Question

I have a dropdown list as below:

DropDownList1.DataSource = Students.GetStudents();
DropDownList1.DataBind();
-----------

I have a DataAccess Class as below:

public IEnumerable<StudentEntity> GetStudents()
{
List<StudentsEntity> studentsList = new List<StudentsEntity>();
studentsList = Service.GetList()  // some service getting a list of sutdents

return new BindingList<StudentEntity>(studentsList);
}

I have a DataObject Class as below:

public class StudentEntity : IComparable
{
  public string fullname { get {return firstName +", "+ lastName;}
  public string ID {get; set;}
  public string Height {get; set;}
  public string Firstname {get; set;}
  public string Lastname {get; set;}
  public int CompareTo(object obj)
  {
     StudentEntity entity = (StudentEntity) obj;
     return Lastname.CompareTo(entity.Lastname);
  }
}

At the UI level – the ‘Students Fullname’ is displayed in the dropdown list, so how can I get the ‘ID’ of the Selected Student from the DropDown List?

Answer 1

Get the selected item from the DropDownList and cast it to an object of the type StudentEntity. Afterwards you can get the ID of that object. Pseudo code:

var selectedItem = myDropDown.SelectedItem as StudentEntity;
var ID = selectedItem.ID;

Edit:

‘hvd’ commented me correctly. Since this is in a webcontext, you’ll have to achieve this a bit different. You can set the DataTextField and the DataValueField of the DropDownList. Bind the ID to the DataValueField and when you get the SelectedItem, get the Value-property and you have the ID.

var selectedItem = myDropDown.SelectedItem;
var ID = selectedItem.Value;