(res.data.url)
      // 通知外界上传成功
      emit('onSuccess', urls.join(','))
    })
    .catch(() => {
      state.fileList.pop()
      file.status = 'done'
      Toast('上传失败')
    })
}

// 文件删除后触发
const deleteFile = () => {
  emit('onSuccess', state.fileList.map((i) => i.url).join(','))
}

// 用于返回信息
useCustomFieldValue(() => state.fileList.map((item) => item.url).join(','))
</script>