uniapp 读取文件 ArrayBuffer 获取 SHA 值，兼容 H5、小程序、APP

uniapp-arraybuffer-sha256.ts

import { lib as CryptoLib, SHA256 } from 'crypto-js'

const arrayBufferToWordArray = (ab: any) => {
  const i8a = new Uint8Array(ab)
  const a = []
  for (let i = 0; i < i8a.length; i += 4) {
    a.push((i8a[i] << 24) | (i8a[i + 1] << 16) | (i8a[i + 2] << 8) | i8a[i + 3])
  }
  return CryptoLib.WordArray.create(a, i8a.length)
}

// #ifdef H5
// 通过blob:url读取实际的blob数据
// 参考：https://ask.dcloud.net.cn/question/75697
const blobURLToBlob = (url: string) => {
  return new Promise((resolve, reject) => {
    var http = new XMLHttpRequest()
    http.open('GET', url, true)
    http.responseType = 'blob'
    http.onload = function (e) {
      if (this.status == 200 || this.status === 0) {
        resolve(this.response)
      } else {
        reject(this.status)
      }
    }
    http.send()
  })
}

//  通过blob:url读取实际的ArrayBuffer数据
const h5ReadBlobUrlArrayBuffer = (blobUrl: string) => {
  return new Promise(async (resolve, reject) => {
    try {
      const reader = new FileReader()
      // blob数据转file对象数据
      const fileBlob: any = await blobURLToBlob(blobUrl)
      const file = new window.File([fileBlob], 'file.name', { type: 'file.type' })
      // 读取file对象ArrayBuffer
      reader.readAsArrayBuffer(file)
      reader.onload = function (e) {
        resolve(e?.target?.result)
      }
    } catch (e) {
      reject(e)
    }
  })
}
// #endif

// #ifdef APP-PLUS
// 通过plus.io读取文件的ArrayBuffer数据
const h5PlusReadFileArrayBuffer = (filePath: string) => {
  return new Promise((resolve, reject) => {
    try {
      plus.io.resolveLocalFileSystemURL(
        filePath,
        function (entry: any) {
          entry?.file(function (file: any) {
            // @ts-ignore
            const fileReader = new plus.io.FileReader()
            fileReader.readAsDataURL(file, 'utf-8')
            fileReader.onloadend = function (evt: any) {
              const result = {
                // 参考：https://www.freesion.com/article/40591516652/
                base64: evt.target.result.split(',')[1],
                size: file.size,
              }
              resolve(uni.base64ToArrayBuffer(result.base64))
            }
          })
        },
        function (error) {
          reject(error)
        },
      )
    } catch (error) {
      reject(error)
    }
  })
}
// #endif

const getFileArrayBuffer = async (filePath: string) => {
  if (uni.canIUse('getFileSystemManager') && uni.getFileSystemManager) {
    const fs = uni.getFileSystemManager()
    return fs.readFileSync(filePath)
  }
  // #ifdef APP-PLUS
  else if (plus.io) {
    return h5PlusReadFileArrayBuffer(filePath)
  }
  // #endif
  // #ifdef H5
  else if (XMLHttpRequest) {
    return h5ReadBlobUrlArrayBuffer(filePath)
  }
  // #endif
  else {
    throw new Error('不支持的平台')
  }
}

export const getFileSha256 = async (filePath: string) => {
  if (!filePath) return Promise.reject('缺少文件路径')
  const arrayBuffer = await getFileArrayBuffer(filePath)
  return SHA256(arrayBufferToWordArray(arrayBuffer)).toString()
}