c# - WPF DataGrid Editing Difficulty (InvalidOperationException) -

i have datagrid filling information observablecollection<observablecollection<t>> t object of mine implements ieditableobject.

i have datagrid correctly filling information need. problem when go edit box in exception.

system.invalidoperationexception: 'edititem' not allowed view 

followed subsequent stack trace.

i understand binding idea in observablecollection<t> if want able edit datagrid items need implement ieditableobject interface in object t.

i'm not sure why won't let me edit, although i'm leaning more towards idea need attach object type of view.

i've not found on i'm trying have been successful until point in getting on hurdles. if has insight should appreciated.

also, post code if see believe it's less i've written , more still need write.

edit: added code

private void dg_datacontextchanged(object sender, dependencypropertychangedeventargs e)     {         datagrid grid = sender datagrid;         grid.columns.clear();         tablenode node = e.newvalue tablenode;         if (node != null)         {             infotable dti = new infotable(m_model.editnode.database.path, node.fullname);             int index = 0;             foreach (string colname in dti.columns)             {                 datagridtextcolumn col = new datagridtextcolumn();                 col.header = colname;                 col.binding = new binding("[" + index + "].info");                 //note: .info information string in class t containing data may or may not edited                 grid.columns.add(col);                 index++;             }             grid.itemssource = dti;         }     } 

here binding columns each observablecollection in observablecollection<observablecollections<t>> in infotable. have implemented ienumerable , inotfiypropertychange in infotable.

i'm pretty sure infotable class needs implement ilist, too, in order support datagrid editing.

ilist adds capability of adding , removing items, , datagrid needs manage rows.