Returning 'Allow' Entity Header with HTTPResponseMessage in WCF Web API - wcf

Question

I'm trying to return the 'Allow' entity header within the response message and I keep getting the following message:
{"The header cannot be added. Make sure to add request headers to HttpRequestMessage, response headers to HttpResponseMessage, and content headers to HttpContent objects."}
Here's the code snippet:
[WebInvoke(UriTemplate = "{id}", Method = "DELETE")]
public HttpResponseMessage<Order> DeleteOrder(int id)
{
HttpResponseMessage<Order> response = null;
try
{
if (id <= 0)
{
response = new HttpResponseMessage<Order>(HttpStatusCode.BadRequest);
}
else
{
// For brevity, I'm assuming that order - 123456 was already served and logged. Hence it cannot
// be deleted. Order 12345, however, can be deleted.
// Note: The code doesn't actual delete anything. This is just a demonstration of
// the DELETE verb
if (id == 12345)
{
return new HttpResponseMessage<Order>(HttpStatusCode.NoContent);
}
if (id == 123456)
{
response = new HttpResponseMessage<Order>(HttpStatusCode.MethodNotAllowed);
response.Headers.AddWithoutValidation("Allow", "PUT");
}
// return '404 - Not Found' status code
response = new HttpResponseMessage<Order>(HttpStatusCode.NotFound);
}
return response;
}
catch (Exception ex)
{
return response = new HttpResponseMessage<Order>(HttpStatusCode.InternalServerError);
}
}
Any advice would be very helpful.
Thanks,
dorman

Answer 1

Try response.Content.Headers instead.