Workaround to get object from body with mono 4.2.x

StreamExtenion

// workaround class
public static class StreamExtension
	{
		private static MediaTypeFormatterCollection _defaultMediaTypeFormatterCollection = null;

		// Using the JsonMediaTypeFormatter for the first time is rather expensive (due to reflection cost
		// when creating the default contract resolver). Hence we new up a static collection, such
		// that the second call is much faster.
		private static MediaTypeFormatterCollection DefaultMediaTypeFormatterCollection
		{
			get
			{
				if (_defaultMediaTypeFormatterCollection == null)
				{
					_defaultMediaTypeFormatterCollection = new MediaTypeFormatterCollection();
				}

				return _defaultMediaTypeFormatterCollection;
			}
		}

		public static T ReadAs<T>(this System.Web.HttpRequest request)
		{
			return request.ReadAs<T>(DefaultMediaTypeFormatterCollection);
		}

		public static T ReadAs<T>(this System.Web.HttpRequest request, IEnumerable<MediaTypeFormatter> formatters)
		{
			return ReadAs<T>(request, typeof(T), formatters, null);
		}

		private static T ReadAs<T>(System.Web.HttpRequest request , Type type, IEnumerable<MediaTypeFormatter> formatters,
			IFormatterLogger formatterLogger)
		{
			if (request.InputStream == null)
			{
				throw new ArgumentNullException("content");
			}
			if (type == null)
			{
				throw new ArgumentNullException("type");
			}
			if (formatters == null)
			{
				throw new ArgumentNullException("formatters");
			}
			// Default to "application/octet-stream" if there is no content-type in accordance with section 7.2.1 of the HTTP spec
			MediaTypeHeaderValue mediaType = null;
			try {
				mediaType = new MediaTypeHeaderValue(request.ContentType);
			}
			catch {
				mediaType = new MediaTypeHeaderValue ("application/octet-stream");
			}

//			ObjectContent objectContent = new ObjectContent(typeof T,"test",null
//			if (objectContent != null && objectContent.Value != null && type.IsAssignableFrom(objectContent.Value.GetType()))
//			{
//				return Task.FromResult((T)objectContent.Value);
//			}



			MediaTypeFormatter formatter = new MediaTypeFormatterCollection(formatters).FindReader(type, mediaType);

			if (formatter == null)
			{
				if (request.ContentLength == 0)
					return default(T);

				throw new UnsupportedMediaTypeException(
					string.Format("NoReadSerializerAvailable {0} {1}", type.Name, mediaType.MediaType),
					mediaType);
			}

			return ReadAsCore<T>(request, type, formatterLogger, formatter);
		}

		private static T ReadAsCore<T>(System.Web.HttpRequest request , Type type, IFormatterLogger formatterLogger,
			MediaTypeFormatter formatter)
		{
			
			Stream stream = request.InputStream;

			object result = formatter.ReadFromStreamAsync(type, stream, null, formatterLogger).Result;
			return (T)result;
		}
	}

Usage:

Original line looks like
public virtual IHttpActionResult Post([FromBody] T value) { ... }

with the workaround
public virtual IHttpActionResult Post() { T value = HttpContext.Current.Request.ReadAs<T> (); ... }