Getting Started with .NET Development Using C#

May 30, 2013

␡

⎙ Print

Page 1 of 5 Next >

Bart De Smet shows you how to install the .NET Framework, write a simple C# application, go through the process of building it using various tools, and debug code.

Read C# 5.0 Unleashed and more than 24,000 other books and videos on Safari Books Online. Start a free trial today.

This chapter is from the book 

C# 5.0 Unleashed

Learn More Buy

Time to set yourself up for a successful journey through the world of .NET development using C#. An obvious first thing to tackle is to install the .NET Framework and the necessary tools so that we can start running and writing code. One tool we pay a fair amount of attention to is Visual Studio 2012, but we cover other useful tools, too.

To get our hands dirty, we write a simple C# application and highlight some of the important language elements, go through the process of building it using various tools, and look at how we can debug code.

Installing the .NET Framework

The first logical step to get started with writing code targeting the .NET Framework is to install it on your development machine. At this point, let’s skip the in-depth discussion on how to deploy the .NET Framework to the machines where your application code is to run ultimately, be it a client computer, a web server, or even the cloud.

The .NET Framework Version Landscape

Over the years, various versions of the .NET Framework have been released. In this book, we cover the latest (at the time of this writing) release of the .NET Framework, version 4.5, which goes hand in hand with the Visual Studio 2012 release.

Does that mean you can’t use the knowledge you gain from .NET 4.5 programming to target older releases of the framework? Certainly not! Although the .NET Framework has grown release after release, the core principles have remained the same, and a good part of the evolution is to be found at the level of additional application programming interfaces (APIs) that are made available through the class libraries. A similar observation of evolution obviously holds on the level of the managed languages: Features are added every time around that often require additional framework support (for example, Language Integrated Query [LINQ] in C# 3.0, dynamic in version 4). As you can imagine, keeping track of all those versions and their key differentiating features isn’t always easy. To make things more clear, take a look at Table 3.1.

Table 3.1. .NET Platform Version History

Version	Codename	Visual Studio	C#	VB	Flagship Features
1.0	Lightning	2002 (7.0)	1.0	7.0	Managed code
1.1	Everett	2003 (7.1)	1.0	7.0
2.0	Whidbey	2005 (8.0)	2.0	8.0	Generics
3.0	WinFX	2005 (8.0)	2.0	8.0	WPF, WCF, WF
3.5	Orcas	2008 (9.0)	3.0	9.0	LINQ
4.0	Dev10	2010 (10.0)	4.0	10.0	Dynamic
4.5	Dev11	2012 (11.0)	5.0	11.0	Asynchronous programming

Notice that new releases of the .NET Framework typically go hand in hand with updates to the Visual Studio tooling support. A notable exception to this rule was the .NET 3.0 release, where Visual Studio 2005 additions were made to support the newly added features (for example, by providing designer support for Windows Presentation Foundation [WPF]). Notice, however, how the managed languages evolve at a slightly slower pace. It’s perfectly imaginable that a future release of the .NET Framework will still be using C# 5.0 and VB.NET 11.0. History will tell.

NOTE: What About Operating System Integration?

Being a logical extension to the Win32 API for Windows programming, it very much makes sense to have the framework components readily available together with various versions of the Windows operating system. However, Windows and the .NET Framework have been evolving at a different pace, so the innovation on the level of the .NET Framework hasn’t always been immediately available with the operating system out there at that point in time.

One first little piece of integration with the operating system happened with Windows XP, where the image loaded was made aware of the existence of managed code, to be able to load managed executables with fewer workarounds than would be required otherwise. In the Windows Server 2003 era, the 1.1 release of the .NET Framework was brought to the operating system so that the ASP.NET web stack was available out of the box for use in web server installations.

The bigger integration story happened around Vista, driven by the WinFX vision of enhancing core system capabilities like windowing (with WPF) and communication (with WCF). For a long time during the development of Vista—known as Longhorn at the time—WinFX formed a core pillar of the next-generation operating system, and development proceeded hand in hand with the operating system. Only later was WinFX decoupled from Vista and ported back to other platforms, resulting in what became known as .NET Framework 3.0. This said, the .NET Framework 3.0 components still shipped with Windows Vista as an optional Windows component that can be turned on or off. The same holds for Windows Server 2008.

