Build a web service in ASP.NET / C# / Linq-to-SQL

Question

I'm trying to build a simple web service which return a list of shows from a database. The web service has the following code to get its data:

private BLLoptredens BLLoptredens = new BLLoptredens();

[WebMethod]
public Array getVoorstellingenByArtiest(string p_artiest)
{
    return BLLoptredens.selectByArtistName(p_artiest).ToArray() ;
}

The data comes from the BLL, which just passes data from the DAL like so:

public IList<Optreden> selectByArtistName(string p_artiest)
{
   var query = (from o in dc.Optredens
                where o.artiest.Contains(p_artiest)
                select o);
   return query.ToList();
}

This crashes with the following error:

You must implement a default accessor on System.Array because it inherits from ICollection

Can something help me on my way with this?

do not return an Array from the webmethod.you can return an array like Optreden[] if Optreden is serializable instead. — Davide Piras
– Davide Piras, Commented Nov 24, 2011 at 13:28
I get an iList<Optreden> from my DAL. How can I convert that to Optreden[]? — Jorre
– Jorre, Commented Nov 24, 2011 at 13:29

Alexander Galkin · Accepted Answer · 2011-11-24 13:29:38Z

1

Is there any particular need to give back an interface instead of a full-fledged generic class?

Try changingIList<Optreden> to List<Optreden> -- that should do it.

answered Nov 24, 2011 at 13:29

Alexander Galkin

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2 Comments

Jorre Over a year ago

that works! Thanks a lot. Is there a reason why I should still use iList instead of List in my code? Otherwise List seems like a more flexible solution?

Alexander Galkin Over a year ago

List<> gives you the full class, where IList<> allows you to give back something that is basically not a List<>, but implements a similar behavior. Since you have a LIst<> already in your method there is no advantage of giving back just an interface.

samn · Accepted Answer · 2011-11-24 13:27:51Z

0

try public List instead of public IList

answered Nov 24, 2011 at 13:27

samn

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Comments

John Gathogo · Accepted Answer · 2011-11-24 13:31:11Z

0

public Optreden[] getVoorstellingenByArtiest(string p_artiest)
{
    return BLLoptredens.selectByArtistName(p_artiest).ToArray() ;
}

Note the Optreden[]. And I hope the Optreden is a DataContract with serializable members decorated with DataMember attribute

answered Nov 24, 2011 at 13:31

John Gathogo

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