Question

I have install and setup the Asp.net version of AjaxControlToolkit.

version 4.1.5

.Net 4.0

VS 2010

I’m trying to uses the AjaxControlToolkit.MaskedEditExtender Ajax control.
I have setup up a DetailView and some custom Templates that will allow me access to the TextBoxs.

But keep getting this error :

>     Object reference not set to an instance of an object.
>     Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more
> information about the error and where it originated in the code.
>     
>     Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
>     
>     Source Error:
>     
>         An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location
> of the exception can be identified using the exception stack trace
> below.
>         
>         Stack Trace:
>         
>         [NullReferenceException: Object reference not set to an instance of an object.]
>            AjaxControlToolkit.MaskedEditExtender.OnLoad(EventArgs e) in
> C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditExtender.cs:95
>            System.Web.UI.Control.LoadRecursive() +74
>            System.Web.UI.Control.LoadRecursive() +146
>            System.Web.UI.Control.LoadRecursive() +146
>            System.Web.UI.Control.LoadRecursive() +146
>            System.Web.UI.Control.LoadRecursive() +146
>            System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
> +2207

Here is my code for that section(HTML page .ASPX)

<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="New.aspx.cs" Inherits="AequorPubTracker.Account.WebForm1" %>
<asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    &nbsp;Search:
    <asp:TextBox ID="SearchTextBox" runat="server"></asp:TextBox>
&nbsp;
    <asp:Button ID="Button1" runat="server" Text="Search" />
    <asp:DetailsView ID="DetailsView1" runat="server" AllowPaging="True" 
        AutoGenerateRows="False" DataKeyNames="Id" DataSourceID="LinqDataSource1" 
        Height="50px" onpageindexchanging="DetailsView1_PageIndexChanging" 
        style="margin-top: 20px" Width="472px">
        <Fields>
            <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" 
                ReadOnly="True" SortExpression="Id" />
            <asp:TemplateField>
                <EditItemTemplate>
                    <asp:TextBox ID="TextBox1" runat="server" Text='<%# BIND("PubId") %>'></asp:TextBox>

                </EditItemTemplate>
                <InsertItemTemplate>
                    <asp:TextBox ID="TextBox2" runat="server" Text='<%# BIND("PubID") %>'></asp:TextBox>
                </InsertItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="Label2" runat="server" Text='<%# Eval("PubId") %>'></asp:Label>
                    <br />
                    <asp:Label ID="Label3" runat="server" Text='<%# Eval("Sent_from_naylor") %>'></asp:Label>
                    <br />
                    <asp:Label ID="Label4" runat="server" Text='<%# Eval("RecByAequorMgt") %>'></asp:Label>
                    <br />
                    <asp:Label ID="Label5" runat="server" Text='<%# Eval("AssignedToAequorRes") %>'></asp:Label>
                    <br />
                    <asp:Label ID="Label6" runat="server" Text='<%# Eval("SentTonaylor") %>'></asp:Label>
                    <br />
                    <asp:Label ID="Label7" runat="server" Text='<%# Eval("Status") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:CommandField ShowEditButton="True" ShowInsertButton="True" />
        </Fields>
    </asp:DetailsView>

   <ajaxToolkit:MaskedEditExtender ID="MaskedEditExtender1" runat="server"  
     TargetControlID="TextBox1"   
     Mask="999,9999"  
     MessageValidatorTip="true"   
     OnFocusCssClass="MaskedEditFocus"   
     OnInvalidCssClass="MaskedEditError"  
     MaskType="Number"   
     InputDirection="RightToLeft"   
     AcceptNegative="Left"   
     DisplayMoney="Left"  
     ErrorTooltipEnabled="True"/>


   <ajaxToolkit:MaskedEditExtender ID="MaskedEditExtender2" runat="server"  
     TargetControlID="TextBox2"   
     Mask="999,9999"  
     MessageValidatorTip="true"   
     OnFocusCssClass="MaskedEditFocus"   
     OnInvalidCssClass="MaskedEditError"  
     MaskType="Number"   
     InputDirection="RightToLeft"   
     AcceptNegative="Left"   
     DisplayMoney="Left"  
     ErrorTooltipEnabled="True"/>

    <asp:LinqDataSource ID="LinqDataSource1" runat="server" 
        ContextTypeName="AequorPubTracker.AequorDataDataContext" EnableDelete="True" 
        EnableInsert="True" EnableUpdate="True" EntityTypeName="" 
        TableName="Aequor_Pub_Trackers">
    </asp:LinqDataSource>

    <asp:QueryExtender ID="QueryExtender1" runat="server" TargetControlID="LinqDataSource1">

    <asp:SearchExpression SearchType="StartsWith" DataFields="PubId">
      <asp:ControlParameter ControlID="SearchTextBox" />
     </asp:SearchExpression>

    </asp:QueryExtender>
&nbsp;

</asp:Content>

Answer 1

You’re receiving this error becase the target control is nested in a databound control, and the extender is unable to find the target control. Try putting the MaskedEditExtender in the DetailsView control.