Frustrating, I can't think offhand why the cast is invalid either. A
quick workaround is to specify the property of the control when it is
being parsed instead of trying to cast to set the property as an object:
System.Web.UI.Control myForm = Page.FindControl("WebForm1");
System.Web.UI.Control ctl = Page.ParseControl("<asp:Button
runat=\"server\" id=\"test\" text=\"Hello, World!\"/>");
myForm.Controls.Add(ctl);
Kirk Allen Evans
http://www.xmlandasp.net
Author, "XML And ASP.NET", New Riders Publishing
http://www.amazon.com/exec/obidos/ASIN/073571200X
> -----Original Message-----
> From: Moderated discussion of advanced .NET topics. [mailto:ADVANCED-
> [EMAIL PROTECTED]] On Behalf Of Steven Livingstone
> Sent: Tuesday, September 17, 2002 1:59 PM
> To: [EMAIL PROTECTED]
> Subject: Re: [ADVANCED-DOTNET] Controls, .Net and Xslt insanity
>
> Ok, what is wrong with this example from the SDK? Invalid Cast
exception
> at the line marked ***. Do you have a working example or a pointer to
> one :)
>
> <%@ Page language="c#" %>
> <html>
> <head>
> <script language="C#" runat="server">
> void Page_Load(object sender, System.EventArgs
> e)
> {
> Button myButton =
> (Button)ParseControl("<asp:button runat = \"server\"/>"); //***
> myButton.Text = "Hello World!";
> Controls.Add(myButton);
> }
>
> private void button_OnClick(object sender,
> System.EventArgs e)
> {
> }
> </script>
> </head>
> </html>
>
> -----Original Message-----
> From: Moderated discussion of advanced .NET topics.
> [mailto:[EMAIL PROTECTED]] On Behalf Of Kirk Allen
> Evans
> Sent: 17 September 2002 18:51
> To: [EMAIL PROTECTED]
> Subject: Re: [ADVANCED-DOTNET] Controls, .Net and Xslt insanity
>
>
> No, it is a string. Retrieve your output from the transformation as a
> string, and parsecontrol can load that string in. The example in the
> SDK is actually a good representation of how to do it, since it is
> simple. The key is to get the XSLT out as a string so that it can be
> loaded into Page.ParseControl.
>
> Remember to either have a form element declared in the .ASPX page and
> add controls to it, or dynamically add it and use Page.Controls.Add
> method to add the form and its child controls.
>
> Kirk Allen Evans
> http://www.xmlandasp.net
> Author, "XML And ASP.NET", New Riders Publishing
> http://www.amazon.com/exec/obidos/ASIN/073571200X
>
> > -----Original Message-----
> > From: Moderated discussion of advanced .NET topics.
[mailto:ADVANCED-
> > [EMAIL PROTECTED]] On Behalf Of Steven Livingstone
> > Sent: Tuesday, September 17, 2002 1:28 PM
> > To: [EMAIL PROTECTED]
> > Subject: Re: [ADVANCED-DOTNET] Controls, .Net and Xslt insanity
> >
> > Hi Kirk -
> > Yep - that is exactly the way I want to do it. Any good examples of
> > working with the ParseControl? The MSDN ones fail with a cast
> exception.
> > The LoadControl() would be cool if it took a MemoryStream - but it
> > doesn't :(
> >
> > I think that if Xslt was better integrated with the IDE we could
have
> > pretty powerful server controls. I've stayed away from server
> > controls, but now I am finding the fun in trying to work with them
> > with the Xslt knowledge I have.
> >
> > Thanks,
> > Steven
> >
> > -----Original Message-----
> > From: Moderated discussion of advanced .NET topics.