With the release of Windows 7, this tradition continued by making the .NET Framework 3.5 components available out of the box. More recently, with Windows 8, the .NET Framework 4.5 shipped out of the box with the product. But there’s more. Thanks to the tight integration with Windows Runtime, we can now truly speak of a better together story where the power of Windows is readily accessible for .NET developers.

What Table 3.1 doesn’t show is the versioning of the Common Language Runtime (CLR). There’s a very important point to be made about this: The CLR evolves at a much slower pace than the libraries and languages built on top of it. Slow most often has a pejorative feel to it, but for the CLR this is a good thing: The less churn made to the core of runtime, the more guarantees can be made about compatibility of existing code across different versions of the .NET Framework. Figure 3.1 illustrates this nicely based on the .NET Framework 3.x history.

Figure 3.1. .NET Framework 3.x is built on CLR 2.0.

From this figure, you can see how both .NET Framework 3.0 and .NET Framework 3.5 are built to run on top of the existing CLR 2.0 runtime bits. This means that for all the goodness that ships with those versions of the .NET Framework, no changes were required to the core execution engine, a good sign of having a solid runtime that’s ready to take on a big job.

NOTE: Red Bits Versus Green Bits

A concept you might sometimes hear from Microsoft people in the context of framework versioning is that of red bits and green bits. The categorization of framework assemblies in red bits and green bits was introduced in the .NET 3.x timeframe to distinguish between new assemblies (green bits) and modifications to existing ones (red bits). Although .NET 3.x mostly added new library functionality to the existing .NET 2.0 layer, some updates were required to assemblies that had already shipped. With the distinction between red bits and green bits, development teams kept track of those modifications also to minimize the changes required to red bits to reduce the risk of breaking existing applications.

What all this means in practice is that .NET 3.0 is a superset of .NET 2.0, but with some updates to the .NET 2.0 binaries, in the form of a service pack. Those service packs are also made available by themselves because they contain very valuable fixes and optimizations, and they are designed to be fully backward compatible so as not to break existing code. Windows Update automatically deploys these service packs to machines that already have the framework installed.

NOTE: Lost in Translation

Even more remarkable than the capability to add gigantic libraries like WPF and Windows Communication Foundation (WCF) on an already existing runtime without requiring modifications to it is the fact that very powerful language extensions have been made in .NET 3.5 with the introduction of LINQ. However, none of those new language additions required changes to the runtime or intermediate language (IL). Therefore, C# 3.0 and VB 9.0 programs can run on the .NET 2.0 CLR. Even more, it’s theoretically possible to cross-compile C# 3.0 programs into C# 2.0 code with an equivalent meaning. A paper proving this claim was written by a group of language designers at Microsoft and is titled “Lost in Translation.”

One caveat, though: Don’t take this to mean that C# 3.0 programs can be ported blindly to .NET 2.0 because implementations of various LINQ providers ship in various .NET 3.5 assemblies.

Another advantage that comes from keeping the runtime the same across a set of framework releases is the capability to reuse existing tooling infrastructure (for example, for debugging). With the release of Visual Studio 2008, this capability became visible to .NET developers under the form of multitargeting support. What this feature enables is to use Visual Studio 2008 to target .NET Framework 2.0, 3.0, and 3.5 using the same comfortable tooling environment. And with .NET 4.0 and .NET 4.5—as you’ll see later in this chapter when we explore Visual Studio 2012—multitargeting has been extended to support all releases from .NET 2.0 to 4.5.

What about .NET Framework 1.x? Development targeting those platforms will always be tied to the use of the releases of Visual Studio that shipped with it (that is, Visual Studio .NET versions 2002 and 2003). Too many fundamental changes to runtime infrastructure were made between versions 1.x and 2.0 of the CLR, making multitargeting support for .NET 1.x unfeasible. Luckily nowadays, the use of .NET 1.x has largely been phased out. If you still have .NET 1.x applications around, now is the time to port them to a more recent version of the platform (preferably .NET 4.0, of course).

But why should someone care to target an older release of the .NET Framework? Most commonly, the answer is to be found in deployment constraints within companies, web hosting providers, and so on. Having tooling support to facilitate this multitargeting is pure goodness and also means you can benefit from core enhancements to the Visual Studio tools while targeting older releases of the .NET Framework.

