C#

BOOL CALLBACK EnumProc(LPCTSTR s);
BOOL EnumSomething(EnumProc proc);

public delegate bool EnumProc(string s);
// In some class...
public bool EnumSomething(EnumProc proc);

bool val = EnumSomething(new EnumProc(MyEnumProc));
//...
private bool MyEnumProc(string s)
{
  Console.WriteLine(s);
}

EuroCPian Spring 2004 Get Together[^]

public class Test
{
  [DllImport("uxtheme.dll")]
  private static extern bool IsAppThemed();
 
  public bool Themed
  {
    get
    {
      // Just in case, we'll catch exceptions anyway!
      try
      {
        Version v = OSFeature.Feature.GetVersionPresent(OSFeature.Themes);
        return v != null;
      }
      catch { return false; }
    }
  }
}

public class MyLabel : Label
{
  public override string Text
  {
    get { return base.Text; }
    set { base.Text = string.Concat("Prefix: ", value); }
  }
}