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RadGrid GridButtonColumn Delete returns 'Object reference not set to an instance of an object'

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Grid

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

Jason Sheats asked on 02 Feb 2012, 05:28 PM

Please note that I do not have a TemplateColumn in my grid to adding a blank ItemTemplate will not work. I read the forums until I am tired of doing it. If I refresh the grid after clearing the IE8 error popup, the record is deleted. I get the prompt, and the record gets deleted, but I simply must know how to get rid of this stupid message.

I'm guessing it's something with databinding, but I have no idea what.

Please help if possible. I appreciate the help in advance.

Jason

Datasource...

<asp:LinqDataSource ID="ldsDeviceToDeviceInfo" runat="server"

ContextTypeName="AssetManagementDataContext" EnableDelete="True"

EnableInsert="True" EnableUpdate="True" EntityTypeName=""

OrderBy="DeviceName, ConnType" TableName="Connections">

</asp:LinqDataSource>

I have this in my RadAjaxManager (among other things not related to this grid):

<telerik:AjaxSetting AjaxControlID="grdDevToDev">

<telerik:AjaxUpdatedControl ControlID="grdDevToDev" LoadingPanelID="RadAjaxLoadingPanel1" />

</UpdatedControls>

</telerik:AjaxSetting>

ASPX RadGrid declaration:

<telerik:RadGrid ID="grdDevToDev" runat="server" EnableLinqExpressions="False" AllowFilteringByColumn="True"

AllowPaging="True" AllowSorting="True" CellSpacing="0"

DataSourceID="ldsDeviceToDeviceInfo" Font-Names="Verdana" Font-Size="8px" GridLines="None"

Skin="WebBlue" Width="90%" AutoGenerateColumns="False"

onitemcommand="grdDevToDev_ItemCommand">

<ClientSettings AllowColumnsReorder="True" AllowKeyboardNavigation="true" ReorderColumnsOnClient="True"

EnablePostBackOnRowClick="false" >

<Selecting AllowRowSelect="True" />

<ClientEvents OnPopUpShowing="PopUpShowing" />

</ClientSettings>

<MasterTableView DataKeyNames="Index" AllowAutomaticDeletes="true"

DataSourceID="ldsDeviceToDeviceInfo" EditMode="Popup" CommandItemDisplay="Top" >

<Columns>

<telerik:GridEditCommandColumn></telerik:GridEditCommandColumn>

<telerik:GridBoundColumn DataField="Index" DataType="System.Int64"

FilterControlAltText="Filter Index column" HeaderText="Index"

ReadOnly="True" SortExpression="Index" UniqueName="Index" Visible="false">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="DeviceName"

FilterControlAltText="Filter DeviceName column" HeaderText="DeviceName"

SortExpression="DeviceName" UniqueName="DeviceName">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="ConnType"

FilterControlAltText="Filter ConnType column" HeaderText="ConnType"

SortExpression="ConnType" UniqueName="ModConnTypeel">

</telerik:GridBoundColumn>

<telerik:GridBoundColumn DataField="CableType"

FilterControlAltText="Filter CableType column" HeaderText="CableType"

SortExpression="CableType" UniqueName="CableType">

<HeaderStyle Width="150px" />

</telerik:GridBoundColumn>

<telerik:GridButtonColumn ConfirmText="Delete this record?" ConfirmDialogType="RadWindow"

ConfirmTitle="Delete" ButtonType="LinkButton" CommandName="Delete" Text="Delete"

UniqueName="DeleteColumn">

<HeaderStyle Width="50" />

<ItemStyle HorizontalAlign="Center" />

</telerik:GridButtonColumn>

</Columns>

<EditFormSettings InsertCaption="Assign/Modify Device to Device Connection" CaptionFormatString="Edit Record: {0}"

CaptionDataField="Index" EditFormType="Template">

<PopUpSettings Modal="True" Width="500px" Height="500px" />

<FormTemplate>

<table id="Table1" cellspacing="0" cellpadding="3" width="450" border="0">

<tr>

<td colspan="3" style="height: 50px">

<asp:ValidationSummary ID="valSummaryNewDevice" ValidationGroup="SaveNewDevice" runat="server"

ForeColor="DarkRed" Width="670px" />

</td>

</tr>

<tr>

<td colspan="3">

<br />

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td style="width: 150px; padding: 1px 2px 1px 2px">

<asp:Label ID="Label3" runat="server" CssClass="formLabel" Height="20px" Text="ID"></asp:Label>

</td>

<td>

<asp:Label ID="tbIndex" Font-Names="Verdana" Font-Size="8pt" runat="server"

Text='<%# Bind("Index") %>' Width="50px" ></asp:Label>

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td style="width: 150px; padding: 1px 2px 1px 2px">

<asp:Label ID="Label6" runat="server" CssClass="formLabel" Height="20px" Text="Device Name"></asp:Label>

</td>

<td>

<asp:TextBox ID="tbAddDeviceName" Width="200px" Text='<%# Bind("DeviceName") %>' Font-Names="verdana" Font-Size="8pt" runat="server"></asp:TextBox>

