Failed to load viewstate after closing radwindow

[John]

Hello,

   I am getting an error with the viewstate. I need to do some stuff in the code behind of the child radwindow prior to closing it. Then I need to do some other tasks on the parent form. After I click the close window of the child radwindow and then click the button on the parent form I get the message "Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request. " I am new to this and have read the __doPostBack, but am not sure if I need that or where to start. I would appreciate any insight. I have supplied the code below. Thanks.

John

parentForm

aspx

<

html xmlns="http://www.w3.org/1999/xhtml" >

<

head runat="server">

<title>Untitled Page</title>

</

head>

<

body>

<form id="form1" runat="server">

<telerik:radscriptmanager id="ScriptManager1" runat="server" enabletheming="True"></telerik:radscriptmanager>

<div>

</div>

<telerik:radwindowmanager id="RadWindowManager1" runat="server" behavior="Default"

initialbehavior="None" left="" top=""></telerik:radwindowmanager>

<asp:Button ID="Button1" runat="server" Text="Button" />

</form>

</

body>

</

html>

code behind

Public

Partial Class frmMDI

Inherits System.Web.UI.Page

Dim newWindow1 As New Telerik.Web.UI.RadWindow()

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

If Not IsPostBack Then

Try

'create child modal window

newWindow1.Behaviors = Telerik.Web.UI.WindowBehaviors.Move

newWindow1.Height =

"320"

newWindow1.Width =

"422"

newWindow1.Title =

"Child Window"

newWindow1.Modal =

True

newWindow1.VisibleTitlebar =

False

newWindow1.VisibleOnPageLoad =

True

newWindow1.NavigateUrl =

"frmChild.aspx"

newWindow1.Visible =

True

newWindow1.DestroyOnClose =

True

RadWindowManager1.Windows.Add(newWindow1)

Catch ex As Exception

Dim strEr As String = ex.ToString

End Try

Else

End If

End Sub

Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

'do some code behind

Button1.Text =

"Refreshed"

End Sub

End

Class

child form

aspx

<

html xmlns="http://www.w3.org/1999/xhtml" >

<

head runat="server">

<title>Child Window</title>

<script type="text/javascript">

function get_RadWindow() //verify that it's a radWindow

{

var oWindow = null;

if (window.radWindow)

{ oWindow = window.radWindow; }

else if (window.frameElement.radWindow)

{ oWindow = window.frameElement.radWindow; }

return oWindow;

}

function JustClose()

{

get_RadWindow().Close();

}

</script>

</

head>

<

body>

<form id="form1" runat="server">

<telerik:RadScriptManager ID="ScriptManager1" runat="server" EnableTheming="True">

</telerik:RadScriptManager>

<telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">

</telerik:RadAjaxManager>

<telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server" Height="200px" Width="300px">

<asp:Button ID="Button1" runat="server" Text="Close Window" /></telerik:RadAjaxPanel>

</form>

</

body>

</

html>

code behind

Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

'do some code behind

RadAjaxManager1.ResponseScripts.Add(

"JustClose()")

End Sub

[Georgi Tunev]

Hello John,

This behavior is expected - in the initial page load, you create a control, but after the postback this control does not exist. This raises the error - "The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request."

What I suggest in your case is to create the RadWindow in Page_Load and in your if/else statement to set only its VisibleOnPageLoad property accordingly to your logic:

Partial Class ViewStateProblem_Default
    Inherits System.Web.UI.Page
    Dim newWindow1 As New Telerik.Web.UI.RadWindow()

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        newWindow1.Behaviors = Telerik.Web.UI.WindowBehaviors.Move
        newWindow1.Height = "320"
        newWindow1.Width = "422"
        newWindow1.Title = "Child Window"
        newWindow1.Modal = True
        newWindow1.VisibleTitlebar = False

        newWindow1.NavigateUrl = "frmChild.aspx"
        newWindow1.Visible = True
        newWindow1.DestroyOnClose = True
        RadWindowManager1.Windows.Add(newWindow1)

        If Not IsPostBack Then

            Try

                'create child modal window

                newWindow1.VisibleOnPageLoad = True
            Catch ex As Exception
                Dim strEr As String = ex.ToString
            End Try
        Else
            newWindow1.VisibleOnPageLoad = False
        End If
    End Sub
    Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        'do some code behind

        Button1.Text = "Refreshed"

    End Sub
End Class

Regards,
Georgi Tunev
the Telerik team

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