Hello Everyone,

I have a table something like this :

<table style="width: 250px">

<tr>

<td style="width: 100px" id="imageCell" runat="server">

<asp:Image ID="artDayImage" runat="server" Style="border-right: #996600 10px double;

border-top: #996600 10px double; border-left: #996600 10px double; border-bottom: #996600 10px double;"

Width="250px" />



</td>

</tr>

<tr>

<td style="width: 100px; border-right: #996600 thin double; border-top: #996600 thin double;

border-left: #996600 thin double; border-bottom: #996600 thin double; height: 68px;">

<table>

<tr>

<td style="width: 100px">

<asp:Label ID="Label3" runat="server" Text="Title :"></asp:Label></td>

<td style="width: 106px">

<asp:Label ID="titleLabel" runat="server" Text="Mask" Font-Bold="True" Width="177px"></asp:Label></td>

</tr>

<tr>

<td style="width: 100px">

<asp:Label ID="Label6" runat="server" Text="Dimensions :"></asp:Label></td>

<td style="width: 106px">

<asp:Label ID="dimensionLabel" runat="server" Text="11 x 34" Font-Bold="True" Width="178px"></asp:Label></td>

</tr>

<tr>

<td style="width: 100px">

<asp:Label ID="Label8" runat="server" Text="Weight :"></asp:Label></td>

<td style="width: 106px">

<asp:Label ID="weightLabel" runat="server" Text="10 Kg" Font-Bold="True" Width="176px"></asp:Label></td>

</tr>

<tr>

<td style="width: 100px">

<asp:Label ID="Label10" runat="server" Text="Price :"></asp:Label></td>

<td style="width: 106px">

<asp:Label ID="priceLabel" runat="server" Text="20" Font-Bold="True" Width="177px"></asp:Label></td>

</tr>

</table>

</td>

</tr>

<tr>

<td style="border-right: #996600 thin double; border-top: #996600 thin double; border-left: #996600 thin double;

border-bottom: #996600 thin double;" width="250">

<table width="260">

<tr>

<td style="width: 100px">

<asp:ImageButton ID="cartImage" runat="server" AlternateText="Add to my cart" ImageUrl="~/images/site/Add_to_my_cart.gif"

OnClick="cartImage_Click" /></td>

<td style="width: 100px">

 

<asp:ImageButton ID="buyNowImage" AlternateText="Buy now" runat="server" ImageUrl="~/images/site/buynow.gif" /></td>

<td style="width: 100px">

     

<asp:ImageButton ID="wishListImage" AlternateText="Add to Wish list" runat="server"

ImageUrl="~/images/site/Add_to_wish_list.gif" /></td>

</tr>

</table>

</td>

</tr>

</table>

Backend in the code I have something along the lines : It loads first time no problem, but if I call some other page which is based on this mater page

it runs the code below again and that time artImage all the Label are null...I don't know what I'm doing wrong.

if (!IsPostBack)
        {
            /*Update the artwork of the day*/
            Product product = service.GetArtWorkoftheDay();

            /*check if returned result is not null*/
            if (product.ProductType != null)
            {
                /*get the images based on product*/
                Froxion.ArtoAfrica.Objects.Image image = service.GetImagesbyProduct(product);

                if (image.Product != null)
                {
                    /*update the image url*/
                    artDayImage.ImageUrl = image.ThumbnailImage;

                    titleLabel.Text = product.Name;
                    dimensionLabel.Text = product.Dimensions;
                    weightLabel.Text = product.Weight + " Kg";
                    priceLabel.Text = product.Price.ToString();

                    /*Update the link information*/
                    HyperLink link = new HyperLink();
                    link.Attributes.Add("a href", "ShowProduct.aspx?imageLoc=" + image.FullImage + "&productID=" + product.EntityID);
                    link.Attributes.Add("rel", "lyteframe");
                    link.Attributes.Add("title", product.Name);
                    link.Attributes.Add("rev", "width:800px; height:500px;");
                    link.Attributes.Add("scrolling", "no");

                    /*add the image to the link control*/
                    link.Controls.Add(artDayImage);

                    /*add the image to the cell*/
                    imageCell.Controls.Add(link);
                   
                    /*Add the id's to the buttons*/

                    /*Add to Cart Button*/
                    cartImage.CommandName = "Product";
                    cartImage.CommandArgument = product.EntityID.ToString();

                    /*Add to buyNow Button*/
                    buyNowImage.CommandName = "Product";
                    buyNowImage.CommandArgument = product.EntityID.ToString();

                    /*Add to Wish List button*/
                    wishListImage.CommandName = "Product";
                    wishListImage.CommandArgument = product.EntityID.ToString();
                }
            }
}

hi there,,

Please make sure whether the service.GetArtWorkoftheDay() is returns value all the time... or else try by removing the "if with  ispostack condition ".

