public virtual async Task <ContentType> DetectContentTypeAsync(Uri url, ContentKind contentKind, CancellationToken cancellationToken, IWebReader parent = null)
{
ContentType contentType = EnumerableExtensions.SingleOrDefaultSafe <ContentType>((IEnumerable <ContentType>) this._contentTypeDetector.GetContentType(url, (string)null, (string)null));
ContentType contentType1;
if ((ContentType)null != contentType)
{
Debug.WriteLine("HttpClientWebReaderManager.DetectContentTypeAsync() url ext \"{0}\" type {1}", (object)url, (object)contentType);
contentType1 = contentType;
}
else
{
Uri referrer = HttpClientWebReaderManager.GetReferrer(parent);
using (HttpClient client = this._httpClientFactory.CreateClient(url, referrer, ContentKind.Unknown, (ContentType)null))
{
try
{
using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Head, url))
{
using (HttpResponseMessage httpResponseMessage = await HttpClientExtensions.SendAsync(client, request, HttpCompletionOption.ResponseHeadersRead, cancellationToken, referrer, new long?(), new long?()).ConfigureAwait(false))
{
if (httpResponseMessage.IsSuccessStatusCode)
{
contentType = EnumerableExtensions.SingleOrDefaultSafe <ContentType>((IEnumerable <ContentType>)HttpClientContentTypeDetectorExtensions.GetContentType(this._contentTypeDetector, request.RequestUri, httpResponseMessage.Content.Headers, HttpContentExtensions.FileName(httpResponseMessage.Content)));
if ((ContentType)null != contentType)
{
Debug.WriteLine("HttpClientWebReaderManager.DetectContentTypeAsync() url HEAD \"{0}\" type {1}", (object)url, (object)contentType);
contentType1 = contentType;
goto label_49;
}
}
}
}
}
catch (HttpRequestException ex)
{
}
try
{
using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, url))
{
using (HttpResponseMessage httpResponseMessage = await HttpClientExtensions.SendAsync(client, request, HttpCompletionOption.ResponseHeadersRead, cancellationToken, referrer, new long?(0L), new long?(0L)).ConfigureAwait(false))
{
if (httpResponseMessage.IsSuccessStatusCode)
{
contentType = EnumerableExtensions.SingleOrDefaultSafe <ContentType>((IEnumerable <ContentType>)HttpClientContentTypeDetectorExtensions.GetContentType(this._contentTypeDetector, request.RequestUri, httpResponseMessage.Content.Headers, HttpContentExtensions.FileName(httpResponseMessage.Content)));
if ((ContentType)null != contentType)
{
Debug.WriteLine("HttpClientWebReaderManager.DetectContentTypeAsync() url range GET \"{0}\" type {1}", (object)url, (object)contentType);
contentType1 = contentType;
goto label_49;
}
}
}
}
}
catch (HttpRequestException ex)
{
}
try
{
using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, url))
{
using (HttpResponseMessage httpResponseMessage = await HttpClientExtensions.SendAsync(client, request, HttpCompletionOption.ResponseHeadersRead, cancellationToken, referrer, new long?(), new long?()).ConfigureAwait(false))
{
if (httpResponseMessage.IsSuccessStatusCode)
{
contentType = EnumerableExtensions.SingleOrDefaultSafe <ContentType>((IEnumerable <ContentType>)HttpClientContentTypeDetectorExtensions.GetContentType(this._contentTypeDetector, request.RequestUri, httpResponseMessage.Content.Headers, HttpContentExtensions.FileName(httpResponseMessage.Content)));
if ((ContentType)null != contentType)
{
Debug.WriteLine("HttpClientWebReaderManager.DetectContentTypeAsync() url GET \"{0}\" type {1}", (object)url, (object)contentType);
contentType1 = contentType;
goto label_49;
}
}
}
}
}
catch (HttpRequestException ex)
{
}
}
Debug.WriteLine("HttpClientWebReaderManager.DetectContentTypeAsync() url header \"{0}\" unknown type", (object)url);
contentType1 = (ContentType)null;
}
label_49:
return(contentType1);
}