/// <summary> /// GroupItemのヘッダを固定表示するBehavior /// </summary> public class GroupHeaderFrozenBehavior : Behavior<ItemsControl> { private static readonly Dictionary<GroupItem, WeakReference<HeaderAdorner>> _CurrentGroupItem = new Dictionary<GroupItem, WeakReference<HeaderAdorner>>(); #region HeaderTemplate依存関係プロパティ public DataTemplate HeaderTemplate { get { return (DataTemplate)GetValue(HeaderTempla