Srinath

Hello Srinath,

Yes, GetArtWorkoftheDay() function return values all the time and I have tried removing postback and it does the same thing.

Hi,

 Is that works first time it loads...

Yes, it does and have no problem..

thukralz:

but if I call some other page which is based on this mater page

it runs the code below again and that time artImage all the Label are null...

When you redirect to another page which is based on masterpage. the code block in If(!Page.IsPostBack) clause runs again is natural, because when you redirect to another page, it actually redirect to a new page, as master page plays a server control at run time.

You say the artImage and all Label are null at this time. I think I shoud need some more information to help you. would you please provide entire aspx code of master page. Or the structure of  GetArtWorkoftheDay method and service class, which you mentioned at service.GetArtWorkoftheDay(); ? thank you.

This is a lot of code we are talking here....but here it is ....

It works first time fine and the service (artwork just return values even the second time when this thing doesn't work), at the time when all labels and other information is null.....

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="Main.master.cs" Inherits="Theme" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<!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">
    <link href="~/css/AjaxStyles.css" rel="stylesheet" type="text/css" />
    <link href="~/css/Art.css" rel="stylesheet" type="text/css" />
    <link href="~/css/lytebox.css" rel="stylesheet" type="text/css" />
    <title></title>

    <script type="text/javascript" src="js/lytebox.js"></script>

</head>
<body background="images/site/Background_v2_light.jpg">
    <form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <div id="top">
            <div id="top1">
                 </div>
            <div id="top2">
                <a class="links" title="Register" href="AccountCreation.aspx">Register</a> now.
                Already a member? <asp:LoginStatus ID="login" LogoutText="Sign out" LoginText="Sign In"
                    LogoutPageUrl="~/Default.aspx" runat="server" />
            </div>
            <br clear="all">
        </div>
        <div id="search" style="background-color: InactiveBorder">
            <div id="sea1" style="width: 100%">
                <a class="nav" title="Home" href="Default.aspx">Home</a>  |  <a
                    class="nav" title="My Cart" href="secure/User/myaccount.aspx">my account</a>  |  
                <a class="nav" title="About " href="">my cart</a>  |  
                <a class="nav" title="Contact us" href="secure/User/mywishlist.aspx">my wishlist</a>  
            </div>
            <div id="sea2">
                <a class="nav">
                    <asp:Label ID="loginLabel" runat="server" Text=""></asp:Label></a>
            </div>
        </div>
        <table border="0" cellspacing="3" cellpadding="3" style="height: 755px">
            <tr valign="top">
                <td style="width: 100px; height: 747px;">
                    <asp:ContentPlaceHolder ID="LeftContent" runat="server">
                        <div id="tdwidth">
                            <div class="indlef">
                                <asp:ImageButton ID="SculptureImage" runat="server" AlternateText="Exquisite Makonde sculptures from the land of the Maasai- the bushlands of East Africa."
                                    PostBackUrl="~/Sculptures.aspx" ImageUrl="~/images/site/180px-Yoruba-bronze-head.jpg"
                                    Height="235px" Width="196px" />
                                <div class="caption">
                                    <asp:HyperLink ID="SculptureLink" NavigateUrl="~/Sculptures.aspx" runat="server">Sculptures</asp:HyperLink>
                                </div>
                                <asp:ImageButton ID="PaintingImage" runat="server" AlternateText="Works that reflect the lives of the Maasai - the traditional herdsmen and warriors of East Africa."
                                    PostBackUrl="~/Paintings.aspx" ImageUrl="~/images/site/180px-Child-soldier-afrika.jpg"
                                    Height="235px" Width="196px" />
                                <div class="caption">
                                    <asp:HyperLink ID="PaintingLink" NavigateUrl="~/paintings.aspx" runat="server">Paintings</asp:HyperLink>
                                </div>
                            </div>
                            <table style="border-right: lightblue thin solid; border-top: lightblue thin solid;
                                border-left: lightblue thin solid; width: 218px; border-bottom: lightblue thin solid">
                                <tr>
                                    <td style="width: 99px">
                                        <asp:Label ID="Label2" runat="server" Font-Bold="True" Font-Names="Curlz MT" ForeColor="#404040"
                                            Text=".com newsletter" Width="203px" Font-Size="Medium"></asp:Label></td>
                                </tr>
                                <tr>
                                    <td style="width: 99px; height: 21px;">
                                        <table>
                                            <tr>
                                                <td style="width: 100px">
                                                    <asp:TextBox ID="newsletterEmailText" runat="server" Width="150px">Your email address</asp:TextBox></td>
                                                <td style="width: 100px">
                                                    <asp:Button ID="goButton" runat="server" BackColor="Silver" BorderColor="White" BorderStyle="None"
