I discovered the TypedReflector
on Daniel Cazzulino’s Blog. In essence, a simplified version of the code looks like:

public static class Reflector
{
 public static PropertyInfo GetProperty<t, TRet>(Expression<func<t, TRet>> expression)
 {
  return GetMemberInfo(expression) as PropertyInfo;
 }

 public static FieldInfo GetField<t, TRet>(Expression<func<t, TRet>> expression)
 {
  return GetMemberInfo(expression) as FieldInfo;
 }

 public static MethodInfo GetMethod<t, TRet>(Expression<func<t, TRet>> expression)
 {
  return GetMemberInfo(expression) as MethodInfo;
 }

 public static MemberInfo GetMemberInfo(Expression memberInfoExpression)
 {
  Expression lambdaBodyExpression = ((LambdaExpression)memberInfoExpression).Body;
  switch (lambdaBodyExpression.NodeType)
  {
   case ExpressionType.MemberAccess:
    return ((MemberExpression)lambdaBodyExpression).Member;
   case ExpressionType.Call:
    return ((MethodCallExpression)lambdaBodyExpression).Method;
   default:
    throw new ArgumentException("Unsupported NodeType");
  }
 }
}

This class allows me to write the following:

PropertyInfo namePropertyInfo = Reflector.GetProperty<person, string>(p => p.Surname);

Not only can i be sure that the lambda (and thus the namePropertyInfo.Invoke) will always return a string, i can also use it to avoid ‘hardcoded’ propertynames:

//const string SurnameProperty = "Surname";
//comboBox1.DisplayMember = SurnameProperty;
comboBox1.DisplayMember = Reflector.GetProperty<person, string>(p => p.Surname).Name;

A while ago i posted some code that demonstrated how to find the members of an AD group. If you’re using the brandnew .Net 3.5 framework you can take advantage of the System.DirectoryServices.AccountManagement library which is an abstraction for AD (DS, LDS) and SAM accounts. Using this new library my method can be simplified:

private static IEnumerable<string> FindUsernames(string groupname)
{
 PrincipalContext principalContext = new PrincipalContext(ContextType.Domain, "mydomain");
 GroupPrincipal groupPrincipal = GroupPrincipal.FindByIdentity(principalContext, groupname);

 foreach (Principal principal in groupPrincipal.Members)
 {
  yield return principal.DistinguishedName;
 }
}

If you’re looking for more information i would recommend that you read Managing Directory Security Principals in the .NET Framework 3.5.

A while ago i bought Media Centerkit for an euro or two. I wouldn’t recommend the product because it comes with crappy software. Anyway, i was only interested in playing with the hardware (RF Remote and USB Receiver) so i downloaded the ActiveHome Professional SDK. Once you install this you can add a reference to “ActiveHomeScript 1.0 Type Library” under the COM tab in Visual Studio. I wrote a little library so that i can consume the ActiveHomeClass.RecvAction in a Type-safe way:

Here is some sample code that demonstrates how you can use the Notifier to receive Notifications:

// register our eventhandler and tell the notifier to start raising events
Notifier.Instance.NotificationReceived += this.Instance_NotificationReceived;
Notifier.Instance.Enable();

private void Instance_NotificationReceived(object sender, NotificationReceivedEventArgs e)
{
 // for more complex logic i would recommend that you apply a Filter pattern...
 RadioFrequencyNotification rfNotification = e.Notification as RadioFrequencyNotification;
 if (rfNotification.IsKeyPressed)
 {
  if (rfNotification.Command == RadioFrequencyCommand.Menu)
  {
   this.RaiseToolStripMenuItemClicked(this.MenuClicked, EventArgs.Empty);
  }
 }
}

As always feel free to download the library and sample application: ActiveHome.zip

Because i always seem to forget about the syntax of LDAP Search Filters (RFC 2254: The String Representation of LDAP Search Filters and Creating a Query Filter) i’m going to post a basic demo of DirectorySearcher that returns the members that are part of a given AD group:

private static void Main(string[] args)
{
 foreach (string member in FindUsernames("?CWBE-PS-.NetDev"))
 {
  Console.WriteLine(member);
 }

 Console.Write("{0}Press any key to continue...", Environment.NewLine);
 Console.ReadKey();
}

private static IEnumerable<string> FindUsernames(string groupname)
{
 string filter = "(&(&(objectCategory=Group)(objectClass=Group))(name={0}))";
 filter = string.Format(filter, groupname);

 DirectoryEntry directoryEntry = new DirectoryEntry();
 DirectorySearcher searcher = new DirectorySearcher(directoryEntry);
 searcher.SearchScope = SearchScope.Subtree;
 searcher.Filter = filter;

 DirectoryEntry groupEntry = searcher.FindOne().GetDirectoryEntry();
 PropertyValueCollection members = (PropertyValueCollection)groupEntry.Properties["member"];
 return ConvertAll<object, string>((object[])members.Value);
}

private static IEnumerable<to> ConvertAll<from, To>(IEnumerable<from> elements)
{
 Type toType = typeof(To);

 foreach (From element in elements)
 {
  yield return (To)Convert.ChangeType(element, toType);
 }
}