Question

I am trying to do this:

protected void Page_Load(object sender, EventArgs e)
{
   Group g = SecurityManager.GetGroup("Programmers");

   IEnumerable<EmployeGroup> emps = 
       SecurityManager.GetEmployeesByGroup(g.GroupID);
   ListBox1.DataSource = emps;
   ListBox1.DataTextField = "Employee.EmployeName";
   ListBox1.DataBind();
}

Inside an EmployeGroup there is an Employee and a Group.
I want to show the Employee’s EmployeName member.

Is there some way to do this without doing:
for each Employee. Add to listbox.

Answer 1

You have a few choices. You can either extend the Employee class and introduce a new property called EmployeeNameAndId

public string EmployeeNameAndId 
{ 
       get 
       { 
          return String.Format("{0} ({1})", EmployeeName, EmployeeId); 
       }
}

Another option is overriding the OnDataBinding event and concatenate the two properties there. I don’t recommend this; it’s lousy encapsulation among other reasons, but I wanted you to be aware of the option.

The final option is to create an intermediate data source from your query and bind to that:

var employees = SecurityManager.GetEmployeesByGroup(g.GroupID).Select(e => new { EmployeeNameAndId = e.EmployeeName + " (" + e.EmployeeId + ")"});

ListBox1.DataSource = employees ;
ListBox1.DataTextField = "EmployeeNameAndId";
ListBox1.DataBind();