Sort and BinarySearch in IList<T>

rick.machado · **Joined:** Fri Mar 14, 2008 2:32 pm **Posts:** 3

Hi everybody

I'm switching my application to NHibernate

I'm trying to change all List<T> to IList<T>, but i lost the sort method : sort(IComparer<T>), and the method BinarySearch(T, IComparer<T>)

Otherwise, i sow another methods that can suply this lost. But i dont know what way to choose. Can anyone help me?

Or maybe, could I use a sort method for the IList<T> using the class IComparer<T> in NHibernate?

Any Ideas?

wolli · **Posted:** Fri Mar 14, 2008 3:44 pm

We're using a wrapper for hibernates list implementation which implements the usual interfaces like IList, ICollection, ... most of the time I'm passing the calls through to the inner list. Additionally the wrapper supplies some functions like sorting. Other possibility is implementing your own ILists for hibernate (there're some interfaces from hibernate to implement), but I think that's more work to do.

rick.machado · **Joined:** Fri Mar 14, 2008 2:32 pm **Posts:** 3

Could you show my a exemple using sorting ?

Thanks for the help

wolli · **Posted:** Fri Mar 14, 2008 4:51 pm

Code:

 public abstract class ListBase<T> : 
               IList<T>, 
               IEnumerable<T>, 
               IRaiseItemChangedEvents 
               where T : class, INotifyPropertyChanged
    {

        /// <summary>
        /// Hibernates IList
        /// </summary>
        protected IList<T> items;       
...
        public virtual void Sort( Comparison<T> comparer )
        {
            // Iteration durch die Liste
            for ( int i = 0; i < items.Count - 1; i++ )
            {
                for ( int j = i + 1; j < items.Count; j++ )
                {
                    if ( comparer( items[i], items[j] ) > 0 )
                    {
                        T temp = items[i];
                        items[i] = items[j];
                        items[j] = temp;
                    }
                }
            }

            // raise Reset Event 
            RaiseListChangedEvent( new ListChangedEventArgs( ListChangedType.Reset, -1 ) );
        }
...
}

and the mapping for this list in a class

Code:

    <component name="PartnerItems" class="PartnerList">
      <bag name="Items" table="sx.bus_partner" lazy="false" order-by="orderby asc" cascade="all-delete-orphan">
        <key column="containeruid"/>
        <one-to-many class="Partner"/>
      </bag>
    </component>

where Partnerlist is derived from ListBase<Partner>.

aedenj · **Joined:** Thu Dec 14, 2006 7:08 pm **Posts:** 11

Alternatively, investigate ArrayList.Adapter(). It wraps the underlying storage of IList and provides sorting and searching.

For example,

IList<Example> ExampleList = new List<Example>();

ArrayList.Adapter(ExampleList as IList).Sort(ExampleComparer);

I hope that helps.

Cheers,
Aeden

aedenj · **Joined:** Thu Dec 14, 2006 7:08 pm **Posts:** 11

Alternatively, investigate ArrayList.Adapter(). It wraps the underlying storage of IList and provides sorting and searching.

For example,

IList<Example> ExampleList = new List<Example>();

ArrayList.Adapter(ExampleList as IList).Sort(ExampleComparer);

From my understanding .NET's quicksort algorithm gets used. I hope that helps.

Cheers,
Aeden