stringArray = Array.ConvertAll(Of Object, String)(objArray, AddressOf Convert.ToString)

cbobox.datasource = al

I did not try to duplicate this effect but the solution I used was to iterate through the members of the arraylist and individually add items to the combobox.

For i = 0 to al.count-1

cbobox.list.add(al(i))

next

And here is the VB version:

   Private Sub dgvMacroGrid_EditingControlShowing(ByVal sender As Object,
            ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs)
            Handles dgvMacroGrid.EditingControlShowing
      'Enable text editing in combo cells
      If (dgvMacroGrid.CurrentCellAddress.X = colMacroLookup.DisplayIndex) Then
         Dim cb As ComboBox = CType(e.Control, ComboBox)
         If (cb IsNot Nothing) Then
            cb.DropDownStyle = ComboBoxStyle.DropDown
         End If
      End If
   End Sub

Notes:

1. Assign routine to both Entry and Exit events
2. Routine will work with both mouse and tab/spacebar. With tab, 2 boxes may simultaneously appear checked until you exit the selected checkbox.
3. I trapped some kind of strange bug that occurred for me in Table cells. Details in the code.

Sub MakeCheckBoxesExclusive()

   Dim oField As FormField
   Dim oCheckedField As FormField
   Dim bChecked As Boolean
   Dim oContainer As Object

   On Error GoTo errtrap

   '\ Figure out if checkboxes are grouped by frame or table cell
   If Selection.Frames.Count > 0 Then
      Set oContainer = Selection.Frames(1)
   ElseIf Selection.Cells.Count > 0 Then
      Set oContainer = Selection.Cells(1)
   End If

   '\Get the value of the current checkbox
   '\If it is checked then it will be the checked box
   bChecked = Selection.FormFields(1).CheckBox.Value
   If bChecked Then
      Set oCheckedField = Selection.FormFields(1)
   Else
      '\Selected box is not checked
      '\Look through other boxes for checked box
      For Each oField In oContainer.Range.FormFields
         If oField.CheckBox.Value = True Then
            Set oCheckedField = oField
            Exit For
next_field:
         End If
      Next oField
   End If

   '\Uncheck all the boxes
   For Each oField In oContainer.Range.FormFields
      oField.CheckBox.Value = False
   Next oField

   '\Check the designated box
   If Not oCheckedField Is Nothing Then
      oCheckedField.CheckBox.Value = True
   End If

   Exit Sub

   errtrap:
   '\ This error occurred when enumerating formfields in table cells
   '\ Some fields enumerated as strings or numbers
   If Err.Number = 4120 Then
      Resume next_field
   Else
      Err.Raise Err.Number
   End If

End Sub

It won’t be entirely painless. A few of the keyboard shortcuts are different, and some Flash content doesn’t load (YouTube has no problem), but I’ve had no problem with any Ajax apps and it is worth it for me.