                                                        ForeColor="Blue" Text="GO" Font-Bold="False" /></td>
                                            </tr>
                                        </table>
                                    </td>
                                </tr>
                            </table>
                        </div>
                    </asp:ContentPlaceHolder>
                </td>              
                <td style="width: 100px; height: 747px;">
                    <asp:ContentPlaceHolder ID="MainContent" runat="server">
                        <div class="conpad">
                             </div>
                    </asp:ContentPlaceHolder>
                </td>
                <td style="width: 100px; height: 747px">
                    <asp:ContentPlaceHolder ID="RightContent" runat="server">
                        <div id="cdwidth">
                            <div class="indlef">
                                <div class="caption1">
                                    <asp:Label ID="Label1" runat="server" Text="Artwork of the Day" Width="271px" Font-Bold="True"
                                        Font-Names="Arial" Font-Size="Large" ForeColor="#996600"></asp:Label>
                                    <br />
                                </div>
                                <table style="width: 250px">
                                    <tr>
                                        <td style="width: 100px" id="imageCell" runat="server">
                                            <!-- <a href="ShowProduct.aspx?imageLoc=~/images/Sculptures/Fullsize/Mask_Full.jpg&productID=4"
                                                rel="lyteframe" rev="width:800px; height:575px;" runat="server" id="artLink"> -->
                                            <asp:Image ID="artDayImage" runat="server" Style="border-right: #996600 10px double;
                                                border-top: #996600 10px double; border-left: #996600 10px double; border-bottom: #996600 10px double;"
                                                Width="250px" />
                                            <!-- </a> -->
                                            <!--ImageUrl="~/images/Paintings/Thumbnails/Painting_1.jpg" -->
                                        </td>
                                    </tr>
                                    <tr>
                                        <td style="width: 100px; border-right: #996600 thin double; border-top: #996600 thin double;
                                            border-left: #996600 thin double; border-bottom: #996600 thin double; height: 68px;">
                                            <table>
                                                <tr>
                                                    <td style="width: 100px">
                                                        <asp:Label ID="Label3" runat="server" Text="Title :"></asp:Label></td>
                                                    <td style="width: 106px">
                                                        <asp:Label ID="titleLabel" runat="server" Text="Makonde Mask" Font-Bold="True" Width="177px"></asp:Label></td>
                                                </tr>
                                                <tr>
                                                    <td style="width: 100px">
                                                        <asp:Label ID="Label6" runat="server" Text="Dimensions :"></asp:Label></td>
                                                    <td style="width: 106px">
                                                        <asp:Label ID="dimensionLabel" runat="server" Text="11 x 34" Font-Bold="True" Width="178px"></asp:Label></td>
                                                </tr>
                                                <tr>
                                                    <td style="width: 100px">
                                                        <asp:Label ID="Label8" runat="server" Text="Weight :"></asp:Label></td>
                                                    <td style="width: 106px">
                                                        <asp:Label ID="weightLabel" runat="server" Text="10 Kg" Font-Bold="True" Width="176px"></asp:Label></td>
                                                </tr>
                                                <tr>
                                                    <td style="width: 100px">
                                                        <asp:Label ID="Label10" runat="server" Text="Price :"></asp:Label></td>
                                                    <td style="width: 106px">
                                                        <asp:Label ID="priceLabel" runat="server" Text="USD 200" Font-Bold="True" Width="177px"></asp:Label></td>
                                                </tr>
                                            </table>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td style="border-right: #996600 thin double; border-top: #996600 thin double; border-left: #996600 thin double;
                                            border-bottom: #996600 thin double;" width="250">
                                            <table width="260">
                                                <tr>
                                                    <td style="width: 100px">
                                                        <asp:ImageButton ID="cartImage" runat="server" AlternateText="Add to my cart" ImageUrl="~/images/site/Add_to_my_cart.gif"
                                                            OnClick="cartImage_Click" /></td>
                                                    <td style="width: 100px">
                                                         
