How to convert ASP.NET website to ASP.NET web application - asp.net

Question

I have an ASP.NET 3.5 Website (visual studio lingo), but the site continues to grow and is looking rather cowboyish among other things. I'd like to see this get converted into a Web Application (namespaces and all).
Is this something that can be easily done in Visual Studio? If not, are there any other tools out there that could create all of the namespaces, etc. automagically?

Answer 1

Well, it turns out that the option "Convert to web application" does NOT exist for "websites". The option "Convert to web application" does exist only for "web applications" !!!!
[emphasis mine]
So, here's the deal, to do the
conversion, you need to:
Add a new "Web Application" to your VS 2008 solution (File->Add->New
Project->C#->Web->ASP.NET Web
Application).
Afterwards, you copy all the files in the old "website" to your newly
created "web application", and
override any files created in it by
default
The next step is the most ugly, you need to "manually" add the references
in your "website" to the new "web
application". I thought the VS 2008
PowerCommands toy would do this for me
as it does copy references from other
project types, but it didn't. You have
to do it by yourself, manually, and
you have to be cautious in this step
if you have multiple versions of the
same assembly (like AJAXToolkit in my
case) or assemblies that have both GAC
and local versions or so.
Keep repeating the last step and trying to build the "web application".
You'll keep getting errors like "
'....' is unknown namespace. Are you
missing an assembly reference? ". Make
sure you have none of those except the
ones where '....' is replaced by the
IDs of the server controls you use. In
other words, keep adding references
and building the project until only
the errors that exist because of
missing .DESIGNER.CS or .DESIGNER.VB
files.
Afterwards, go to the "web application" root project node in VS
2008 solution explorer, and right
click it, then you WILL find the
option "Convert to web application".
What this option does is actually
making small changes to the "#Page"
and "#Control" directives of pages and
controls, and creating the required
.DESIGNER.CS or .DESIGNER.VB files.
Try building the "web application" again. If you get errors, see what
references may be missing and/or go
click the "Convert to web application"
again. Sometimes, if there's any error
other than those caused of missing
DESIGNER files, not all the
pages/controls will have those
DESIGNER files created for them.
Fixing the non DESIGNER problem and
clicking "Convert to web application"
again should do the job for this.
Once you are done successful VS build, you should be ready to go.
Start testing your web application.
Optionally, you can right click the
"web application" root project node in
VS 2008 Solution Explorer and click
"Properties" then go to the tab "Web"
to set the "web application" to a
virtual folder in IIS (you can create
new virtual directory from there in
VS). If you want to use the IIS
virtual directory that the old
"website" used, you need to remove
that from IIS first.
Update: When testing your pages, pay MOST ATTENTION to classes in
"App_Code" folder, especially those
with NO NAMESPACE. Those can be a big
trap. We had a problem with two
extension method overloads in the same
static class that had no namespace,one
extends DateTime? (Nullable)
and calls another overload that
extends DateTime itself. Calling the
other overload as extension method
passed VS 2008 compilation and gave us
a compilation error ONLY IN RUNTIME
(With IIS). Changing the call to the
other overload from calling it as
extension method to calling it as
normal static method (only changing
the call in the same class, calls from
other classes remained extension
method calls) did solve this one, but
clearly, it's not as safe as it used
to be in VS 2005. Especially with
classes with no namespaces.
Update2: During the conversion, VS 2008 renames your "App_Code" to
"Old_App_Code". This new name sounds
ugly, but DO NOT RENAME IT BACK. In
the "web application" model, all code
will be in one assembly. In runtime,
the web server does not know what web
project type you are using. It does
take all code in "App_Code" folder and
create a new assembly for it. This
way, if you have code in folder named
"App_Code", you'll end up with RUNTIME
compilation errors that the same types
exist in two assemblies, the one
created by VS, and the one created by
IIS / ASP.NET Development Server. To
avoid that. leave the "Old_App_Code"
with the same name, or rename it to
ANYTHING EXCEPT: "App_Code". Do not
place any code in such "App_Code"
folder and prefereably do NOT have a
folder with such name in your "web
application" at all.
I know this since before but forgot it
now as I have not used "website" model
for long :(.

