Add editor to PropertyGridParameter created in AjaxEvent

[amgw]

I am setting PropertyGridParameters in an AjaxEvent. The properties are being added successfully, but the editor type is not being set. What am I doing wrong?

            For Each row As DataRow In dt.Rows
                Dim param As New PropertyGridParameter
                param.Name = row("Name")
                param.Value = row("Value")
                param.Editor.Add(New Coolite.Ext.Web.DateField())
                PropertyGrid1.Source.Add(param)
            Next

        PropertyGrid1.SetSource(PropertyGrid1.Source)