C# how to get the filled parameter names from request maching with the action parameters excluding default asp.net and http headers etc..

LogonAuthorize.cs

 public class LogonAuthorize : AuthorizeAttribute
    {
        var parameters = context.ActionDescriptor.GetParameters();
        var contextParams = parameters.Select(s => s.ParameterName.ToLowerInvariant()).
                              Intersect(context.RequestContext.HttpContext.Request.Params.AllKeys.
                                  Select(x=>!string.IsNullOrEmpty(context.RequestContext.HttpContext.Request.Params[x]) 
                                  ? x.ToLowerInvariant() : null));