Related Combmoxes in grid, SelectedValue always blank!

[Tim]

No matter what I try, the SelectedValue of the CountryCombo is always null, therefore I cannot load the Province/State Combo?

<telerik:RadComboBox ID="CountryCombo" runat="server" EnableLoadonDemand="true">
</telerik:RadComboBox>
 <telerik:RadComboBox ID="ProvinceCombo" runat="server" Width="325" EnableLoadonDemand="true">
</telerik:RadComboBox>

Private Sub RecipientsGrid_NeedDataSource(sender As Object, e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RecipientsGrid.NeedDataSource

 

Dim ctx As New DataEntities

 

RecipientsGrid.DataSource = ctx.RecipientOrganizations.ToList

 

AddOrganizationButton.Visible = False

RecipientOrganizationComboBox.Visible = False

 

   End Sub
    Private Sub RecipientsGrid_ItemCreated(sender As Object, e As Telerik.Web.UI.GridItemEventArgs) Handles RecipientsGrid.ItemCreated
       If TypeOf e.Item Is GridEditableItem AndAlso e.Item.IsInEditMode Then

            Dim editedItem As GridEditableItem = TryCast(e.Item, GridEditableItem)
            Dim CountryCombo As RadComboBox = TryCast(editedItem.FindControl("CountryCombo"), RadComboBox)
            Dim ProvinceCombo As RadComboBox = TryCast(editedItem.FindControl("ProvinceCombo"), RadComboBox)

            AddHandler CountryCombo.ItemsRequested, AddressOf CountryCombo_ItemsRequested
            AddHandler ProvinceCombo.ItemsRequested, AddressOf ProvinceCombo_ItemsRequested

        End If
    End Sub
    Private Sub CountryCombo_ItemsRequested(sender As Object, e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs)

        Dim Combo As RadComboBox = sender

        LoadCountries(Combo)

    End Sub

    Private Sub ProvinceCombo_ItemsRequested(sender As Object, e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs)

        Dim Combo As RadComboBox = CType(sender, RadComboBox)
        Dim editedItem As GridEditableItem = CType(Combo.NamingContainer, GridEditableItem)
        Dim CountryCombo As RadComboBox = CType(editedItem.FindControl("CountryCombo"), RadComboBox)

        Dim _item As New RadComboBoxItemData()

        LoadProvinces(_item.Value, Combo)

    End Sub
   Protected Sub LoadCountries(ByVal Control As RadComboBox)

        Using context As New DataEntities
            With Control
                .DataValueField = "CountryId"
                .DataTextField = "CountryName"
                .DataSource = context.Countries.OrderBy(Function(x) x.displayOrder).ToList
            End With
            Control.Width = Unit.Pixel(320)
            Control.DataBind()
        End Using

    End Sub

[Boyan Dimitrov]

Hello Tim,

Here you can find a Code Library that uses cascading RadComboBoxes  in RadGrid Insert/Edit form. The implemented scenario is pretty close to your requirement.

Hope this will lead you into right direction.


Greetings,
Boyan Dimitrov
the Telerik team