ASP:Object reference not set to an instance of an object

Question

i am trying to pass a value to a label from a data source, but it keeps on giving me this error.

form1.aspx:

 <asp:FormView ID="ProductsView" DataSourceID="ProductDataSource" DataKeyNames="Parking_ID"
                runat="server" >
                <ItemTemplate>
                    <div style="width: 200px; height: 200px; border: solid 10px white; background-position: center;
                        background-repeat: no-repeat; background-image: url('<%# Eval("Parking_ID", "images/{0}.bmp") %>');">
                    </div>
                    <asp:HiddenField Value='<%# Eval("Parking_Cost") %>' ID="hiddenPrice" runat="server" />
                    <asp:HiddenField Value='<%# Eval("Parking_Name") %>' ID="hiddenName" runat="server" />
                    <asp:HiddenField Value='<%# Eval("Parking_ID") %>' ID="HiddenField1" runat="server" />
                </ItemTemplate>
            </asp:FormView>
             <asp:Label ID="lblName" runat="server" Text="TEST" CssClass="title" Style="font-size: 17px;
                display: block;"></asp:Label>
            <asp:Label ID="lblPrice" runat="server" Text="TEST" CssClass="title" Style="color: Red;
                font-size: 12px;"></asp:Label>
                <asp:Label ID="lbl_ID" runat="server" Text="" CssClass="title" Style="color: Red;
                font-size: 12px;"></asp:Label>
                <asp:SqlDataSource ID="ProductDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:mydatabaseConnectionString2 %>"
    ProviderName="System.Data.SqlClient" SelectCommand="SELECT * FROM [Parking] WHERE ([Parking_ID] = @Parking_ID)">
    <SelectParameters>
        <asp:Parameter Name="Parking_ID" Type="Int32" />
    </SelectParameters>
</asp:SqlDataSource>

form1.aspx.vb:

lblName.Text = DirectCast(Me.ProductsView.FindControl("hiddenName"), HiddenField).Value

I am using vb.net script

Any ideas ?

Regards.

possible duplicate of What is a NullReferenceException in .NET? — John Saunders
– John Saunders, Commented May 1, 2011 at 22:30

Bala R · Accepted Answer · 2011-05-01 22:26:12Z

1

The Controls are usually in the data row of the FormView.

Try

lblName.Text = DirectCast(Me.ProductsView.Row.FindControl("hiddenName"), HiddenField).Value

But in general, when you use Control.FindControl(), there is a chance it will return Nothing if it cannot find it. So the best thing to do is do a TryCast instead of DirectCast and check to see if it's Nothing.

edited May 1, 2011 at 22:26

answered May 1, 2011 at 22:19

Bala R

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Comments

Akram Shahda · Accepted Answer · 2011-05-01 22:18:17Z

1

I guess the error source is the following statement:

Me.ProductsView.FindControl("hiddenName")

And the reason is that you dont have a Control with the ID of "hiddenName" directly in the ProductsView control.

You may need to use a recursive function to get the control ..

answered May 1, 2011 at 22:18

Akram Shahda

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Comments

BrunoLM · Accepted Answer · 2011-05-01 22:23:38Z

0

Is this code in the bind event?

lblName.Text = DirectCast(Me.ProductsView.FindControl("hiddenName"), HiddenField).Value

If so, it might be that you have to check which template it is running:

if (e.Item.ItemType == ItemType || e.Item.ItemType == AlternateItemType)

^{(I'm not sure of the types for FormView, but in a GridView it would be like this.}

The control hiddenName doesn't existing on other templates.

Also you have to find the control from e.Item which is the current template.

answered May 1, 2011 at 22:23

BrunoLM

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