/// <summary>
/// TreeItem中删除项,返回删除项所在位置
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="instance"></param>
/// <param name="source"></param>
/// <param name="item"></param>
public static int ReMoveItem <T>(this ITreeItemsOption instance, ObservableCollection <T> source, T item) where T : ITreeItem
{
var index = source.IndexOf(item);
source.Remove(item);
Resort(source);
return(index);
}
/// <summary>
/// TreeItem中插入项,并返回插入位置
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="instance"></param>
/// <param name="source"></param>
/// <param name="currentItem"></param>
/// <param name="newitem"></param>
/// <param name="position"></param>
/// <returns></returns>
public static int Insert <T>(this ITreeItemsOption instance, ObservableCollection <T> source, T currentItem, T newitem, Position position) where T : ITreeItem
{
var index = source.IndexOf(currentItem);
var newIndex = position == Position.Above ? index : index + 1;
source.Insert(newIndex, newitem);
Resort(source);
return(newIndex);
}
/// <summary>
/// TreeItem中项上移, 返回当前菜单的新位置索引
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="instance"></param>
/// <param name="source"></param>
/// <param name="item"></param>
public static int MoveUp <T>(this ITreeItemsOption instance, ObservableCollection <T> source, T item) where T : ITreeItem
{
var index = source.IndexOf(item);
if (index > 0)
{
source.Move(index, index - 1);
Resort(source);
return(index - 1);
}
return(-1);
}
/// <summary>
/// TreeItem中增加项
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="instance"></param>
/// <param name="source"></param>
/// <param name="item"></param>
public static void AddItem <T>(this ITreeItemsOption instance, ObservableCollection <T> source, T item) where T : ITreeItem
{
item.SetValue(item, "Sequence", source.Count);
source.Add(item);
}