Answer 2

Walkthrough: Converting a Web Site Project to a Web Application Project in Visual Studio at MSDN
If your website application grows.. it's better to split it into several projects. Conversion from Web Site project to Web Application project won't help much.

Answer 3

If you're having problems getting your new Web Application Project to build check the File Properties in Visual Studio of all 'helper' classes. For a project I was converting the Build Action was set to Content whereas it should have been Compile.

Answer 4

I've now successfully migrated one Website project to a web application and there is quiet a few gotchas to look out for.
Having ReSharper at your disposal helps a lot in refactoring the aspx files.
Set up your solution and create an empty WebApplication
Copy all file over
aspx files in website projects don't have a namspace. Wrap your classes in the appropriate namespaces
During copying, all my pages in subfolders got renamed to my project name and the foldername, so I got 40ish public partial class FolderName_Projectname : Page If neccessary rename all files using Resharper or manually.
If you encounter multiple errors like "There is already a member Page_Load() defined", this is most likely due to incorrect class names und duplication
After adding a namespace
Replace CodeFile in all aspx pages with Codebehind and especially pay attention to files i your subfolder. Make sure Inhertis="" doesn't contain the relative path. Your namespaces take care of everything. So the correct format is Inherits="Namespace.classname".
If your class has a namespace NaSpa and a filename foo.cs it would be Inherits="NaSpa.foo"
After you have prepared all your files (don't forget your master pages), run "Convert to web application". If you encounter errors afterwards, rinse and repeat.
If you encounter errors of the sort "TextBoxName can't be found are you missing a reference", make sure you did not forget to sanitize your aspx pages. A good indicator is to check the automatically generated designer files. If TextBoxName does not appear in there, the conversion did not succeed completely.
Resolve any missing dependencies.
Build

Answer 5

Create a New Web Application in VS 2010.
1. Using Windows Explorer copy all your files into you project folder.
2. In VS 2010 solution explorer show all files.
3. Select the files and folders - right click include in project.
4. Right click the project solution explorer and select Convert to Web Application.
There are quite a few small differences, such as the App_Code folder will get renamed to old_app_code - that surprisingly doesn't cause any errors. The TypeName on your object data sources and the inherits on the #Page tag might need the [ProjectName]. prefix appended globally. For example if your type name was "BusinessLogic.OrderManager" and your project name is InventorySystem you would need to change it to InventorySystem.BusinessLogic.OrderManager. Also a few display changes, such as required field validators don't default to red font anymore, they default to black.

Answer 6

I was facing the same problems initially. After following the Wrox Professional ASP.NET 4.0 book, I found the following solution for my case.
I first created a new web application. Copied all the website files into the web application folder. Right click on the application, and click conver to web application.
You might ask why you need to convert a web app into a web app. The answer is, that when you create a website, you simply code the .cs file where-ever required.
A web application, however declares .design.cs (or .vb) and a .cs file for the code and design section automatically.
NEXT: Remove all manual references, like 'Inherits' attribute in the PAGE directive, to other files in your website, since name spaces WILL take care of referencing the classes centrally.
I also faced a problem, since I had not included OBJ and BIN folder in my project.
If you think you are missing your BIN and OBJ folders, simply click the 'Show All Files' icon in the Solution Explorer and then right click on the missing folders and add to project. (to make sure they compile with the project.)
UPDATE:
As #deadlychambers points out in the comments: You can search everywhere by doing a "Ctrl + Shift + F" and then search for Inherits="(.*?)". This will find all occurrences and probably save you some time!

Answer 7

the default ASP name space does not seem to work anymore. So I cannot seem to call my User Controls.ascx pages from outside the page. Giving them a namespace and changing the default from ASP to my namespace seemed to work.