<asp:RequiredFieldValidator ID="valNewDeviceSubmit" ControlToValidate="tbAddDeviceName"

SetFocusOnError="true" ValidationGroup="SaveNewDevice" Display="Dynamic" ErrorMessage="Missing Device Name"

runat="server">

<img id="Img5" src="~/images/flag_red.png" runat="server" alt="Missing data" /></asp:RequiredFieldValidator>

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td style="width: 150px; padding: 1px 2px 1px 2px">

<asp:Label ID="Label7" runat="server" CssClass="formLabel" Height="20px" Text="Device Type"></asp:Label>

</td>

<td>

<%-- <telerik:RadComboBox ID="rcbAddDeviceType" runat="server" Font-Names="Verdana" Font-Size="8pt" AllowCustomText="true"

MarkFirstMatch="True" NoWrap="True" Skin="Windows7" SortCaseSensitive="False" SelectedValue='<%# Bind("Model") %>'

MaxHeight="250px" Width="200px" DataSourceID="dsDeviceTypes" DataTextField="Device_Type" DataValueField="Device_Type"

AutoPostBack="False" AppendDataBoundItems="true">

<Items>

<telerik:RadComboBoxItem Text="" Value="" />

</Items>

</telerik:RadComboBox>

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" ControlToValidate="rcbAddDeviceType"

SetFocusOnError="true" ValidationGroup="SaveNewDevice" Display="Dynamic" ErrorMessage="Missing Device Type"

runat="server">

<img id="Img1" src="~/images/flag_red.png" runat="server" alt="Missing data" /></asp:RequiredFieldValidator>--%>

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td>

<asp:Label ID="Label8" runat="server" CssClass="formLabel" Height="20px" Text="Cabinet"></asp:Label>

</td>

<td>

<%-- <telerik:RadComboBox ID="rcbAddDeviceCabinet" runat="server" Font-Names="Verdana" AllowCustomText="true"

Font-Size="8pt" MarkFirstMatch="True" NoWrap="True" AutoPostBack="False" Skin="Windows7"

SortCaseSensitive="False" MaxHeight="250px" Width="200px" DataSourceID="dsCabNums" SelectedValue='<%# Bind("Rack") %>'

DataTextField="CabinetNumber" DataValueField="CabinetNumber" AppendDataBoundItems="true" >

<Items>

<telerik:RadComboBoxItem Text="" Value="" />

</Items>

</telerik:RadComboBox>

<asp:RequiredFieldValidator ID="RequiredFieldValidator2" ControlToValidate="rcbAddDeviceCabinet"

SetFocusOnError="true" ValidationGroup="SaveNewDevice" Display="Dynamic" ErrorMessage="Missing Cabinet"

runat="server">

<img id="Img3" src="~/images/flag_red.png" runat="server" alt="Missing data" /></asp:RequiredFieldValidator>--%>

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td style="width: 150px; padding: 1px 2px 1px 2px">

<asp:Label ID="Label9" runat="server" CssClass="formLabel" Height="20px" Text="RU Position"></asp:Label>

</td>

<td>

<%-- <asp:TextBox ID="tbRUPosition" Text='<%# Bind("Rack_Position") %>' Width="200px" Font-Names="verdana" Font-Size="8pt" runat="server"></asp:TextBox><asp:RequiredFieldValidator

ID="RequiredFieldValidator3" ControlToValidate="tbRUPosition" SetFocusOnError="true"

ValidationGroup="SaveNewDevice" Display="Dynamic" ErrorMessage="Missing RU Position"

runat="server">

<img id="Img4" src="~/images/flag_red.png" runat="server" alt="Missing data" /></asp:RequiredFieldValidator>--%>

</td>

</tr>

<tr>

<td style="width: 20px;">

</td>

<td colspan="2">

<%--<hr />--%>

</td>

</tr>

<tr>

<td colspan="3">

<br />

</td>

</tr>

</table>

<table style="width: 100%">

<tr>

<td align="center" colspan="2">

<table>

<tr>

<td>

<telerik:RadButton ID="Button1" ValidationGroup="SaveNewDevice" TabIndex="14" CausesValidation="true"

Text='<%# (Container is GridEditFormInsertItem) ? "Insert" : "Save" %>' runat="server"

Skin="WebBlue" CommandName='<%# (Container is GridEditFormInsertItem) ? "PerformInsert" : "Update" %>'>

</telerik:RadButton>

</td>

<td>

<telerik:RadButton ID="btnCancel" CommandName="Cancel" TabIndex="15" Text="Cancel"

CausesValidation="False" runat="server" Skin="WebBlue">

</telerik:RadButton>

</td>

</table>

</tr>

</td> </tr>

</table>

</FormTemplate>

<EditColumn UniqueName="EditCommandColumn1">

</EditColumn>

<FormTableButtonRowStyle HorizontalAlign="Center" />

</EditFormSettings>

</MasterTableView>

</telerik:RadGrid>

Only method in code-behind for this grid:

protected void grdDevToDev_ItemCommand(object sender, GridCommandEventArgs e)

