model view controller - Convert an object into list or array MVC -

i have mvc grid control passing collection controller object. object arraylist of rows grid , each row list represents instance of class called lineitem part of parent record class.

i trying load object class looping through object array, create instance of lineitem class, , add parent record class parent.additem(lineitem). had created follows

var items = requestdata.extrarequestdata["items"]; 

however determined, arraylist changed to

list<string> mylist;     arraylist items = (arraylist)requestdata.extrarequestdata["items"]; mylist = items.cast<string>().tolist(); 

i trying convert arraylist list can loop through , load class.

model.parent parent = new model.parent(); model.lineitem lineitem = new model.lineitem();  (int = 0; < mylist.length; i++){         lineitem.a = item.a,        lineitem.b = item.b parent.additem(lineitem) } 

i getting following error on line set mylist = items:

{"unable cast object of type 'system.collections.hashtable' type 'system.string'."} 

what missing convert can load class?

since each item in arraylist hashtable, ended looping through follows: parentclass reconhdr = new parentclass();

            foreach (system.collections.hashtable  o in items)             {                //lineitem.lineseq = convert.toint32(item.value);                 arraylist list = new arraylist(o.values);                 childclass lineitem = new childclass();                  lineitem.stmntdocnum = list[0].tostring();                 lineitem.prtlamt = convert.todouble(list[1]);                 lineitem.glacctcode = list[2].tostring();                 lineitem.lineseq = convert.toint32(list[3]);                 lineitem.clinicid = convert.toint32(list[4]);                 lineitem.prtltrandate = convert.todatetime(list[5]);                 lineitem.stmnttrandate = convert.todatetime(list[6]);                 lineitem.prtlfinrptdate = convert.todatetime(list[7]);                 lineitem.stmntenddate = convert.todatetime(list[8]);                 lineitem.stmntamt = convert.todouble(list[9]);                 lineitem.prtldocnum = list[10].tostring();                 lineitem.prtluniqueid = list[11].tostring();                  reconhdr.additem(lineitem);              }