winforms - How to prevent combobox changing together? -

i have windows form 2 combo boxes on , fill list.

when change fist combo box value why second combo box value changing first one?

how can prevent it?

i set no event or can cause problem.

        list<myclass> mc = new list<myclass>();         mc.add(new myclass() {  id = 10, name = "no 10" });         mc.add(new myclass() { id = 27, name = "no 27" });          combobox1.datasource = mc;         combobox1.valuemember = "id";         combobox1.displaymember = "name";          combobox2.datasource = mc;         combobox2.valuemember = "id";         combobox2.displaymember = "name"; 

my class :

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

it works because comboboxes have same datasource. try copying or cloning list comboboxes have independent datasources.