uni-app 同时上传多个文件

最近在用uni-app写项目的时候 有业务需要同时上传多张图片给后台，但查了官方文档，发现uni.uploadFile() 虽然可以通过 files 参数上传多个文件，但是只支持APP和H5。

我的项目主要针对的是微信小程序，所以看了很多文章，找到如下两种方式，可以参考一下

方案一：使用 uni.uploadFile() 轮询上传

使用 uni.chooseMedia 成功后会返回 本地临时文件列表 可以参考官方文档 uni.chooseMedia()

uni.chooseMedia({
  mediaType: ['image'],
  sourceType: ['album'],
  success: (res) => {
    const { tempFiles } = res
    	// uploadFile 方法为自己封装的上传方法
    	uploadFile(tempFiles)
    },
  fail: () => {
      console.log('fail')
    },
  complete: () => {
      // console.log('complete')
    },
  })

成功后调用自己写的 uploadFile

const uploadFile = (files:any[]) => {
  const uploadTasks = files.map((file: any, index: number) => {
     return new Promise((resolve, reject) => {
     	const uploadTask = uni.uploadFile({
        url: 'https://www.xxx.cn/v1/wxInvoice/upload', // 接口地址
        filePath: file.tempFilePath, // 临时文件路径
        name: 'files[]', // 服务器接收的文件字段名(这个地方很重要要和后端沟通一下)
        header: {
        	Authorization: 'Bearer ' + token.value,
          	'Content-Type': 'multipart/form-data',
        },
        formData: {
          // 可以在这里添加额外的formData参数
         },
        success: function (res) {
           resolve(res.data)
         },
         fail: function (err) {
         	reject(err)
         },
     })
	  
	 // 这里可以根据需要显示进度条
     uploadTask.onProgressUpdate((res) => {
     console.log('上传进度', res.progress)
     console.log('已经上传的数据长度', res.totalBytesSent)
     console.log('预期需要上传的数据总长度', res.totalBytesExpectedToSend)

    })
  })
})

Promise.all(uploadTasks)
     .then((res) => {
      console.log('上传成功', res)
       // 上传成功后的操作
     })
     .catch((err) => {
       console.log('上传失败', err)
      // 上传失败后的操作
     })
}

方案二

使用 wx-formdata 库，当然我这里是uni-app + ts 项目，所以我把这个库里的 formData.js 和 mimeMap.js 库进行了修改，文章结尾看(不要介意代码质量,能跑就行)

使用

uni.chooseMedia({
  mediaType: ['image'],
  sourceType: ['album'],
  success: (res) => {
    const { tempFiles } = res
    	
    	const formData = new FormData()
		
		// 非文件用 append()方法
		// 文件用 appendFile()方法
  		// 需要遍历将文件加入到formData中(这里是我的需求,可自定义)
  		for (let i = 0; i < tempFiles .length; i++) {
    		formData.appendFile('files[' + i + ']', tempFiles [i].tempFilePath)
  		}
  		const data = formData.getData()
		
		// 调用接口传递数据
		uni.request({
			url: '接口地址',
    		method: 'post',
    		data: data.buffer,
    		header: { 'Content-Type': data.contentType },
    		success:() => {
    			//...
    		}
		})
    },
  fail: () => {
      console.log('fail')
    },
  complete: () => {
      // console.log('complete')
    },
})

以下是修改过的文件
formData.ts

import mimeMap from './mimeMap'

interface CommonFormData {
  fileManager: any
  data: any
  files: any

  append(name: string, value: any): boolean
  appendFile(name: string, path: any, fileName?: any): boolean
  getData(): any
}

class FormData implements CommonFormData {
  fileManager: any
  data: any
  files: any

  constructor() {
    this.fileManager = uni.getFileSystemManager()
    this.data = {}
    this.files = []
  }

  append(name: string, value: any) {
    this.data[name] = value
    return true
  }

  appendFile(name: string, path: any, fileName?: any) {
    let buffer = this.fileManager.readFileSync(path)
    if (Object.prototype.toString.call(buffer).indexOf('ArrayBuffer') < 0) {
      return false
    }
    if (!fileName) {
      fileName = getFileNameFromPath(path)
    }
    this.files.push({
      name: name,
      buffer: buffer,
      fileName: fileName,
    })
    return true
  }

