try this one.
protected void FillDrpEmpInfo()
{
dtTemp = new DataTable();
dtTemp = CreateEmpDataTable();
dtTemp.Columns.Add("Displaly", typeof(string), "ID + ' - ' + Name + ' ' + Surname");
this.drpEmpInfo.DataSource = dtTemp;
this.drpEmpInfo.DataTextField = "Displaly";
this.drpEmpInfo.DataValueField = "ID";
this.drpEmpInfo.DataBind();
}
public DataTable CreateEmpDataTable()
{
dt = new DataTable();
dt.Columns.Add("ID");
dt.Columns.Add("Name");
dt.Columns.Add("Surname");
dt.Columns.Add("Salary");
dt.Columns.Add("Designation");
dt.Rows.Add("1", "KiranKumar", "Roy", "5500", "Web Developer");
dt.Rows.Add("2", "Hetvi", "Roy", "4500", "Web Developer");
dt.Rows.Add("3", "Shankar", "Shetty", "7500", "Support Engg");
dt.Rows.Add("4", "Loe", "Louis", "6500", "Support Engg");
dt.Rows.Add("5", "Sanaj", "Meppery", "8000", "Sales Executive");
dt.Rows.Add("6", "Jubair", "Mohd", "7000", "DNN Developer");
dt.Rows.Add("7", "Sanjay", "Nadher", "5000", "CA");
dt.Rows.Add("8", "Jyoti", "Ramwani", "3000", "Receptionist");
dt.Rows.Add("9", "Sajid", "Shahid", "10000", "Sales and Techanical Manager");
dt.Rows.Add("10", "Vijay", "Roy", "10000", "Glass Artist");
return dt;
}