Named attribute argument expected
Unnamed attribute arguments must appear before the named arguments.
The following sample generates CS1016:
using System; [attribute(AllowOn = AttributeTargets.Classes)] public class HelpAttribute { public HelpAttribute(string url) { // url is a positional parameter m_url = url; } public string Topic = null; // Topic is a named parameter private string m_url = null; public string Url { get {return m_url;} } } [HelpAttribute("http://intranet/inhouse")] class Class1 { } [HelpAttribute(Topic="Samples", "http://intranet/inhouse")] // CS1016 // try the following line instead // [HelpAttribute("http://intranet/inhouse", Topic="Samples")] class Class2 { } public class MainClass { public static void Main () { } }