ASP.NET 2.0: A Developeramp;#039;s Notebook [Electronic resources] نسخه متنی

1.1. Create a New Web Project

The way you create a new web
application project has changed
in Visual Studio 2005. In Visual Studio .NET 2003, you select
File New Project on the
Visual Studio menu and then select the kind of project you want to
create (Web, Windows, Windows Services, and so on) in the New Project
Dialog. In Visual Studio 2005, you open a new web project with the
New Web Site... command in the File menu.

Visual Studio 2005 Editor Settings

When you launch Visual Studio 2005 for the first time, you
will be asked to choose a default setting for the IDE. Among the list
of settings available are:

Web Development Settings

Visual Basic Development Settings

Visual C# Development Settings

Depending on which setting you choose, you will get a slightly
different menu setup.

Note: With Visual Studio 2005, it's now easier
than ever to start building an ASP.NET web application.
You've got to try it to believe it!

1.1.1. How do I do that?

To get a feel for how you create a new web application in Visual
Studio 2005, try walking through the following steps. First
we'll open the application, pick a location to host
it for development, and then add a second web form. Finally, we will
see how we can debug the application.

You can change the IDE settings (listed in Sidebar 1-2
via
Tools Import and Export
Settings.... Since this book is all about web development, we
naturally suggest you select Web Development Settings. Launch Visual
Studio 2005. If you selected the Web Development Settings option in
Visual Studio 2005, go to the File menu and select New Web Site...,
as shown at the top of Figure 1-1. If you have
chosen any other setting, go to the File menu and choose
New Web Site... (see the
bottom part of Figure 1-1).

Figure 1-1. Creating a new web site in Visual Studio 2005

When the New Web Site dialog box appears, select a project
template from the Templates pane. Since we're
creating a blank ASP.NET web site in this lab, select the ASP.NET Web
Site template.

In the New Web Site dialog, you need to choose a development language
and a place to locate the project. We'll be using
Visual Basic as our language of choice throughout this book, so from
the Language drop-down listbox, select Visual Basic.

Visual Studio 2005 provides four ways to develop a web site. For this
lab, you'll use the File System option. Choose File
System from the Location drop-down list. This
new ASP.NET 2.0 option frees you from
having to use IIS (Microsoft Internet Information Server) for
development. Instead, Visual Studio 2005 provides its own built-in
web server, which it launches when you run the web application. Use
C:\ASPNET20\ as the location of your
application and chap01-WebSite1
as its name. Type the complete
pathname, C:\ASPNET20\chap01-WebSite1, into the
drop-down combo box to the right of the Location box.

Note: No more worries about creating virtual directories on your
web server! Visual Studio 2005 comes with a file-based web server for
developing ASP.NET 2.0 applications. Now you can also develop ASP.NET
2.0 web applications on a Windows XP Home Edition PC, which
traditionally does not include IIS.

Figure 1-2 shows the completed New Web Site dialog.

Figure 1-2. Selecting a project language, template, and location

Tip: For all subsequent examples in this book, you will use
C:\ASPNET20\ as the directory in which to store
your projects.

If you do wish to use IIS for development purposes,
select HTTP from the Location drop-down list and enter a URL for the
application instead, such as http://localhost/chap01-WebSite1.

Order of Installation

If you wish to use
IIS to develop your ASP.NET web applications, you must install IIS
before installing Visual Studio 2005. By default, Windows XP does not
install IIS, and so you need to retrieve your Windows XP Installation
CD and then use Control
Panel Add or Remove
Programs Add/Remove
Windows Components
Components: Internet Information Services (IIS) to add IIS yourself.

In the event that you have installed Visual Studio 2005 before
installing IIS, you need to associate IIS with ASP.NET. You can do so
by using the aspnet_regiis utility (located in
C:\WINDOWS\Microsoft.NET\Framework\<version>)
with the -i option, like this:

aspnet_regiis -i

Once you have selected your template, language, and location, click
OK. Visual Studio creates your project, and the Solution Explorer
should display the files shown in Figure 1-3.

Figure 1-3. The Solution Explorer

By default, ASP.NET creates a folder named
App_Data and an initial application page, a Web
Form named Default.aspx with a code-behind page
named Default.aspx.vb (to see the contents of
this file, click the + symbol to the left of Default.aspx icon in the
Solution Explorer).

