Code Behind vs. no code behind: error

[Ben Miller [msft]]

I believe that you will need to Inherit the StoreComponents.ProductTemplate
into the class for the codebehind for the usercontrol.

So in the definition of the class:
in C#

public abstract class UsersUserControl : StoreComponents.ProductTemplate
{

stuff....

}

That way the UserControl has access to the ProductName property of the class
because it inherited it, not imported it. I would have done it with the
Inherits StoreComponents.ProductTemplate but I was not sure how a
UserControl code-behind looked in VB as I do all my work in C#.

HTH.

Ben Miller

--
This posting is provided "AS IS" with no warranties, and confers no rights.


"Alphonse Giambrone" <NOSPAMagiam@customdatasolutions.us> wrote in message
news:uUiqbBcODHA.1584@TK2MSFTNGP11.phx.gbl...

> I am in the final chapter of the book ASP.NET Unleashed which is building

an

> online store. All examples in the book were written without using
> code-behind, but I am using Visual Studio.Net.
> Throughout the book I have been able to get everything to work using
> code-behind with relatively minor modifications.
> I have run into a problem with this project dynamically loading a user
> control.
>
> The code in the book for the user control is as follows:
>
> <%@ Inherits="StoreComponents.ProductTemplate" %>
>
> <font size="8" color="DarkRed"><%= ProductName %></font>
> <p>
> <font size="5"><%= UnitPrice.ToString( "c" ) %></font>
>
> Since I am using VS.NET, I created a new user control and added the
> following in html:
> <font size="8" color="DarkRed"><%= ProductName %></font>
> <p>
> <font size="5"><%= UnitPrice.ToString( "c" ) %></font>
>
> In the code-behind I added:
> Imports StoreComponents.ProductTemplate
>
> The error I get is: Name 'ProductName' is not declared
>
> If I create the file in notepad without code-behind (as in the first
> listing),
> it works fine.
>
> There is a product template class which is compiled in StoreComponents.dll
> as follows:
>
> Public Class ProductTemplate
> Inherits UserControl
> Public ReadOnly Property ProductID() As Integer
> Get
> Return Context.Items("ProductID")
> End Get
> End Property
>
> Public ReadOnly Property ProductName() As String
> Get
> Return Context.Items("ProductName")
> End Get
> End Property
>
> Public ReadOnly Property UnitPrice() As Decimal
> Get
> Return Context.Items("UnitPrice")
> End Get
> End Property
>
> Public ReadOnly Property Product() As DataRowView
> Get
> Return Context.Items("ProductInfo")
> End Get
> End Property
> End Class
>
> I can leave that file without code-behind, but would really like to
> understand what needs to be done to use the code-behind.
> Any help would be appreciated.
>
> --
>
> Alphonse Giambrone
> Email: [email]NOSPAM@customdatasolutions.us[/email]
> For email replace NOSPAM with agiam
>
>
>

[Alphonse Giambrone]

Thanks for the reply, Ben. You are correct.
The vb code-behind for a user control normally has the line
Inherits System.Web.UI.UserControl

I changed to

Inherits StoreComponents.ProductTemplate

The project builds and runs. The only problem is that I get an error when
opening the ascx file in the VS IDE:
The file failed to load in the Web From Designer. Please correct the
following error, then load it again: Property accessor " Product' on object
'Default' threw the following exception: 'Object reference not set to an
instance of an object.'

Thanks again for your help!

--

Alphonse Giambrone
Email: [email]NOSPAM@customdatasolutions.us[/email]
For email replace NOSPAM with agiam


"Ben Miller [msft]" <benmi@online.microsoft.com> wrote in message
news:uJ6DgrMPDHA.1720@TK2MSFTNGP11.phx.gbl...

> I believe that you will need to Inherit the

StoreComponents.ProductTemplate

> into the class for the codebehind for the usercontrol.
>
> So in the definition of the class:
> in C#
>
> public abstract class UsersUserControl : StoreComponents.ProductTemplate
> {
>
> stuff....
>
> }
>
> That way the UserControl has access to the ProductName property of the

class

> because it inherited it, not imported it. I would have done it with the
> Inherits StoreComponents.ProductTemplate but I was not sure how a
> UserControl code-behind looked in VB as I do all my work in C#.
>
> HTH.
>
> Ben Miller
>
> --
> This posting is provided "AS IS" with no warranties, and confers no

rights.

>
>
> "Alphonse Giambrone" <NOSPAMagiam@customdatasolutions.us> wrote in message
> news:uUiqbBcODHA.1584@TK2MSFTNGP11.phx.gbl...

> > I am in the final chapter of the book ASP.NET Unleashed which is

building

> an

> > online store. All examples in the book were written without using
> > code-behind, but I am using Visual Studio.Net.
> > Throughout the book I have been able to get everything to work using
> > code-behind with relatively minor modifications.
> > I have run into a problem with this project dynamically loading a user
> > control.
> >
> > The code in the book for the user control is as follows:
> >
> > <%@ Inherits="StoreComponents.ProductTemplate" %>
> >
> > <font size="8" color="DarkRed"><%= ProductName %></font>
> > <p>
> > <font size="5"><%= UnitPrice.ToString( "c" ) %></font>
> >
> > Since I am using VS.NET, I created a new user control and added the
> > following in html:
> > <font size="8" color="DarkRed"><%= ProductName %></font>
> > <p>
> > <font size="5"><%= UnitPrice.ToString( "c" ) %></font>
> >
> > In the code-behind I added:
> > Imports StoreComponents.ProductTemplate
> >
> > The error I get is: Name 'ProductName' is not declared
> >
> > If I create the file in notepad without code-behind (as in the first
> > listing),
> > it works fine.
> >
> > There is a product template class which is compiled in

StoreComponents.dll

> > as follows:
> >
> > Public Class ProductTemplate
> > Inherits UserControl
> > Public ReadOnly Property ProductID() As Integer
> > Get
> > Return Context.Items("ProductID")
> > End Get
> > End Property
> >
> > Public ReadOnly Property ProductName() As String
> > Get
> > Return Context.Items("ProductName")
> > End Get
> > End Property
> >
> > Public ReadOnly Property UnitPrice() As Decimal
> > Get
> > Return Context.Items("UnitPrice")
> > End Get
> > End Property
> >
> > Public ReadOnly Property Product() As DataRowView
> > Get
> > Return Context.Items("ProductInfo")
> > End Get
> > End Property
> > End Class
> >
> > I can leave that file without code-behind, but would really like to
> > understand what needs to be done to use the code-behind.
> > Any help would be appreciated.
> >
> > --
> >
> > Alphonse Giambrone
> > Email: [email]NOSPAM@customdatasolutions.us[/email]
> > For email replace NOSPAM with agiam
> >
> >
> >

>
>