                                                        <asp:ImageButton ID="buyNowImage" AlternateText="Buy now" runat="server" ImageUrl="~/images/site/buynow.gif" /></td>
                                                    <td style="width: 100px">
                                                             
                                                        <asp:ImageButton ID="wishListImage" AlternateText="Add to Wish list" runat="server"
                                                            ImageUrl="~/images/site/Add_to_wish_list.gif" /></td>
                                                </tr>
                                            </table>
                                        </td>
                                    </tr>
                                </table>
                            </div>
                        </div>
                    </asp:ContentPlaceHolder>
                </td>
        </table>
        <br />
        <div id="footer">
            <div id="footer1">
                  ? 2007 .com  |   <a class="links"
                    title="Privacy Statement" href="">Privacy Statement</a>  |  
                <a class="links" title="Disclaimer" href="">Disclaimer</a>
            </div>
        </div>
        <br />
        <cc1:ModalPopupExtender ID="loginModalPopupExtender" runat="server" BackgroundCssClass="modalBackground"
            CancelControlID="CancelButton" PopupControlID="LoginViewPanel" TargetControlID="login">
        </cc1:ModalPopupExtender>
        <asp:Panel ID="LoginViewPanel" runat="server" Height="225px" Style="background-color: lavender;
            border-right: moccasin thin solid; border-top: moccasin thin solid; border-left: moccasin thin solid;
            color: mediumblue; border-bottom: moccasin thin solid; text-align: center;" Width="421px">
            <br />
            <asp:Label ID="Label4" runat="server" Text="Please enter Username and Password to procced..."></asp:Label><br />
            <br />
            <asp:Label ID="userorpassIncorrectLabel" runat="server" Text="Username or Password is incorrect."
                Visible="False" ForeColor="#C00000"></asp:Label>
            <table>
                <tr>
                    <td style="width: 100px; height: 26px;">
                        <asp:Label ID="userNameLabel" runat="server" Text="Username :"></asp:Label></td>
                    <td style="width: 100px; height: 26px;">
                        <asp:TextBox ID="userNameTextBox" runat="server"></asp:TextBox></td>
                    <td style="width: 100px; height: 26px;">
                        <asp:RequiredFieldValidator ID="userNameRequiredFieldValidator" runat="server" ControlToValidate="userNameTextBox"
                            ValidationGroup="Login" ErrorMessage="Username is required." Width="135px"></asp:RequiredFieldValidator>
                    </td>
                </tr>
                <cc1:FilteredTextBoxExtender ID="userNameFilteredTextBoxExtender" TargetControlID="userNameTextBox"
                    FilterType="Custom, LowercaseLetters, UppercaseLetters, Numbers" ValidChars="@.-_"
                    runat="server">
                </cc1:FilteredTextBoxExtender>
                <tr>
                    <td style="width: 100px; height: 26px">
                        <asp:Label ID="passwordLabel" runat="server" Text="Password :"></asp:Label></td>
                    <td style="width: 100px; height: 26px">
                        <asp:TextBox ID="passwordTextBox" runat="server" Width="149px" TextMode="Password"></asp:TextBox></td>
                    <td style="width: 100px; height: 26px;">
                        <asp:RequiredFieldValidator ID="passwordRequiredFieldValidator" runat="server" ControlToValidate="passwordTextBox"
                            ValidationGroup="Login" ErrorMessage="Password is required." Width="139px"></asp:RequiredFieldValidator>
                    </td>
                </tr>
                <cc1:FilteredTextBoxExtender ID="FilteredTextBoxExtender1" TargetControlID="userNameTextBox"
                    FilterType="Custom, LowercaseLetters, UppercaseLetters, Numbers" ValidChars="@.-_ "
                    runat="server">
                </cc1:FilteredTextBoxExtender>
            </table>
            <br />
            <asp:Button ID="LoginButton" runat="server" Text="Login" OnClick="LoginButton_Click"
                BackColor="Gray" BorderColor="Olive" ValidationGroup="Login" BorderStyle="None" />
            <asp:Button ID="CancelButton" runat="server" Text="Cancel" BackColor="Gray" BorderColor="Olive"
                BorderStyle="None" /><br />
            <br />
            <asp:HyperLink ID="ForgetUorP" runat="server" Width="202px" Style="background-color: transparent"
                NavigateUrl="~/ForgotUsernameorPassword.aspx">Forgot Username or Password ?</asp:HyperLink><br />
            <asp:HyperLink ID="newAccountHyperLink" runat="server" NavigateUrl="~/AccountCreation.aspx"
                Width="117px">Create an account</asp:HyperLink>
            <br />
        </asp:Panel>
    </form>
</body>
</html>

