Would this also work for a ListBox?

Yes, I see. Unfortunately this is not a suported scenario -- EditorControlID uses interface that is only supported by Infragistics "editor" controls - like WebCombo, WebDataChooser, WebTextBox, WebPercentEdit, etc. Stock controls like multi-select asp:ListBox are not supported.

The closest I see to this would be using RowEditTemplate and placing the listbox inside the template.

Indeed, a bit more information is needed.

 I know that upon editing a row, you can use different controls one of which being ColumnType.Custom
What I'm looking for is this:

I've got a webgrid containing information that can be edited. One of these columns should be able
to open a Listbox from which several items can be selected. the selected items would then be placed in the cell
as 'Item1;Item3;Item...'

I was wondering if I could use the Columntype.Custom and then give the ID of a Listbox in
the UltraGridColumn.EditorControlID

 HTH

Hello,

I am not exactly sure I understand the question about ListBox -- do you mean asp:dropdown? If so, the dropdown is not supported as a custom edtitor -- this is only supported by the Infragistics editor controls. You have a few alternatives:

1. Use infragisics WebCombo instead of asp:dropdown

2. Use the specil GridColumn of Type "DropDown" the grid support

3. Use templated column and place anything you wish inside the CellTemplate of the column.

HTH,