HarmonyOS 如何把网络链接的视频或者图片保存到本地相册

http.request几口上传最大可支持5m数据传递，如需要传递大于5m的数据可使用requestInstream采用流式接口能力，使用可参考如下：

let httpRequest = http.createHttp();
httpRequest.on("dataReceiveProgress", (data: http.DataReceiveProgressInfo) => {
  console.info("dataReceiveProgress:" + JSON.stringify(data));
});
httpRequest.on("dataReceive", (data: ArrayBuffer) => {
  console.info("dataReceive length: " + JSON.stringify(data.byteLength));
});
httpRequest.on("dataEnd", () => {
  console.info("Receive dataEnd !");
});
httpRequest.requestInStream("https://xx.jpg",
  (err: BusinessError, data: number) => {
    if (!err) {
      console.info("ResponseCode is " + JSON.stringify(data));
    } else {
      console.info("requestInStream ERROR : err = " + JSON.stringify(err));
    }
  })

推荐使用rcponDataReceive

参考链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/remote-communication-rcp-V5#section9264115918536