Visual Basic 1002005 [A Developers Notebook] [Electronic resources] نسخه متنی

4.1. Create a Web Application in Visual Studio 2005

Visual Studio .NET was the first
product to equip ASP developers with a professional IDE, along with
debugging and syntax-checking tools. However, creating ASP.NET
projects still never seemed quite as easy as creating projects for
ordinary Windows and console applications. Part of the trouble was
managing the interaction between Visual Studio and Internet
Information Services (IIS). Happily, Visual Studio 2005 dramatically
improves the design-time experience for web applications by providing
a new way to work with web projects.

4.1.1. How do I do that?

To create a new web project in Visual Studio 2005 or Visual Studio
Web Developer 2005 (Visual Studio 2005 Express isn't
up to the task), select File
New
Web Site,
not File
New
Project.
You'll see the New Web Site dialog box (see Figure 4-1), in which you need to choose the location
where the web project will be placed, and its development language.
In the future, you'll also be able to open a new
project based on a starter kit from this window.

Figure 4-1. Creating a new web application directory

Note: Forget virtual directories and other IIS headaches. Visual
Studio 2005 (and Visual Web Developer 2005) includes a built-in web
server and supports project-less web sites.

Visual Studio starts you out with a new directory containing two
files:
default.aspx (the
entry point for your web application) and
default.aspx.vb (the code-behind file). There
are no project (.vbproj) or solution
(.sln) files, which keeps the file structure
simpler and makes it easier to deploy just what you need. Instead,
Visual Studio automatically shows all the files and subdirectories in
the web application directory.

Note: When you create a new ASP. NET project, Visual Studio
creates the directory and saves the default web page immediately.
This is different than the behavior you've seen with
other project types, where Visual Studio creates a temporary project
until you explicitly save it.

As you start working with your web application,
you'll find that Visual Studio has a few more
surprises in store. One is the ability to automatically create a
web.config file when
you need it. To try this out, click the Start button to launch your
application for the first time. At this point, Visual Studio notices
that you don't have a
web.config file. It then asks you if
you'd like to add one automatically to enable
debugging (Figure 4-2).

Figure 4-2. Automatically adding a new web.config file

The web.config file that Visual Studio creates
is noticeably cleaner than the automatically generated version in
Visual Studio .NET 2003. It only contains the information you need
(in this case, the debugging settings). As you make other
configuration changes to your application using Visual Studio,
additional sections are added automatically. Once again, Visual
Studio places the emphasis on simplicity and transparency.

When you run your web pages, Visual Studio's
integrated web
server starts automatically (look for a small icon in the system
tray). As a result, you don't need to use IIS to
test a web site. Visual Studio's scaled-down web
server provides better
security because it only serves
requests that originate from the local computer. It also shuts down
once you exit Visual Studio. Best of all, it allows you to create
your web pages and web services where you want them, without worrying
about creating the right virtual directory first.

You can try out all the labs in this chapter using the bare-bones web
application you've created in this lab.

4.1.2. What about...

...the
web page coding model? If you've spent much time
programming ASP.NET web pages, you're probably aware
that there are different ways to separate source code from visual
content. In previous versions of Visual Studio,
code-behind was the only standard that was
supported (which conflicted with the default and exclusive setting of
Web Matrix, another Microsoft web application IDE, which used
inline
code). The happy news is that Visual Studio 2005 supports both of
these code models.

By default, when you add new web pages, Visual Studio 2005 uses a
slightly simpler form of code-behind. Instead of using inheritance,
this updated code-behind relies on another new feature called

partial classes
(see the lab "Split a Class into Multiple
Files" in Chapter 2 for more
information). Because partial classes provide the ability to merge
separate files into one class, the code-behind file you use to handle
web page events doesn't need boilerplate
initialization code and web control declarations. Instead, it
only contains your code, which makes it quite a
bit shorter.

You can also use a code-beside model,
which stores the .aspx tags and the code in the
same file. To insert a new page that uses this model, select Web Site
Add New Item, select Web
Form, and uncheck the "Place code in separate
file" checkbox. Then, click Add to insert the file.
The new file uses the code-beside approach but can be designed and
coded just as easily as a code-behind page.

To support these two models, Visual Studio needed to change its
compilation model for ASP.NET files. Now, web pages and web services
aren't compiled until you access them for the first
time. (In previous versions of Visual Studio, the entire web site is
compiled each time you launch the application by clicking the Start
button.) However, you can still precompile your application after you
deploy it in a production environment to ensure the best performance
for the first set of requests. To do so, just execute a request for
the precompile.axd extension in the root virtual
directory once you deploy your application. For example, if your web
application is stored in the virtual directory named
WebApplication, you would use this URL from the
web server computer:

Note: Don't be distracted by the fact that there
is no file named precompile.axd in your virtual directory. All .axd
requests invoke ASP. NET extensions that are configured in the
machine.config configuration file.

http://localhost/WebApplication/precompile.axd

4.1.3. Where can I learn more?

ASP.NET gives you still more
compilation and deployment options, which you can learn more about
from the whitepaper at http://msdn.microsoft.com/library/en-us/dnvs05/html/codecompilation.asp.