Using GetFields() to return a comma-separated list of fields on an object.

gistfile1.cs

public string GetFieldNames(Type type)
{
   return string.Join(",", GetFields(type).Select(t => t.Name).ToArray());
}

public static IEnumerable<FieldInfo> GetFields(Type currentType)
{
   foreach (FieldInfo fi in currentType.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly))
   {
      if (!(typeof(Delegate)).IsAssignableFrom(fi.FieldType)) yield return fi;
   }
}

// An example object
public class SampleObject
{
   // Note the use of fields instead of properties.
   public string Foo;
   public string Bar;
   public string Baz;
}