.NET Framework 4.5

The particular version of the .NET Framework we target in this book is .NET 4.5, using Visual Studio 2012 and C# 5.0. Other than the .NET 3.x releases, .NET 4.x has a new version of the CLR underneath it, and obviously—in the grand tradition—it comes with a bunch of new class libraries that will make life easier for developers.

Two key features about .NET 4.x are important to point out here:

Side-by-side support: This means that .NET 4.x can be installed next to existing versions of the .NET Framework. What’s so special about this compared to .NET 3.x? The key difference is updates to existing class library assemblies are no longer carried out in-place, but new versions are put next to the existing ones.
Backward compatibility: This provides tremendous value to developers, allowing reuse of existing code and components. In practice, it means that existing code that was compiled against .NET 2.0 or 3.x in the past can now be targeted at .NET 4.x without requiring source-level code changes.

Figure 3.2 illustrates a machine with all the versions of the .NET Framework installed next to one another.

Figure 3.2. Side-by-side installation of .NET Framework versions.

With .NET 2.0, it made sense to give more meaning to the build number, and the pattern ymmdd was chosen: one digit for the year (2005), two digits for the month (July), and two for the day (27).

This approach worked very nicely until the theoretical 35th day of the 55th month of the year 2006: The metadata encoding for build numbers cannot exceed 65535, so we’re out of luck using this pattern in its full glory. The result was a compromise. The month and year encodings are kept the same, but the year is now considered relative to the start of the release. For the .NET 4.0 release, the start of the release was in 2007, so from Figure 3.2, one can infer that .NET 4.0 was built on March 19, 2012. Because the .NET 4.5 release is an in-place update, the folder name has stayed the same, even though the revision number of the files in the folder has gone up.

Besides having various versions of the .NET Framework, .NET 4.0 pioneered the availability of different “flavors.” Around the .NET 3.5 timeframe it became apparent that the size of the .NET Framework had grown too large to enable fast friction-free installs, which are especially important for client application deployments. Significant factors for such deployments are download times and installation times.

To streamline typical deployments of the framework, a split of the .NET Framework class libraries was made, factoring out so-called Client Profile assemblies. The Client Profile bubble contained the Base Class Library (BCL) and libraries required to write client applications using WPF and WCF. The remaining part (referred to as Extended Profile) was layered on top of the Client Profile subset and contained features like ASP.NET that client applications typically don’t need. As a result, the deployment and installation footprint of the Client Profile is kept small, while it’s still possible to upgrade such an installation to the full framework. Figure 3.3 shows the layered cake architecture of those profiles in the .NET 4.0 timeframe.

Figure 3.3. Client Profile subset of the .NET Framework.

Together with this split, Visual Studio 2010 extended its notion of multitargeting to the various “profiles” of the .NET Framework. By doing so, developers didn’t have to memorize which libraries are available in each profile. When the Client Profile subset is selected, Visual Studio prevents assemblies from the Full framework from being referenced.

During the .NET 4.5 timeframe, a big investment was made to reduce download and installation sizes and to decrease the installation time. As a result, the split of a Client Profile and Extended Profile was no longer necessary, resulting in the discontinuation of the Client Profile package.

.NET 4.5 introduces a new notion of profiles though, through the new Portable Library support. When writing portable class libraries, you can select the target platforms the library can run on. For example, you could build a portable library targeting .NET Framework 4.5, .NET for Windows Store applications, and Windows Phone 8. The resulting project will have access only to the .NET Framework functionality available in the intersection for those platforms, hence ensuring the resulting assembly works on all of the selected platforms. In the past, developers had to maintain separate builds of their libraries for each target platform, causing major grief. Portable Library aims to take away this pain.

To make the intersection of APIs across different target platforms as stable as possible, the bottommost layer of the framework was split off in a “.NET Core” set of assemblies. This foundation is what future releases of the framework are based on, and is used by .NET 4.5 on the desktop, .NET for Windows Store applications, and Windows Phone 8. When you are targeting older platforms, such as Silverlight or .NET 4.0, the set of APIs available in the intersection will differ because of prior differences between different flavors of the .NET Framework. With the .NET Core and Portable Library refactoring in place, the fragmentation of the framework libraries should be reduced substantially.

