c# - Insert Custom value at top of Databound ComboBOX -

i want insert default value @ top of combobox. please tell me proper way so.

what tried

my code:

 using (var salaryslipentities = new salary_slipentities())             {                     employee emp = new employee();                       cmbemployeename.datasource = salaryslipentities.employees.tolist();                          cmbemployeename.items.insert(0, "select employee");                           } 

error

items collection cannot modified when datasource property set.

you can using system.reflection. check code sample below.

write common method add default item.

 private void additem(ilist list, type type, string valuemember,string displaymember, string displaytext)     {         //creates instance of specified type          //using constructor best matches specified parameters.         object obj = activator.createinstance(type);          // gets display property information         propertyinfo displayproperty = type.getproperty(displaymember);          // sets required text display property         displayproperty.setvalue(obj, displaytext, null);          // gets value property information         propertyinfo valueproperty = type.getproperty(valuemember);          // sets required value value property         valueproperty.setvalue(obj, -1, null);          // insert new object on list         list.insert(0, obj);     } 

then use method this.

list<test> tests = new list<test>();         tests.add(new test { id = 1, name = "name 1" });         tests.add(new test { id = 2, name = "name 2" });         tests.add(new test { id = 3, name = "name 3" });         tests.add(new test { id = 4, name = "name 4" });          additem(tests, typeof(test), "id", "name", "< select option >");         combobox1.datasource = tests;         combobox1.valuemember = "id";         combobox1.displaymember = "name"; 

i used test class in code

public class test {     public int id { get; set; }     public string name { get; set; } }