private int AddInternal(object item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
int index = -1;
if (!owner.sorted)
{
InnerArray.Add(item);
}
else
{
if (Count > 0)
{
index = InnerArray.BinarySearch(item);
if (index < 0)
{
index = ~index; // getting the index of the first element that is larger than the search value
//this index will be used for insert
}
}
else
{
index = 0;
}
Debug.Assert(index >= 0 && index <= Count, "Wrong index for insert");
InnerArray.Insert(index, item);
}
bool successful = false;
try
{
if (owner.sorted)
{
if (owner.IsHandleCreated)
{
owner.NativeInsert(index, item);
owner.UpdateMaxItemWidth(item, false);
if (owner.selectedItems != null)
{
// Sorting may throw the LB contents and the selectedItem array out of synch.
owner.selectedItems.Dirty();
}
}
}
else
{
index = Count - 1;
if (owner.IsHandleCreated)
{
owner.NativeAdd(item);
owner.UpdateMaxItemWidth(item, false);
}
}
successful = true;
}
finally
{
if (!successful)
{
InnerArray.Remove(item);
}
}
return(index);
}