Question

I have a WCF service that needs to expose a custom collection to it’s clients. I wondered what would be the best way to expose this object to my clients?

Object Code:

  public class ListBoxDataCollection : System.Collections.CollectionBase
{
    public ListBoxDataCollection()
    {
    }

    public ListBoxData this[int index] 
    {
        get { return (ListBoxData)this.List[index]; }

        set { this.List[index] = value; }
    }

    public int IndexOf( ListBoxData item )
    {
        return base.List.IndexOf(item);
    }

    public int Add( ListBoxData item )
    {
        return this.List.Add(item);
    }

    public void Remove( ListBoxData item )
    {
        this.InnerList.Remove(item);  
    }

    public void CopyTo( Array array, int index )
    {
        this.List.CopyTo(array, index);
    }

    public void AddRange( ListBoxDataCollection collection )
    {
        for (int i = 0; i < collection.Count; i++)
        {
            this.List.Add(collection[i]);
        }
    }

    public void AddRange( ListBoxData[] data )
    {
        this.AddRange(data);
    }

    public bool Contains( ListBoxData item )
    {
       return this.List.Contains(item);
    }

    public void Insert( int index, ListBoxData item )
    {
        this.List.Insert(index, item);
    }
}

Answer 1

Are you on .NET 3.5 or up? In that case, I would recommend List<ListBoxData> which seems like the easiest way to go. WCF was no trouble at all with generic lists – worst case it’ll model them as an array of ListBoxData on the client.

If you own both ends of the communication, you could put the data contracts (and service contracts) into a shared assembly and use it on both ends, thus getting around this problem – in that case, you could use List<ListBoxData> on both ends of the communication.

Marc