Running the Installer

Playtime! To write code on the .NET Framework 4.5, let’s start by installing the Full .NET Framework package. That’s really all you need to get started with managed code development.

Where to get it? Browse to http://msdn.com/netframework and click the link to the .NET Framework 4.5 download. The installer itself should be straightforward to run: Accept the license agreement, get a cup of coffee, and you’re ready to go. On Windows 8, you can use the Turn Windows Features On or Off Control Panel applet to enable or disable the .NET Framework 4.5 feature. Figure 3.4 shows the default feature selection on a clean Windows 8 installation.

Figure 3.4. .NET Framework 4.5 enabled by default on Windows 8.

What Got Installed?

When the installation is complete, it’s good to take a quick look at what was installed to familiarize yourself with where to find stuff.

The Runtime Shim

The runtime shim is really something you shouldn’t care much about, but it’s a convenient way to find out the latest version of the installed CLR on the machine. The purpose of the shim is to load the correct version of the CLR to execute a given application, a particularly important task if multiple versions of the runtime are installed.

You can find the shim under %windir%\system32, with the name mscoree.dll. By looking at the file properties (shown in Figure 3.5), you’ll find out about the latest common language runtime version on the machine.

Figure 3.5. The version of the CLR runtime shim.

Although the file description states “Microsoft .NET Runtime Execution Engine,” this is not the CLR itself, so where does the runtime itself live?

The .NET 4.0 CLR

Having a runtime shim is one thing; having the runtime itself is invaluable. All runtime installations live side by side in the %windir%\Microsoft.NET\Framework folder. On 64-bit systems, there’s a parallel Framework64 folder structure. Having two “bitnesses” of the CLR and accompanying libraries is required to allow applications to run either as 32-bit (Windows On Windows, or WOW) or 64-bit.

Starting with .NET 4.0, the CLR itself is called clr.dll (previously, mscorwks.dll), as shown in Figure 3.6. The same CLR is used for .NET 4.5, so we’ll refer to it using the 4.0 version number.

Figure 3.6. The CLR itself.

The Global Assembly Cache

The Global Assembly Cache (GAC) is where class library assemblies are loaded for use in .NET applications. You can view the GAC under %windir%\assembly, but a command-line directory listing reveals the structure of the GAC in more detail. We discuss the role of the GAC and the impact on your own applications exhaustively in Chapter 25, “Assemblies and Application Domains.”

Figure 3.7 shows the structure of the .NET 4.0 GAC containing the 4.0 version of the System.dll assembly, one of the most commonly used assemblies in the world of managed code development.

Figure 3.7. Inside the GAC.

NOTE: GAC Splitting

Notice the v4.0 prefix in the name of the folder containing the .NET 4.0 version of System.dll? This is an artifact of the “GAC splitting” carried out in .NET 4.0. This simple naming trick hides assemblies targeting different versions of the runtime so that a specific version of the CLR doesn’t try to load an assembly that’s incompatible with it. In the preceding example, CLR 2.0 will recognize only the first folder as a valid entry in the GAC, whereas CLR 4.0 recognizes only the second one. This truly shows the side-by-side nature of the different runtimes.

Tools

Besides the runtime and class library, a set of tools get installed to the framework-specific %windir%\Microsoft.NET\Framework folder. Although you’ll only use a fraction of those on a regular basis—also because most of those are indirectly used through the Visual Studio 2012 graphical user interface (GUI)—it’s always good to know which tools you have within reach. My favorite tool is, without doubt, the C# compiler, csc.exe. Figure 3.8 shows some of the tools that ship with the .NET Framework installation.

Figure 3.8. One of the .NET Framework tools: the C# compiler.

You can find other tools here, too, including other compilers, the IL assembler, MSBuild, the NGEN native image generator tool, and so on.

We explore quite a few of the tools that come with the .NET Framework throughout this book, so make sure to add this folder to your favorites.

Page 1 of 5 Next >

🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Privacy Notice

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
Such marketing is consistent with applicable law and Pearson's legal obligations.
Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

As required by law.
With the consent of the individual (or their parent, if the individual is a minor)
In response to a subpoena, court order or legal process, to the extent permitted or required by law
To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
To investigate or address actual or suspected fraud or other illegal activities
To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020

Email Address