CheckedComboBoxEdit is created but cannot be used

Question

I'm trying to add a CheckedComboBoxEdit to a GridView using WinForms and devexpress. This is what I got for now:

using (var _db = new DB())
{
    var isemirleri = _db.IsEmris.AsQueryable();
    var oalist = _db.OperasyonAksakliks.AsQueryable();

    gcIsEmirleri.DataSource = 
     (from i in isemirleri
      select new {
          ID = i.isEmriId,
          İşEmriNo = i.isEmriNo,
          Aksaklık = string.Join(",", 
              oalist
              .Where(o => o.operasyonId == i.Operasyons.FirstOrDefault().operasyonId)
              .Select(o => o.Durus.durusAdi).ToList())
      }).ToList();


    gvIsEmirleri.BeginUpdate();

//------------------------ THIS LINE -------------------------------------\\
    //DataColumn col = new DataColumn("Aksaklık", typeof(string));
//------------------------ THIS LINE -------------------------------------\\
    GridColumn column = gvIsEmirleri.Columns["Aksaklık"];
    column.Caption = "Aksaklık";
    column.Name = "Aksaklık";

    gvIsEmirleri.EndUpdate();

    RepositoryItemCheckedComboBoxEdit chk= new RepositoryItemCheckedComboBoxEdit();
    chk.Items.Clear();  
    foreach (Durus d in _db.Durus.Where(q => q.aksaklikMi == true))
        chk.Items.Add(new ListItem(d.durusId, d.durusAdi));
    chk.EditValueChanged += new EventHandler(chk_EditValueChanged);
    gvIsEmirleri.Columns["Aksaklık"].ColumnEdit = chk;
}

It successfully shows the present Operasyons with commas between and CheckedComboBoxEdits can be seen on the grid (it shows the small button at the right of the cell).

However, the list of elements don't show up when I click on the cell. I debugged the project and observed that chk is set up correctly and holds the Items as meant to be.

If I de-comment the line I marked as THIS LINE and don't add Aksaklık to gcIsEmirleri.DataSource it successfully adds the list and it can be used properly, I can add the checked elements to the related database table, but I cannot see the changes in the view. By that I mean I cannot see the selected elements, as string combined or as checked in the line.

What am I doing wrong or what can I do else to make it work?

Answer 1

The column Aksaklık must be created once. Adding a new GridColumn and assigning DataSource causes the program not to work properly.

So I created a new column while assigning DataSource, named TempColumn, set it's visible to false. After that I added the GridColumn and do the operations as in the code in the question. After that I used UnboundType and get the needed string from TempColumn:

column.UnboundType = DevExpress.Data.UnboundColumnType.String;
column.UnboundExpression = "[TempColumn]";