problems setting XtraGrid with in-place editor-s (using GridLookUpEdit) - winforms

Question

I need an XtraGrid control that has GridLookupEdit to enter column values.
What I managed to do so far:
1) I have configured XtraGrid control
columns: ID, Name, Number
in-place GridLookUp Editors for Name and Number columns
2) on the form Load event I load data from database and set XtraGrid datasource and both repositoryItem(..) datasource, valuemember and displaymember
a) Data are loaded in XtraGrid, I can activate cell but can not choose values from dropdown (from repositoryItem(..)) or enter values manually (i can activate cell in "*" new row but it has the same problem - can not choose from the dropdown or enter values manually) => why?
b) If I don't set datasource for XtraGrid, then both dropdown's are active and i can select values using GridLookupEdit, but when i exit the cell, the cell gets cleared => i believe this is because in this case no xtraGrid.DataSource is set?
var model = (from TableA a in _dbE.TableA select new {ID, Name, Number}).ToList();
//if i comment this line out, then i can choose values from GridLookUpEdit
gridControl1.DataSource = model;
repositoryItemNosaukums.DataSource = model;
repositoryItemNosaukums.ValueMember = "ID";
repositoryItemNosaukums.DisplayMember = "Name";
repositoryItemPieteikumaNr.DataSource = model;
repositoryItemPieteikumaNr.ValueMember = "ID";
repositoryItemPieteikumaNr.DisplayMember = "Number";
What am I missing?

Answer 1

The problem was, that my data source "model" was a List, but it should have been BindingList with properties AllowNew==True and AllowEdit==True.
After DevExpress support asked if the data source is read only, i found this post which finally opened my eyes:
A Problem in DataGridView : datagridview seems readonly to user (WinForms)
correct version of code
//no projections (select new ...) for IBindingList<T>..
//var model = (from TableA a in _dbE.TableA select new {ID, Name, Number}).ToList();
var model = (from TableA a in _dbE.TableA).ToList();
//convert to BindingList
var bindingModel= new BindingList<TableA>(model);
bindingModel.AllowNew=true;
bindingModel.AllowEdit=true;
//bind BindingList to datagrid
gridControl1.DataSource = bindingModel; //model;
//... no changes to repositoryItem(..) stuff
repositoryItemNosaukums.DataSource = model;
repositoryItemNosaukums.ValueMember = "ID";
repositoryItemNosaukums.DisplayMember = "Name";
repositoryItemPieteikumaNr.DataSource = model;
repositoryItemPieteikumaNr.ValueMember = "ID";
repositoryItemPieteikumaNr.DisplayMember = "Number";