How to use System.Net.HttpRequestHeader enum with an ASP.NET request? - asp.net

Question

In WCF (System.Net.WebHeaderCollection) a header value can be retreived using either the System.Net.HttpRequestHeader enum or a header string:
WebOperationContext.Current.IncomingRequest.Headers[httpRequestHeaderEnum]
// or
WebOperationContext.Current.IncomingRequest.Headers.Get(rawHeaderString)
But in ASP.NET, the headers are in a NameValueCollection which only accepts a header string:
HttpContext.Current.Request.Headers[rawHeaderString]
In order to use the Enum's for ASP.NET, where is the map from enum System.Net.HttpRequestHeader to its header string?

Answer 1

How about writing a mapping method? For reference:
HttpRequestHeader enumeration
You could just make a mapping table, or Using code swiped from Binary Worrier's post, you could do something like this:
public static string TranslateToHttpHeaderName(HttpRequestHeader enumToTranslate)
{
const string httpHeaderNameSeparator = "-";
string enumName = enumToTranslate.ToString();
var stringBuilder = new StringBuilder();
// skip first letter
stringBuilder.Append(enumName[0]);
for (int i = 1; i < enumName.Length; i++)
{
if (char.IsUpper(enumName[i])) stringBuilder.Append(httpHeaderNameSeparator);
stringBuilder.Append(enumName[i]);
}
// Cover special case for 2 character enum name "Te" to "TE" header case.
string headerName = stringBuilder.ToString();
if (headerName.Length == 2) headerName = headerName.ToUpper();
return headerName;
}

Answer 2

You can use a default implementation, using a WebHeaderCollection
private static readonly ConcurrentDictionary<HttpRequestHeader, string> ToStringKeyCache = new ConcurrentDictionary<HttpRequestHeader, string>();
public static string ToStringKey(this HttpRequestHeader enumToEvaluate)
{
var str = ToStringKeyCache.GetOrAdd(enumToEvaluate, header =>
{
var nm = new WebHeaderCollection();
nm.Set(header, "X");
return nm.AllKeys.Single();
});
return str;
}

Answer 3

Unless I completely misunderstood your question:
Import the System.Net namespace: using System.Net;
e.g. WebForms:
using System.Net
protected void Page_Load(object sender, EventArgs e)
{
//Single - e.g. Connection
FooLabel.Text = Request.Headers[HttpRequestHeader.Connection.ToString()] + "<hr />";
//Go through all
foreach (var en in Enum.GetNames(typeof(HttpRequestHeader)))
{
FooLabel.Text += en + " : " + Request.Headers[en] + "<br />";
}
}
Hth...