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RadGrid filtering throws null reference exception when inside a RadWindow

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Grid

This is a migrated thread and some comments may be shown as answers.

Josh asked on 20 Sep 2011, 09:36 PM

I have a RadGrid in a RadWindow. When I try to filter the grid it does a postback and throws this exception:

[NullReferenceException: Object reference not set to an instance of an object.]
Telerik.Web.UI.RadGrid.RaisePostBackEvent(String eventArgument) +9792
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +175
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565

I found that if I put another RadGrid on the page not in a RadWindow and filter it first, then filter the RadGrid in the window, it works correctly.

To reproduce: click "Open RadWindow", enter "5" in Title filter, click the filter icon for the Title column and select "Contains"

Code:

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="RadGridTest.aspx.vb" Inherits="RadGridTest" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Charting" TagPrefix="telerik" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

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

<head runat="server">

<title></title>

</head>

<body>

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

<div>

<asp:ScriptManager ID="ScriptManager1" runat="server">

</asp:ScriptManager>

<a href="javascript:$find('RadWindow1').show();">Open RadWindow</a>

<telerik:RadWindowManager ID="RadWindowManager1" runat="server" EnableShadow="True" VisibleTitlebar="true" VisibleStatusbar="false">

<Windows>

<telerik:RadWindow ID="RadWindow1" runat="server" Title="Change Dashboard" Width="500" Modal="true">

<ContentTemplate>

<telerik:RadGrid ID="RadGrid1" runat="server" PageSize="10" AllowPaging="true" AllowSorting="true">

<GroupingSettings CaseSensitive="false" />

<MasterTableView AutoGenerateColumns="false" AllowFilteringByColumn="true">

<Columns>

<telerik:GridTemplateColumn AllowFiltering="false">

<ItemTemplate>

<asp:HyperLink ID="lnkSelect" runat="server" NavigateUrl='/Default.aspx'>Select</asp:HyperLink>

</ItemTemplate>

</telerik:GridTemplateColumn>

<telerik:GridBoundColumn HeaderText="Title" DataField="Title" SortExpression="Title" />

<telerik:GridBoundColumn HeaderText="Description" DataField="Description" SortExpression="Description" />

</Columns>

</MasterTableView>

</telerik:RadGrid>

</ContentTemplate>

</telerik:RadWindow>

</Windows>

</telerik:RadWindowManager>

</div>

<div>

<telerik:RadGrid ID="RadGrid2" runat="server" PageSize="10" AllowPaging="true" AllowSorting="true">

<GroupingSettings CaseSensitive="false" />

<MasterTableView AutoGenerateColumns="false" AllowFilteringByColumn="true">

<Columns>

<telerik:GridTemplateColumn AllowFiltering="false">

<ItemTemplate>

<asp:HyperLink ID="lnkSelect" runat="server" NavigateUrl='/Default.aspx'>Select</asp:HyperLink>

</ItemTemplate>

</telerik:GridTemplateColumn>

<telerik:GridBoundColumn HeaderText="Title" DataField="Title" SortExpression="Title" />

<telerik:GridBoundColumn HeaderText="Description" DataField="Description" SortExpression="Description" />

</Columns>

</MasterTableView>

</telerik:RadGrid>

</div>

</form>

</body>

</html>

Imports Telerik.Web.UI

Imports Telerik.Charting

Imports System.Data

Partial Class RadGridTest

Inherits System.Web.UI.Page

Private Shared Function GetGridDataTable() As DataTable

Dim GridDataTable As New DataTable()

GridDataTable.Columns.Add(New DataColumn("Title", System.Type.GetType("System.String")))

GridDataTable.Columns.Add(New DataColumn("Description", System.Type.GetType("System.String")))

For i As Integer = 0 To 4

Dim Row As DataRow = GridDataTable.NewRow()

Row.SetField("Title", "Title " & i)

Row.SetField("Description", "Description " & i)

GridDataTable.Rows.Add(Row)

Next

Return GridDataTable

End Function

Protected Sub RadGrid1_NeedDataSource(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RadGrid1.NeedDataSource

RadGrid1.DataSource = GetGridDataTable()

End Sub

Protected Sub RadGrid2_NeedDataSource(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RadGrid2.NeedDataSource

RadGrid2.DataSource = GetGridDataTable()

End Sub

End Class

4 Answers, 1 is accepted

answered on 26 Sep 2011, 05:09 PM

Hi Josh,

To fix the problem you should put the RadWindow with ContentTemplate outside the Windows collection of the RadWindowManager and use it as a separate control. You can show it by using show() instead of radopen/open.

The problem you report comes from the fact that your RadWindow with ContentTemplate is added in a RadWindowManager Windows and Controls collections. At some point the RadWindowManager needs to clear its child controls and this is what causes the problem. The scenario of having a RadWindow with ContentTemplate declared in the RadWindowManager is not valid itself - it works for simple cases but the actual design purpose of the manager is to dynamically create RadWindow containers on the client and a RadWindow with ContentTemplate cannot be dynamically created on the client. We are aware of the issue and it is logged in our TODO for future investigation and improvement. However, I cannot give you a time estimate when it will be addressed due to the specifics of the problem, already set priorities and the fact that there is a simple and correct solution.

Please, test my suggestion of moving the RadWindow outside the manager and let me know how it goes or in case you need any assistance.

All the best,
Svetlina Anati
the Telerik team

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