android - 如何在不增加大小的情况下将文件另存为 apk 在 Android 中(无法安装)

Question

我尝试从服务器下载文件并将其保存在内部存储器中，然后进行安装。 我通过这段代码使用改造下载了它

 Call<ResponseBody> call = apiService.getNewVersion();

    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, 
 Response<ResponseBody> response) {
            if (response.isSuccessful() ) {
                Log.d("1", "server contacted and has file");

                boolean writtenToDisk = 
 writeResponseBodyToDisk(response.body());

                Log.d("2", "file download was a success? " + writtenToDisk);
            } else {
                Log.d("3", "server contact failed");
            }
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            Log.e("4", "error");
        }
    });

我用这段代码保存了它

private boolean writeResponseBodyToDisk(ResponseBody body) {
    try {
        // todo change the file location/name according to your needs
        File futureStudioIconFile = new 
File(context.getExternalFilesDir(null) + File.separator + "app-debug.apk");

        InputStream inputStream = null;
        OutputStream outputStream = null;

        try {
            byte[] fileReader = new byte[4096];

            long fileSize = body.contentLength();
            long fileSizeDownloaded = 0;

            inputStream = body.byteStream();
            outputStream = new FileOutputStream(futureStudioIconFile);

            while (true) {
                int read = inputStream.read(fileReader);

                if (read == -1) {
                    break;
                }

                outputStream.write(fileReader, 0, read);

                fileSizeDownloaded += read;

                Log.d("TAG", "file download: " + fileSizeDownloaded + " of " 
   + fileSize);
            }

            outputStream.flush();

            return true;
        } catch (IOException e) {
            return false;
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }

            if (outputStream != null) {
                outputStream.close();
            }
        }
    } catch (IOException e) {
        return false;
    }
}

它原来的 4.56MB 但在 Android 存储中显示为 6.08MB。 当我打开它安装它显示 version N /A size N/ A 当我尝试安装它时，它显示此 parse problem

你有解决这个问题的想法吗？ 如何去除多余字节？

Answer 1

您应该确保在您的 Web 服务方法中使用 HttpResponseMessage.content，因为正常返回将不是您想要的文件的标准大小:

[HttpGet] 
[Route("api/Depository/DownloadFileFTP")]  // /{pass}
public HttpResponseMessage DownloadFileFTP() //string pass
{  
    HttpResponseMessage result = null;
    string ftphost = "*******";
    string ftpfilepath = "/app-debug.apk";
    byte[] fileData;

    string ftpfullpath = "ftp://" + ftphost + ftpfilepath;

    using (WebClient request = new WebClient())
    {
        request.Credentials = new NetworkCredential("**", "****");
        fileData = request.DownloadData(ftpfullpath);
    }
    byte[] bytes = fileData;               
    result = Request.CreateResponse(HttpStatusCode.OK);
    result.Content = new ByteArrayContent(bytes);
    result.Content.Headers.ContentDisposition = new 
    System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
    result.Content.Headers.ContentDisposition.FileName = "app.apk";
    return result;
}