Catches otherwise uncaught TaskCanceledException objects. Useful with WebApi and async await programming. We get a handle to the buffer so that we can replay the reading of the buffer for logging purposes later.

Global.asax.cs

public class WebApiApplication : System.Web.HttpApplication
{
	protected void Application_Start()
	{
		//...
		GlobalConfiguration.Configuration.MessageHandlers.Add(new TaskCanceledExceptionHandler());
	}
}

TaskCanceledExceptionHandler.cs

using System.IO;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

namespace MvcApplication1.App_Start
{
	public class TaskCanceledExceptionHandler : DelegatingHandler
	{
		protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
		{
			using (var buffer = await request.Content.ReadAsStreamAsync())
			{ 
				try
				{
					return await base.SendAsync(request, cancellationToken);
				}
				catch (TaskCanceledException e)
				{
					string content = "";
					if (buffer.CanSeek && buffer.CanRead)
					{
						buffer.Seek(0, SeekOrigin.Begin);
						using (var reader = new StreamReader(buffer))
						{
							content = reader.ReadToEnd();
						}
					}
					return request.CreateErrorResponse(HttpStatusCode.InternalServerError, request.ToString() + ", " + "Content: " + content, e);
				}
			}
		}
	}
}