In a previous post, Justin and I were discussing the idea of having a generic object comparer. Well this morning I busted one out. Here it is. Enjoy!

public class GenericClassComparer : IComparer
{
  public GenericClassComparer( System.Type objectType, string propertyName )
  {
    LoadPropertyInfo( objectType, propertyName );
  }

  private void LoadPropertyInfo( System.Type objectType, string propertyName )
  {
    MemberInfo[] members = objectType.GetMember( propertyName, 
      MemberTypes.Property, BindingFlags.Public | BindingFlags.Instance );

    if( members.Length > 0 )
    {
      MemberInfo member = members[0];
      if( member is PropertyInfo )
        _pi = (PropertyInfo) member;
    }
  }

  public int Compare( object o1, object o2 )
  {
    if( _pi == null )
      throw new ArgumentException("Invalid property name specified.");

    object val1 = _pi.GetValue( o1, null );
    object val2 = _pi.GetValue( o2, null );

    if( val1 is IComparable )
    {
      IComparable c1 = (IComparable) val1;
      IComparable c2 = (IComparable) val2;
      return c1.CompareTo(c2);
    }

    return 0;
  }

  private PropertyInfo _pi = null;
}