Question

我想从GET HTTP REQUEST响应中下载文件。要下载流，我使用HttpClient就像这个示例：

using System.Net.Http;
using System.Net.Http.Headers;
using ModernHttpClient;

var exClient = new HttpClient(new NativeMessageHandler());
var request = new HttpRequestMessage(new HttpMethod(method), "https://speed.hetzner.de/10GB.bin");
HttpResponseMessage response = await exClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
var contentStream = await response.Content.ReadAsStreamAsync();

我想将文件保存到磁盘，所以我使用System.IO。

首先，我使用以下代码：

using IOFile = System.IO.File;

Stream file = IOFile.Open(path, FileMode.Create);
contentStream.CopyTo(file);
file.close;

但是我也想获取有关下载进度的信息，所以我切换到以下代码：

using IOFile = System.IO.File;

Stream file = IOFile.Open(path, FileMode.Create);

var buffer = new byte[81920];
int received = 0;
int read = 0;

while ((read = await contentStream.ReadAsync(buffer, 0, buffer.Length)) > 0)
{
    file.Write(buffer, 0, read);

    received += read;

    //progressCallback?.Invoke(received);
}

file.Close();

我的问题是下载时间变得比使用CopyTo方法的时间长两倍以上（大约30Mbit / s，而CopyTo约为90）。

什么解释了这种差异？我该如何接近CopyTo的表现？

C＃下载文件流性能问题

0 个答案: