winforms - DataGridView sort and e.g. BindingList<T> in .NET

Question

I'm using a BindingList<T> in my Windows Forms that contains a list of "IComparable<Contact>" Contact-objects. Now I'd like the user to be able to sort by any column displayed in the grid.

There is a way described on MSDN online which shows how to implement a custom collection based on BindingList<T> which allows sorting. But isn't there a Sort-event or something that could be caught in the DataGridView (or, even nicer, on the BindingSource) to sort the underlying collection using custom code?

I don't really like the way described by MSDN. The other way I could easily apply a LINQ query to the collection.

Answer 1

I googled and tried on my own some more time...

There is no built-in way in .NET so far. You have to implement a custom class based on BindingList<T>. One way is described in Custom Data Binding, Part 2 (MSDN). I finally produces a different implementation of the ApplySortCore-method to provide an implementation which is not project-dependent.

protected override void ApplySortCore(PropertyDescriptor property, ListSortDirection direction)
{
    List<T> itemsList = (List<T>)this.Items;
    if(property.PropertyType.GetInterface("IComparable") != null)
    {
        itemsList.Sort(new Comparison<T>(delegate(T x, T y)
        {
            // Compare x to y if x is not null. If x is, but y isn't, we compare y
            // to x and reverse the result. If both are null, they're equal.
            if(property.GetValue(x) != null)
                return ((IComparable)property.GetValue(x)).CompareTo(property.GetValue(y)) * (direction == ListSortDirection.Descending ? -1 : 1);
            else if(property.GetValue(y) != null)
                return ((IComparable)property.GetValue(y)).CompareTo(property.GetValue(x)) * (direction == ListSortDirection.Descending ? 1 : -1);
            else
                return 0;
        }));
    }

    isSorted = true;
    sortProperty = property;
    sortDirection = direction;
}

Using this one, you can sort by any member that implements IComparable.