> > [mailto:[EMAIL PROTECTED]] On Behalf Of Kirk Allen
> > Evans
> > Sent: 17 September 2002 18:01
> > To: [EMAIL PROTECTED]
> > Subject: Re: [ADVANCED-DOTNET] Controls, .Net and Xslt insanity
> >
> >
> > One way to do this is to use the Page.ParseControl and Controls.Add
> > methods to load the controls that are dynamically created. The
> downside
> > to the approach is that the web forms controls are prefixed with
> "asp:",
> > but the page has no namespace declaration associated with the
> namespace
> > prefix "asp". So, you have to fake one in your XSLT, then remove it
> so
> > that Page.ParseControl doesn't throw an exception. So, you have to
> > implement some sort of a post-processor on your XSLT result as a
> string
> > to remove the xmlns declaration for the dummy namespace bound to the
> asp
> > prefix, but leaving the asp prefix on all nodes. Or, you can output
> > elements as HTML with an additional "runat='server'" attribute and
> pass
> > them into the Page.ParseControl method, enabling them to become HTML
> > server controls. Performance takes a hit, but I couldn't pinpoint
any
>
> > huge glaring performance issues with small test sets.
> >
> > Personally, I prefer a mixed approach, using XML to load into
DataSets
>
> > that are bound to UI elements as well as to use XSLT for limited
> display
> > areas instead of entire pages.
> >
> > Kirk Allen Evans
> > http://www.xmlandasp.net
> > Author, "XML And ASP.NET", New Riders Publishing
> > http://www.amazon.com/exec/obidos/ASIN/073571200X
> >
> > > -----Original Message-----
> > > From: Moderated discussion of advanced .NET topics.
> [mailto:ADVANCED-
> > > [EMAIL PROTECTED]] On Behalf Of Steven Livingstone
> > > Sent: Tuesday, September 17, 2002 12:02 PM
> > > To: [EMAIL PROTECTED]
> > > Subject: [ADVANCED-DOTNET] Controls, .Net and Xslt insanity
> > >
> > > Ok, even after taking time out again to think about this issue I
> feel
> > I
> > > need some view and opinions.
> > > Creating web controls in .Net - when and how?
> > >
> > > For years now I have almost without exception used Xslt to
generate
> > the
> > > output for forms and content alike. Now, with web controls there
is
> > the
> > > mixed content and code, some of which I don't like all that much.
To
>
> > > generate a menu for example, I would be more tempted to write the
> code
> >
> > > to use Xslt to transform the data. The idea of writing out table
> > > elements in C# code with javascript inserted as strings is not at
> all
> > > appealing.
> > >
> > > When it comes to forms, it is more appealing as you can get state
> > > management and validation - both of which are a pain to manage in
> > Xslt.
> > > Still you have the annoying need to write out table elements and
> form
> > > elements (e.g. output.Write("<td class='clsMenuBarCell'
nowrap>");)
> > >
> > > I have hit one of those mind block days where I am arguing with
> myself
> >
> > > over the better way to do things, so it's out to the jury to let
me
> > know
> > > what you have been doing.
> > > I'm pretty sure the best way is some combination - this would
> ideally
> > be
> > > a way of still getting state management and validation, with OO,
but
>
> > > being able to separate the display from the Asp.Net, but this
> doesn't
> > > seem possible.
> > >
> > > I also dislike the idea of transforming to an aspx page and then
> > loading
> > > that.
> > >
> > > Has anyone looked at in memory dynamic compilation? In other
words,
> > > still having your xslt's that can be loaded. These transform to an
> > aspx
> > > output in memory that is dynamically returned so that you can
still
> > get
> > > all the benefits of state management and validation methods? An
> > example
> > > may be:
> > >
> > > - user vists page
> > > - aspx page generates form using Xml data and Xslt to create aspx
> code
> > > - user submits data
> > > - aspx code behind validates and maintains viewstate
> > > - in memory aspx output section is modified by code-behind (e.g.
> > > label.Text="Invalid Telephone Number")
> > > - result is sent to the output
> > >
> > > Thanks,
> > > Steven.
> > >
> > >
> > > ==========================================================
> > > Steven Livingstone BSc (hons), PgDip ITS
> > [[EMAIL PROTECTED]]
> > > .Net & Xml Consultant
> > >
> > > Change your business at http://www.deltabis.net
> > > Grow your business at http://www.venturetogether.com
> > > Change European Football at http://www.theatlanticleague.com
> > >
> > > *** Author of "Application Development with MSXML 4.0"
> > > *** Coming Soon to a developer near you...
> > > "Beg VB.NET XML:Essential XML Skills for VB.NET Programmers" "Beg
C#
>
> > > XML:Essential XML Skills for C# Programmers"
> > > ==========================================================
> > >
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