private void _Cells_ItemsAdded(object sender, NotifyCollectionChangedEventArgs e)
{
if (sender is CellCollection)
{
foreach (Cell cell in e.NewItems)
{
if (cell.Row > Rows.Count)
{
Rows.Create(cell.Row - Rows.Count);
}
if (cell.Column > Columns.Count)
{
Columns.Create(cell.Column - Columns.Count);
}
}
}
}
