async startAuth() {
  const httpRequest = http.createHttp()
  const tokenUrl =
    `https://api.weixin.qq.com/cgi-bin/token?appid=${APP_ID}&secret=${APP_SECRET}&grant_type=client_credential`
  try {
    const data = await httpRequest.request(tokenUrl)
    const tokenJson: Record<string, Object> = JSON.parse(data.result as string)
    const token = tokenJson['access_token'] as string
    console.info('onAuthError token: ' +  token)
    const ticketUrl = `https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=${token}&type=2`
    const ticketData = await httpRequest.request(ticketUrl)
    const ticketJson: Record<string, Object> = JSON.parse(ticketData.result as string)
    const ticket = ticketJson['ticket'] as string
    console.info('onAuthError ticket: ' +  ticket)
    const signature = await this.getSignature(APP_ID, ticket, 'noncestr', 'timestamp')
    console.info('onAuthError signature: ' +  signature)
    const callback: wxopensdk.OAuthCallback = {
      onGotQRCode: (base64JpegImageBuffer: string) => {
        this.base64ImageBuffer = `data:image/jpeg;base64,${base64JpegImageBuffer}`
        this.loadStatus = LoadingStatus.SCANNING
      },
      onQRCodeScanned: () => {
        this.loadStatus = LoadingStatus.SCANNED
      },
      onAuthFinish: (authCode: string) => {
        this.loadStatus = LoadingStatus.SUCCESS
        this.wxCode = authCode
      },
      onAuthError: (errCode: wxopensdk.OAuthErrCode, errMsg: string) => {
        console.info('onAuthError errCode:', errCode, 'errMsg:', errMsg)
        this.loadStatus = LoadingStatus.FAILED
        this.errStr = `errCode: ${errCode}, errMsg: ${errMsg}`
      }
    }
    if (this.lastOAuth) {
      this.lastOAuth.stopOAuth()
    }
    let oauth = wxopensdk.DiffDevOAuthFactory.getDiffDevOAuth()!
    this.lastOAuth = oauth
    let scope = "snsapi_login,snsapi_friend,snsapi_message,snsapi_contact"
    oauth.startOAuth(APP_ID, scope, 'noncestr', 'timestamp', signature, callback)
  } catch (err) {
    console.error('request error:', err)
    this.loadStatus = LoadingStatus.FAILED
    this.errStr = ' 网络请求失败'
  }
}