 // In MastrePage.cs

/*Update the artwork of the day*/

/*check if returned result is not null*/

/*get the images based on product*/

/*update the image url*/

/*Update the link information*/

link.Attributes.Add("a href", "ShowProduct.aspx?imageLoc=" + image.FullImage + "&productID=" + product.EntityID);

link.Attributes.Add("title", product.Name);

link.Attributes.Add("scrolling", "no");

/*add the image to the link control*/

/*add the image to the cell*/

/*Add the id's to the buttons*/

/*Add to Cart Button*/

/*Add to buyNow Button*/

/*Add to Wish List button*/

thukralz:

at the time when all labels and other information is null

I can not debug your code. It looks all right only from the master page and masterpage behind code. I still not very clear which object are null at this time you said. It's the ImageButton or Labels control you declared in Masterpage aspx code? or any data you get from service class using Product product = service.GetArtWorkoftheDay(); and Objects.Image image = service.GetImagesbyProduct(product);?. If it is the later, I think it may be caused by the service class.

It's the ImageButton and the labels are null the second time, there is no problem with service class returning information. All that thing does is go to database and retrieve values and everytime values are returned..

When page loads everything is happy, say I click to go to som other page whic uses this mater page, thats when all these below become null and throw exception.... 

 So, May I have a look at what the exception is? Thanks.

Object reference not set to an instance of an object.

at this exception was raised here : artDayImage.ImageUrl = image.ThumbnailImage;

StackTrace 

"   at Theme.Page_Load(Object sender, EventArgs e) in c:\\Main.master.cs:line 41\r\n   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)\r\n   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)\r\n   at System.Web.UI.Control.OnLoad(EventArgs e)\r\n   at System.Web.UI.Control.LoadRecursive()\r\n   at System.Web.UI.Control.LoadRecursive()\r\n   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)"

Hi,

From your code, we can see, you can put  the table and its controls in the contentpalceholder    

 <asp:ContentPlaceHolder ID="RightContent" runat="server">,

In fact, the contentplaceholder is used to define a region of the master page rendering that can be substituted with content from a page associated to the master.

 A ContentPlaceHolder can also contain default content, just in case the derive page does not need to override this content. Or else, its default content cannot be found at runtime.

 So about your problem, you put the table in the ContentPlaceHolder RightContent, if the content page's content control doesnot map the  ContentPlaceHolder RightContent, it can work fine, If the content control's ContentPlaceHolderID is RightContent, <asp:Content ID="Content3" ContentPlaceHolderID="RightContent" Runat="Server">. so RightContent's region of  the master page will be replaced by content of the content page.

So the artDayImage will cannot be found at runtime, and throw the error message:  Object reference not set to an instance of an object.

And you have a try to put the content of the table out of the ContentPlaceHolder, it wil work fine.

Hope it helps.

It works but it takes the flexibility away of replacing content on wish in different pages. Now whichever page needs that content have to duplicate the code...