Get a Jump on Navigation in Windows Phone with the LongListSelector: Listing 1.

The Group <T> class

public class Group <T> : IEnumerable <T> where T : class
{
  public string KeyName { get; set; }
  public IList <T> Items { get; set; }

  public Group(string name, IEnumerable <T> items)
  {
    KeyName = name;
    if (items == null)
    {
      items = new T[] { };
    }
    Items = new List <T>(items);
  }

  public bool HasItems
  {
    get { return this.FirstOrDefault() != null; }
  }

  public Visibility HasItemsVisibility
  {
    get { return HasItems ? Visibility.Visible : Visibility.Collapsed; }
  }

  public Visibility HasNoItemsVisibility
  {
    get { return HasItems ? Visibility.Collapsed : Visibility.Visible; }
  }

  public IEnumerator <T> GetEnumerator()
  {
    return Items.GetEnumerator();
  }

  IEnumerator IEnumerable.GetEnumerator()
  {
    return Items.GetEnumerator();
  }
}

About the Author

Nick Randolph runs Built to Roam, a consulting company that specializes in training, mentoring and assisting other companies build mobile applications. With a heritage in rich client applications for both the desktop and a variety of mobile platforms, Nick currently presents, writes and educates on the Windows Phone platform.