我正在使用C# .net core读取用户发送的多个文件的上传数据。在读取最后一个文件后，如何防止用户等待无限时间。
try
{
var cancellationTokenSource = new CancellationTokenSource();
cancellationTokenSource.CancelAfter(1000);
section = await multipartReader.ReadNextSectionAsync(cancellationTokenSource.Token);
}
catch (Exception ex)
{
throw;
}
虽然我已经设置了1秒的cancelationToken，但它变成了无限制的，如果我发送另一个请求，它不会进入下一行。
public static async Task<HttpRequest> FromHttpContextAsync(HttpContext httpContext)
{
bool multipart = false;
HttpRequest retVal = new HttpRequest(httpContext);
var sb = new StringBuilder();
var sr = new StreamReader(httpContext.Stream, Encoding.UTF8);
{
var line1 = await sr.ReadLineAsync();
sb.AppendLine(line1);
var Line1Parts = (line1).Split(' ');
retVal.Methode = Line1Parts[0].ToLower();
retVal.RawUrl = System.Net.WebUtility.UrlDecode(Line1Parts[1]).Replace("&", "&");
var urlPart = retVal.RawUrl.Split('?');
retVal.Url = urlPart[0];
if (urlPart.Length > 1)
{
foreach (var part in urlPart[1].Split(new[] { '&' }, StringSplitOptions.RemoveEmptyEntries))
{
var tmp = part.Split(new[] { '=' }, StringSplitOptions.RemoveEmptyEntries);
try
{
retVal.QueryStrings.Add(tmp[0], tmp[1]);
}
catch (Exception ex)
{
}
}
}
string line = await sr.ReadLineAsync();
sb.AppendLine(line);
int contentLength = 0;
while (!string.IsNullOrEmpty(line))
{
var tmp = line.Split(':');
var key = tmp[0].Trim().ToLower();
retVal.Header.Add(new KeyValuePair<string, string>(tmp[0], tmp[1]));
switch (key)
{
case "cookie":
{
foreach (var part in tmp[1].Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries))
{
var pares = part.Split('=');
if (pares.Length == 2)
{
retVal.Cookies.Add(new KeyValuePair<string, string>(pares[0], pares[1]));
}
}
break;
}
case "content-length":
{
contentLength = int.Parse(tmp[1]);
break;
}
}
line = await sr.ReadLineAsync();
sb.AppendLine(line);
}
if (sb.ToString().Contains("Content-Type: multipart/form-data"))
{
string boundary = FindBoundary(sb.ToString());
MultipartReader multipartReader = new MultipartReader(boundary, httpContext.Stream);
var section = await multipartReader.ReadNextSectionAsync();
while (section != null)
{
// process each image
const int chunkSize = 1024;
var buffer = new byte[chunkSize];
var bytesRead = 0;
var fileName = GetFileName(section.ContentDisposition);
using (var stream = new MemoryStream())
{
do
{
try
{
bytesRead = await section.Body.ReadAsync(buffer, 0, buffer.Length);
}
catch (Exception ex)
{
Console.Write(ex);
}
stream.Write(buffer, 0, bytesRead);
} while (bytesRead > 0);
retVal.Files.Add(new Tuple<string, string, byte[]>("", fileName, stream.ToArray()));
}
try
{
var cancellationTokenSource = new CancellationTokenSource();
cancellationTokenSource.CancelAfter(1000);
section = await multipartReader.ReadNextSectionAsync(cancellationTokenSource.Token);
}
catch (Exception ex)
{
throw;
}
}
foreach (var file in retVal.Files)
{
File.WriteAllBytes("d:\\" + file.Item2, file.Item3);
}
}
HttpContext是此项目的内联类，以下是HttpContext的源代码：
public class HttpContext
{
public HttpRequest Request { get; private set; }
public HttpResponse Response { get; private set; }
public Stream Stream { private set; get; }
private HttpContext(Stream networkStream)
{
Stream = networkStream;
}
public async static Task<HttpContext> FromHttpContextAsync(Stream networkStream)
{
var retVal = new HttpContext(networkStream);
retVal.Request = await HttpRequest.FromHttpContextAsync(retVal);
retVal.Response = HttpResponse.FromHttpContext(retVal);
return retVal;
}
}