Question

i use entity framework and have the below code:

public class AdvPackageInfo
{
    private int PackageId;
    private string Caption;
    private int Duration;
    private int Count;
    private bool Enable;
    private float Price;
}


 AdvertismentAgancyEntities enn = new AdvertismentAgancyEntities();

 List<AdvPackageInfo> lst = (from s in enn.Tbl_AdvPackage select new AdvPackageInfo { }).ToList();

    repeater1.DataSource = lst;
    repeater1.DataBind();

but it works just 1 time and when my page load for the second time it fails in execution and raise NullReferenceException…!!

according to this pag :
http://connect.microsoft.com/VisualStudio/feedback/details/663200/linq-to-entities-throws-nullreferenceexception-when-the-output-attribute-set-is-empty
it’s dot net framework problem.

i try this code too :

var q = (from s in enn.AdvPackage select s).toList();

but it doesn’t work either.

is there any better way to make a linq select to a list????

Answer 1

Instead of this line:

List<AdvPackageInfo> lst = 
    (from s in enn.Tbl_AdvPackage select new AdvPackageInfo { }).ToList();

You could do this:

var lst = new List<AdvPackageInfo>();
for (int i = 0; i < enn.Tbl_AdvPackage.Count(); i++)
    lst.Add(new AdvPackageInfo());

(Note that the suggested workaround in the MS Connect page is wrong. Using Enumerable.Repeat will create a list full of references to a single object)

---

Update per comment below:
If you’re just trying to load the datagrid, then you just need to retrieve the list as:

var lst = enn.Tbl_AdvPackage.ToList();