how to make asp dropdownlist accept null values when databinding

Question

I am trying to populate a dropdownlist with the following LINQ statement

var beskeder = from b in db.beskeds
            join v in db.vedhaeftedeFilers on b.beskedId equals v.beskedId into x
            from v in x.DefaultIfEmpty()
            select new
            {
                beskedId = b.beskedId,
                tekst = b.tekst,
                dato = b.dato,
                behandlet = b.behandlet,
                medlemsid = b.medlemsid,
                dokumentid = b.dokumentId,
                filid = v.filId,
                filnavn = v.filnavn,
                filtype = v.filtype,
                data = v.data,
                DisplayText = "Besked fra bruger " + b.medlemsid.ToString() + ", " + b.dato
            };

DropDownList1.DataSource = beskeder;
DropDownList1.DataValueField = "medlemsid";
DropDownList1.DataTextField = "DisplayText";
DropDownList1.DataBind();

but i get a errormessage

The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type.

i know it's because it won't accept null values. How do i make the dropdownlist accept null values. I would appreciate syntax examples

Saeed Neamati · Accepted Answer · 2011-12-09 12:28:55Z

1

I propose that you change your strategy, and either remove items with null value, or set a default value for them, because you're using LINQ projection (you create new anonymous type). For example you can write:

 select new
 {
      medlemsid = b.medlemsid == null ? 0 : b.medlemsid
 };

in your projection, to convert nulls into 0

answered Dec 9, 2011 at 12:28

Saeed Neamati

35.9k42 gold badges140 silver badges192 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

how to make asp dropdownlist accept null values when databinding

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related