public GroupCollection <TItem, TGroup> AddItem(TItem item)
{
EnsureItems();
var add = new GroupCollectionItem <TItem>()
{
Item = item,
Index = _items.Count,
GroupIndex = -1
};
_items.Add(add);
return(this);
}
public GroupCollection <TItem, TGroup> AddItem(TItem item, int groupIndex)
{
EnsureItems();
EnsureGroups();
if (groupIndex < 0 || groupIndex >= _groups.Count)
{
throw new ArgumentException(string.Format("invalid index {0}", groupIndex));
}
var add = new GroupCollectionItem <TItem>()
{
Item = item,
GroupIndex = groupIndex
};
var first = _items.FirstOrDefault(e => e.GroupIndex > groupIndex || e.GroupIndex == -1);
if (first == null)
{
add.Index = _items.Count;
_items.Add(add);
}
else
{
add.Index = first.Index;
foreach (var i in _items.Where(e => e.Index >= add.Index))
{
i.Index++;
}
_items.Insert(add.Index, add);
}
var group = _groups[groupIndex];
group.ItemCount++;
return(this);
}
