I really like working with the Telerik ASP.NET AJAX controls. However, I keep forgetting about a problem in the RadGrid that occurs when trying to add a new record using EntityDataSource. If there aren’t any records yet, and you click Add Record, you often get this:
DataBinding: 'Telerik.Web.UI.GridInsertionObject' does not contain a property with the name ‘<fieldname>'.
The workaround is to manually initialize the object being inserted. Here’s the routine (VB) for my future reference and yours:
Protected Sub RadGrid1_ItemCommand _
(ByVal source As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs) _
' For error 'Telerik.WebControls.GridInsertionObject' does not contain a property
' Handles the case where you are adding a new item to the grid where
' none exists yet. The purpose is to create a dummy collection of values
' to prefill the form
If e.CommandName = RadGrid.InitInsertCommandName Then
e.Canceled = True
Dim newValues As System.Collections.Specialized.ListDictionary = _
newValues("Note") = ""
newValues("DisplayOrder") = 0
newValues("ID") = 0
'Insert the item and rebind
Full Disclosure: Telerik gave me a copy of their controls as a perk for being a Microsoft MVP for ASP.NET.