C#

public class ComboItemEx
{
private int id;
private string name;
private string address;
public int ID
{
get
{
 return id;
}
set
{
id=value;
}
}
public string Name
{
get
{
return name ;
}
set
{
name=value;
 }
}
public string Address
{
return address;
}
set
{
address=value;
}
public override ToString()
{
// return what you want to display in combobox
  return name;
}
}
and some where you can add it
CombobItemEx cbi=new CombobItemEx();
cbi.ID=44;
cbi.Name="my name";
cbi.Address="my address"
comboBox1.Items.Add(cbi)