{

AssetManagementDataContext dc = new AssetManagementDataContext();

if (e.CommandName == RadGrid.DeleteCommandName)

{

var index = (int)((GridDataItem)e.Item).GetDataKeyValue("Index");

//retrieve entity form the Db

var device = dc.Connections.Where(n => n.Index == index).FirstOrDefault();

if (device != null)

{

//add the category for deletion

dc.Connections.DeleteOnSubmit(device);

try

{

//submit chanages to Db

dc.SubmitChanges();

grdAddSwitch.Rebind();

}

catch (System.Exception exc)

{

Response.Write("Error deleting switch.\nError Message: " + exc.Message);

}

3 Answers, 1 is accepted

answered on 25 Sep 2014, 01:53 PM

I also have a problem when deleting from my RadGrid control. I set the Data Source of the RadGrid to a basic EntityDataSource object. AutoGenerateDeleteColunm is True and AllowAutomaticDeletes is True. Everything works fine when the user clicks on the "delete" link. But as soon as I convert one the fields in the grid to a template colunm, the "delete" produces the following error: Object reference not set to an instance of an object. There is no custom event code on this page.

Here is the code:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Test1.aspx.cs" Inherits="PMC.Test1" %>
<%@ Register assembly="Telerik.Web.UI" namespace="Telerik.Web.UI" 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">
<telerik:RadScriptManager ID="RadScriptManager1" runat="server">
<Scripts>
<asp:ScriptReference Assembly="Telerik.Web.UI"
Name="Telerik.Web.UI.Common.Core.js">
</asp:ScriptReference>
<asp:ScriptReference Assembly="Telerik.Web.UI"
Name="Telerik.Web.UI.Common.jQuery.js">
</asp:ScriptReference>
<asp:ScriptReference Assembly="Telerik.Web.UI"
Name="Telerik.Web.UI.Common.jQueryInclude.js">
</asp:ScriptReference>
</Scripts>
</telerik:RadScriptManager>
<div>
<asp:EntityDataSource ID="EntityDataSource1" runat="server"
ConnectionString="name=PMCEntities" DefaultContainerName="PMCEntities"
EnableDelete="True" EnableFlattening="False" EnableInsert="True"
EnableUpdate="True" EntitySetName="PMC_RunMiscParts">
</asp:EntityDataSource>
<telerik:RadGrid ID="RadGrid1" runat="server" AllowAutomaticDeletes="True"
AllowAutomaticInserts="True" AllowAutomaticUpdates="True"
AutoGenerateColumns="False" AutoGenerateDeleteColumn="True"
AutoGenerateEditColumn="True" CellSpacing="0" DataSourceID="EntityDataSource1"
GridLines="None">
<MasterTableView datakeynames="RunMicsPartID" datasourceid="EntityDataSource1">
<CommandItemSettings ExportToPdfText="Export to PDF"></CommandItemSettings>
<RowIndicatorColumn Visible="True" FilterControlAltText="Filter RowIndicator column">
<HeaderStyle Width="20px"></HeaderStyle>
</RowIndicatorColumn>
<ExpandCollapseColumn Visible="True" FilterControlAltText="Filter ExpandColumn column">
<HeaderStyle Width="20px"></HeaderStyle>
</ExpandCollapseColumn>
<Columns>
<telerik:GridBoundColumn DataField="RunMicsPartID" DataType="System.Int32"
FilterControlAltText="Filter RunMicsPartID column" HeaderText="RunMicsPartID"
ReadOnly="True" SortExpression="RunMicsPartID" UniqueName="RunMicsPartID">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="RunID" DataType="System.Int32"
FilterControlAltText="Filter RunID column" HeaderText="RunID"
SortExpression="RunID" UniqueName="RunID">
</telerik:GridBoundColumn>
<telerik:GridTemplateColumn DataField="PartNum"
FilterControlAltText="Filter PartNum column" HeaderText="PartNum"
SortExpression="PartNum" UniqueName="PartNum">
<EditItemTemplate>
<asp:TextBox ID="PartNumTextBox" runat="server" Text='<%# Bind("PartNum") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="PartNumLabel" runat="server" Text='<%# Eval("PartNum") %>'></asp:Label>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridBoundColumn DataField="WorkOrder"
FilterControlAltText="Filter WorkOrder column" HeaderText="WorkOrder"
SortExpression="WorkOrder" UniqueName="WorkOrder">
</telerik:GridBoundColumn>
</Columns>
<EditFormSettings>
<EditColumn FilterControlAltText="Filter EditCommandColumn column"></EditColumn>
</EditFormSettings>
</MasterTableView>
<FilterMenu EnableImageSprites="False"></FilterMenu>
</telerik:RadGrid>
</div>
</form>
</body>
</html>

answered on 30 Sep 2014, 08:18 AM

EntityDataSource.zip

Hello Pat,

I tried to replicate the issue locally by using the following live example but to no avail. I attached the modified sample to this tread, so could you please give it a try and let me know about the result. I would appreciate if you could replicate the issue in my sample or provide a small runnable one in order to investigate it further.

Regards,
Kostadin
Telerik

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