How to update dropdownlist in gridview

See more:

C#5.0

I have a gridview in my form,in which there is dropdownlist that is fill up using following code

DropDownList ddlEmployee = (DropDownList)row.FindControl("ddlEmp");
                  DropDownList ddlEmployee2 = (DropDownList)row.FindControl("ddlEmp2");
                  var Emplist1 = _service.GetAllSectorEmployee();
                  ddlEmployee.Bind(Emplist1, "EmployeeIdName", "Employee_Id");
                  ddlEmployee2.Bind(Emplist1, "EmployeeIdName", "Employee_Id");

i have a requirement that when ever employee is selected ,then it will remove from list,i have done it using following code,

var removelist = _service.GetAllSectorEmployee().Where(x => x.Employee_Id == Emp2).FirstOrDefault();
                       _service.DeleteSectorEmployee(removelist);

problem is that when employee is removed ,dropdownlist will be updated and also remove that employee.how can i do it? i try following code but fruitless

DropDownList ddlEmployee = (DropDownList)row.FindControl("ddlEmp");
                        DropDownList ddlEmployee2 = (DropDownList)row.FindControl("ddlEmp2");
                        var Emplist1 = _service.GetAllSectorEmployee();
                        ddlEmployee.Bind(Emplist1, "EmployeeIdName", "Employee_Id");
                        ddlEmployee2.Bind(Emplist1, "EmployeeIdName", "Employee_Id");