Switching Between Design View, Source View, and Code-Behind View

In Visual Studio 2005, a Web Form is displayed in Source View by
default. In Source View, you can modify the various attributes of the
form and the controls contained within it. To switch to Design View,
click on the Design button at the bottom of the screen. In Design
View, you can visually inspect the page and drag and drop controls
onto the form. To view the code-behind of the form, you can simply
double-click on the form and the code-behind will appear. In Code
View, you write your business logic for your application as well as
service the events raised by the various controls on the page. Figure 1-4 shows the three views.

Figure 1-4. Switching Between the Different Views

To add a new item (such as an additional Web
Form) to your project, you can right-click the project name and
select a template from the Add New Item... dialog box shown
in
Figure 1-5.

Figure 1-5. Adding a new item to your web project

Notice that you have the option to "Place code in
separate file." If this option is unchecked, your
code will reside in the same file as your Web Form. For all the
examples in this book, you will place the code in a separate file.
Hence, check the "Place code in separate
file" option. Click Add.

Tip: If you wish to debug your application (by using F5), you need to have
a Web.config file in your project. By default,
if there is no Web.config file when you try to
debug your application, Visual Studio will prompt you to add one.In Visual Studio 2005 (unlike Visual Studio .NET 2003),
Web.config is not automatically added to your
project. To add a Web.config file yourself,
simply go to the Add New Item... dialog box, and select Web
Configuration File from the "Visual Studio installed
templates" window.

1.1.2. What about...

...modifying the code generated by the Visual
Designer?

If you look at the code-behind of a Web Form, you
will
realize that the bulk of the user interface code generated by Visual
Studio is no longer visible, as it has been in ASP.NET 1.x. Instead,
you see a partial class:

Partial Class Default_aspx
End Class

You add your business logic to this partial class. Unlike ASP.NET
1.x, where the code-behind contains code generated by the Visual
Designer, ASP.NET 2.0 does not display this section. Instead, at
compile time, the Visual Designer automatically generates the partial
class needed to implement the user interface and merges it with your
code-behind.

The New Partial Keyword

One of the language enhancements in .NET 2.0available to both
VB2005 and C# 2.0 programmersis support for
partial classes. In a nutshell, partial
classes mean that your class definition can be split into multiple
physical files. Logically, partial classes do not make any difference
to the compiler. During compile time, it simply groups all the
various partial classes and treats them as a single entity.

One of the greatest benefits of partial classes is that they allow a
clean separation of business logic and the user interface (in
particular, the code that is generated by the Visual Studio
Designer). Using partial classes, the UI code can be hidden from the
developer, who usually has no need to access it anyway. Partial
classes also make debugging easier, as the code is partitioned into
separate files. This feature also helps members of large development
teams work on their pieces of a project in separate physical files.

...choosing another location for your web
application?

Visual Studio 2005 provides four possible locations for a web application. If you
are developing a simple web application (or are just trying out some
of the new features in ASP.NET), the quick and easy way to build the
application is to use the File System method. This method is also
useful for developers who do not have a web server (such as IIS)
installed on their machine, or for developers who are using Windows
XP Home Edition as their development workstation.

If you already have a web server installed on your machine and you
want to use it to host your web application, you can choose the Local
IIS method. Doing so allows your web application to be accessed from
other machines during development time.

If your web server is located remotely, such as in a hosting
environment, then you could use the FTP method. Use FTP Sites if
your hosting vendor supports FTP access. Alternatively, you can host
your application on another remote server through HTTP using the
Remote Web Site option. To use this option, the remote server must be
configured with the FrontPage Server Extensions.

Improved Debugging Support in ASP.NET 2.0

In ASP.NET 1.x, you need to explicitly
set a start page
in your project so that a specific page is loaded when you press F5
to debug the application. In ASP.NET 2.0, you can still set a
specific page as the start page if you want. However, you can also
set the start page as the currently selected page (currently selected
either because you're editing it or because you
selected the page in Solution Explorer). This feature saves you the
trouble of setting a start page when you just want to debug a page
you're working on at the moment.

This option is configurable via the Start Options item in the project
Property Pages dialog (right-click a project name in Solution
Explorer and then select Property Pages), as shown in see Figure 1-6.

Figure 1-6. The project Property Pages

1.1.3. Where can I learn more?

Visit the Visual Studio 2005 home page at http://lab.msdn.microsoft.com/vs2005/ for
information on the latest changes to Visual Studio 2005.

If you prefer to use the Visual Web Developer 2005 Express Edition,
head over to http://lab.msdn.microsoft.com/express/vwd/default.aspx
for information on how to download a trial copy.