protected override void OnItemAdding(ColumnBase item)
{
base.OnItemAdding(item);
Debug.Assert(item != null);
if (item.IsMainColumn)
{
m_nextMainColumn = item;
}
item.AttachToContainingCollection(this);
item.PropertyChanged += new PropertyChangedEventHandler(this.OnColumnPropertyChanged);
item.RealizedContainersRequested += new RealizedContainersRequestedEventHandler(this.OnColumnRealizedContainersRequested);
item.ActualWidthChanged += new ColumnActualWidthChangedEventHandler(this.OnColumnActualWidthChanged);
item.DistinctValuesRequested += new DistinctValuesRequestedEventHandler(this.OnColumnDistinctValuesRequested);
}
