UserControls in dynamically created PanelBarItems lost on Postack

[Tamayi]

What I'm trying to do is perhaps pretty simple:

• Allow the user to select several configuration options from a drop down list.
• Each configuration option has a user control associated with it and when the user selects the option, the User Control with the configuration details must display allowing the user to capture some info.
• The user can select any number of configuration options, and this in itself might result in a very loooong form as more configuration choices are selected.

I'm hoping RadPanelBar can help prevent the form growing too long by allowing collapseing behaviour in the configuration section for me.

I keep track of the choices which the user has selected (in a hidden form variable) , and with each choice, the specific user control which must be loaded. The problem I'm currently facing is that the RadPanelBar only displays the very last item on PostBack, losing the controls from all previous choices. I reload the controls in the Page_Init event.

Private Property MyUsedControls As Dictionary(Of Long, MyUsedControl)

Private Sub Page_Init(sender As Object, e As System.EventArgs) Handles Me.Init

    MyUsedControls = MyUsedControl.DeserializeReportList(Request.Form(HiddenField1.UniqueID))

    'Recreate the controls. At this stage, the RadPanelBar1.Items collection is empty
    For i As Integer = 0 To MyUsedControls.Count - 1

        Dim ctrl As MyUsedControl = MyUsedControls(i)
        AddConfigurationControl(ctrl.ControlPath)

    Next

End Sub

Private Sub AddConfigurationControl(ByVal cPath As String)

    Dim p As New RadPanelItem("Control No. " & RadPanelBar1.Items.Count)
    Dim uc As Control = LoadControl(cPath)

    Dim content As New RadPanelItem()
    content.Controls.Add(uc)

    p.Items.Add(content)

    RadPanelBar1.Items.Add(p)

End Sub

Protected Sub RadComboBox1_SelectedIndexChanged(sender As Object, e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs) Handles RadComboBox1.SelectedIndexChanged

    'Here we add the control to our "memory" of what controls we have so far used
    'This is persisted into a hidden form variable without any problems
    MyUsedControls.Add(
        MyUsedControls.Count,
        New MyUsedControl With {
            .ID = RadPanelBar1.Items.Count,
            .ControlPath = RadComboBox1.SelectedValue
        }
    )

    AddConfigurationControl(RadComboBox1.SelectedValue)

    RadComboBox1.ClearSelection()

End Sub

You can download a copy of the source code here: Sample Code: RadControlsWebApp1 (link expires 19 August 2012)

[Peter]

Hello Tamayi,

Can you specify the exact version of Telerik controls and .NET that you are using? Have you tried with the latest version from the Q2 2012 release for .NET 4.0?

Kind regards,
Peter
the Telerik team

[Tamayi]

I am using the latest version of Telerik 2012.2.607.35 on .NET 3.5