/// <summary>
/// 'Cancel' button is clicked
/// </summary>
public void CancelEdit()
{
Restore(cache);
cache = null;
}
/// <summary>
/// 'Edit' button is clicked
/// Due to binding, all UI changed will be mapped to the object, so we need make a copy of object before edit in case user wants to cancel the editing
/// </summary>
public void BeginEdit()
{
cache = new ItemView(this);
}