I am using Visual Studio 2010 on a window 7 and Server 2008 and I am editing html pages that are not part of a solution or project. For over a year I have had the same problem when I load a .html page for editing the whole page has squiggly lines and errors. There are two specific errors.
unrecognized tag prefix or device filter 'vslawNet' //this is a custom namespace class I can deal with this error. unrecognized tag prefix or device filter 'asp' this is the one that is all over the page not a single .NET control is immune.
Because these pages are not part of a Visual Studio Solution we use the following page declarations. <%@ Page Language="C#" Debug="false" Src="~/components/service/viewSubscriptions.cs" autoeventwireup="True" Inherits="vslAdmin.ViewSubscriptions" %>
This particular page uses a code behind as indicated by the Src attribute of the Page element. There are no errors in the code behind; but intellisense doesn't work at all.
The pages have been in production for many years (12) and were original created in Visual Studio 6 and have been edited in various versions of Visual Studio with no problem until now. In fact the previous version 2008 (I think) was the version I used to fix all the bad html. So it seems ridiculous that this version of Visual Studio would suddenly not recognize .net controls. I have looked at the editor options until I am blue in the face with nothing pointing to the problem. Understand that intellisense doesn't work either and it used to in the earlier versions of Visual Studio (.net not 6). I am not a big fan of intellisense; but at times it is handy to have when I forget a property method signature. Of course when I turn off validation; by deselecting show errors then I don't even see the normal html errors. I read somewhere that the build configuration might be the culprit; but the setting they referred to does not apply to Web pages.
Is there a add-on that is supposed to be installed? Which seems a little stupid since .NET is the main platform; but I need to ask the question. I would like to convert the web site to a Visual Studio solution (assuming that will solve the problem); but I don't have the resources for a project of that magnitude. I have three web sites with hundreds of complex pages and I am the only .NET developer in the company so you see the problem.
I have tried using Visual Studio Express and while it doesn't have the validation errors it also doesn't provide intellisense for asp elements or code behind objects.
Thanks in advance for any answer you may provide.
Pamela Reinskou