Question

I’m using a function to return a number of years calculated from a datetime column, and am having trouble figuring out how to reference the calculated column when trying to populate a dropdown.

Here is my Linq query:

 var q = (from a in db.Applications
          where a.uID == ID
          select a.date.Year).Distinct();
 return q.ToList();

So, when I go to populate the dropdown…

Dropdown1.DataTextField = ?????

Answer 1

When a list of value types is used as the DataSource, the DataTextField and DataValueField properties do not need to be set.

See below:

private List<int> GetYears()
{
    var q = (from a in db.Applications
             where a.uID == ID
             select a.date.Year).Distinct();

    return q.ToList();
}

The dropdown would then be initialized like this:

Dropdown1.DataSource = GetYears();
// Dropdown1.DataTextField = null;  // Does not need to be set
// Dropdown1.DataValueField = null; // Does not need to be set