Dynamically created groupexpressions are different in the Page_Init then in the Page_Load event

[Ewald]

I have one page and show only one grid. The schema of the grid depends on what action the user selected. When the grid is created I also dynamically set the group.
When the control that was before the postback a RadGrid control, then in the Page_Init event I see that the correct column is used as the groupexpression. In the Page_Load event (which is the next custom code that is running in my app) the groupexpression has been changed to the groupexpressions of the RadGrid that existed before the postback.
My first idea is that it is caused by the viewstate, but I turned off the viewstate of the RadGrid, the MasterTableView and the ColumnViewState of the masterTableView (I am not aware of any other viewstates).
On the first grid or if the control before the postback is another control, everything works fine.

[Radoslav]

Hello Ewald,

Could you please verify that you create the RadGrid properly like is shown in the following online documentation articles:
http://www.telerik.com/help/aspnet-ajax/grid-programmatic-creation.html
http://www.telerik.com/help/aspnet-ajax/grid-changing-structure-dynamically.html
Additionally it will be helpful if you could post your aspx page markup with the related code behind file or send us a runnable project which demonstrates the described problem. Thus we will be able to we debug the project and provide you with more to-the-point answer.

Looking forward for your reply.

Kind regards,
Radoslav
the Telerik team

[Ewald]

Here is a sample app. When I enable the viewstate of the grid, then I see on postback the old data.
When I disable the viewstate I get an error message.

What am I doing wrong?

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<%@ Page Title="Home Page" Language="vb" MasterPageFile="~/Site.Master" AutoEventWireup="false"
CodeBehind="Default.aspx.vb" Inherits="WebApplication1._Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<telerik:RadScriptManager ID="RadScriptManager" runat="server" AsyncPostBackTimeout="0" />
<asp:Button ID="button" runat="server" Text="2e grid" />
<asp:PlaceHolder ID="ph" runat="server" />
</asp:Content>

Imports Telerik.Web.UI

Public Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        ph.Controls.Add(BuildGrid())
    End Sub

    Private Sub button_Click(sender As Object, e As System.EventArgs) Handles button.Click

    End Sub

    Private Function BuildGrid() As RadGrid
        Dim groupcolumn = "isPostback_is_" + Page.IsPostBack.ToString()

        Dim ret = New RadGrid() With {
                .EnableViewState = True,
                .ID = "myId",
                .AutoGenerateColumns = False
                }

        ret.MasterTableView.EnableColumnsViewState = False
        ret.GroupingEnabled = True

        AddHandler ret.NeedDataSource, Sub(sender As Object, e As GridNeedDataSourceEventArgs)
                                           Dim dt As New DataTable

                                           dt.Columns.Add("Id", GetType(Integer))
                                           dt.Columns.Add(groupcolumn, GetType(Integer))

                                           If Not Page.IsPostBack Then
                                               dt.LoadDataRow(New Object() {1, 1}, True)
                                               dt.LoadDataRow(New Object() {2, 2}, True)
                                           Else
                                               dt.LoadDataRow(New Object() {3, 3}, True)
                                               dt.LoadDataRow(New Object() {4, 4}, True)
                                           End If

                                           ret.DataSource = dt
                                       End Sub

        ret.Columns.Add(New GridBoundColumn() With {.DataField = "Id"})
        ret.Columns.Add(New GridBoundColumn() With {.DataField = groupcolumn})

        ret.MasterTableView.GroupByExpressions.Add(New GridGroupByExpression(String.Format("{0} GROUP BY {0} ASC", groupcolumn)))

        Return ret
    End Function
End Class

[Radoslav]

Hi Ewald,

Could you please try enabling the ViewState of the RadGrid's columns and let me know if the issue still persists:

Private Function BuildGrid() As RadGrid
...
   ret.MasterTableView.EnableColumnsViewState = True
...

End Function

Regards,
Radoslav
the Telerik team

[Ewald]

The problem still persits when changing that property

[Radoslav]

Hi Ewald,

Could you please try disabling the ViewState of the  PlaceHolder control and let me know if the issue still persists:

<asp:PlaceHolder ID="ph" EnableViewState="false" runat="server" />

Looking forward for your reply.

Kind regards,
Radoslav
the Telerik team

[Ewald]

I don't know what change I did in my code, but it now works.

Thanks for you support anyway.