How to append two field values in combobox display member in C#

Question

In my table, I have a field of firstname and lastname, now what I want is to set firstname and lastname as displaym

Answer 1

in C# 6 create readonly property in your Employee class

public string FullName=>$"{lastname} {firstname}";

then

cmbEmployees.DataSource = GetEmployees();
//something like below line which doesn't work
cmbEmployees.DisplayMember = "FullName";     
cmbEmployees.ValueMember = "id";