  getData() {
    return convert(this.data, this.files)
  }
}

function getFileNameFromPath(path: any) {
  let idx = path.lastIndexOf('/')
  return path.substr(idx + 1)
}

function convert(data: any, files: any) {
  let boundaryKey = 'unimpFormBoundary' + randString() // 数据分割符，一般是随机的字符串
  let boundary = '--' + boundaryKey
  let endBoundary = boundary + '--'

  let postArray: any = []
  //拼接参数
  if (data && Object.prototype.toString.call(data) == '[object Object]') {
    for (let key in data) {
      postArray = postArray.concat(formDataArray(boundary, key, data[key]))
    }
  }
  //拼接文件
  if (files && Object.prototype.toString.call(files) == '[object Array]') {
    for (let i in files) {
      let file = files[i]
      postArray = postArray.concat(formDataArray(boundary, file.name, file.buffer, file.fileName))
    }
  }

  //结尾
  let endBoundaryArray = []
  endBoundaryArray.push(...endBoundary.toUtf8Bytes())
  postArray = postArray.concat(endBoundaryArray)

  return {
    contentType: 'multipart/form-data; boundary=' + boundaryKey,
    buffer: new Uint8Array(postArray).buffer,
  }
}

// 获取随机字符串
function randString() {
  var result = ''
  var chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
  for (var i = 17; i > 0; --i) result += chars[Math.floor(Math.random() * chars.length)]
  return result
}

function formDataArray(boundary: any, name: string, value: any, fileName?: string) {
  let dataString: any = ''
  let isFile = !!fileName

  dataString += boundary + '\r\n'
  dataString += 'Content-Disposition: form-data; name="' + name + '"'
  if (isFile) {
    dataString += '; filename="' + fileName + '"' + '\r\n'
    dataString += 'Content-Type: ' + getFileMime(fileName || '') + '\r\n\r\n'
  } else {
    dataString += '\r\n\r\n'
    dataString += value
  }

  var dataArray = []
  dataArray.push(...dataString.toUtf8Bytes())

  if (isFile) {
    let fileArray = new Uint8Array(value)
    dataArray = dataArray.concat(Array.prototype.slice.call(fileArray))
  }
  dataArray.push(...'\r'.toUtf8Bytes())
  dataArray.push(...'\n'.toUtf8Bytes())

  return dataArray
}

function getFileMime(fileName: string) {
  let idx = fileName.lastIndexOf('.')
  let index: string = fileName.substr(idx)
  let mime = mimeMap[index]
  return mime ? mime : 'application/octet-stream'
}

function stringToUtf8(string: string) {
  let encoder = new TextEncoder()
  return encoder.encode(string)
}

String.prototype.toUtf8Bytes = function () {
  var str: any = this
  var bytes = []
  for (var i = 0; i < str.length; i++) {
    bytes.push(...str.utf8CodeAt(i))
    if (str.codePointAt(i) > 0xffff) {
      i++
    }
  }
  return bytes
}

String.prototype.utf8CodeAt = function (i: any) {
  var str = this
  var out = [],
    p = 0
  var c = str.charCodeAt(i)
  if (c < 128) {
    out[p++] = c
  } else if (c < 2048) {
    out[p++] = (c >> 6) | 192
    out[p++] = (c & 63) | 128
  } else if ((c & 0xfc00) == 0xd800 && i + 1 < str.length && (str.charCodeAt(i + 1) & 0xfc00) == 0xdc00) {
    // Surrogate Pair
    c = 0x10000 + ((c & 0x03ff) << 10) + (str.charCodeAt(++i) & 0x03ff)
    out[p++] = (c >> 18) | 240
    out[p++] = ((c >> 12) & 63) | 128
    out[p++] = ((c >> 6) & 63) | 128
    out[p++] = (c & 63) | 128
  } else {
    out[p++] = (c >> 12) | 224
    out[p++] = ((c >> 6) & 63) | 128
    out[p++] = (c & 63) | 128
  }
  return out
}

export default FormData

mimeMap.ts

const mimeMap:{[key:string]:any = {
	// 此处省略...
	// 把一些重复的处理一下
}

formData.d.ts

interface String {
  toUtf8Bytes(): any
  utf8CodeAt(i:any): any
}

以上就是我的分享，有问题留言