You've heard the hype about .NET. You've read a couple of vague articles about dynamic discovery and invocation, service-oriented architecture, and how SOAP and a handful of other XML standards are forever changing the software industry. These ideas have intrigued you and you're interested in learning more - or at the very least, you recognize the importance of being able to add these acronyms to your resumé. In either case, you want to explore the world of .NET, but are unable or unwilling to fork over a thousand bucks for Microsoft's Visual Studio .NET product. This article is for you.
The Eclipse Project
Visual Studio .NET is not the only option for exploring .NET in a commercial-quality integrated development environment (IDE); it's just the most expensive one. On November 5, 2001, IBM released the Eclipse project (with an estimated value of $40 million worth of software) to the open-source community. The project is now maintained by the Eclipse organization (www.eclipse.org). This open-source software provides a core, extensible infrastructure for building software development environments. It also provides a basic user interface and an open API that supports the extension of the product through its plug-in mechanism. Eclipse provides a framework for producing customized software development environments that can either be used internally by an organization or repackaged and sold commercially. In fact, the Eclipse framework is the foundation for IBM's new suite of WebSphere Workbench tools.
What does all of this have to do with .NET development? When you combine Eclipse (an open-source IDE) with Microsoft's .NET SDK (a free download) and the C# plug-in for Eclipse provided by Improve Technologies (also open-source), you have a comprehensive .NET application development platform that costs no money, and uses less than 400MB of hard disk space!
This article will walk you through the process of setting up a free C# .NET development environment on a Windows 2000 machine (the recommended platform) and deploying a simple C# application. This combination of tools will also work on Windows 95/98, XP, and NT 4.0 (the .NET SDK currently limits you to a Windows OS).
Environment Setup
Before starting, check Table 1 to be sure your system has the appropriate resources for this configuration.
Although the minimum and recommended values listed in Table 1 are accurate, you'll be much happier if you have more horsepower available. I'm running this configuration on a P4 1.6GHZ Dell Inspiron with 512MB and plenty of free hard drive space.
Assuming your system has the appropriate resources, you will need to download two components:
1. The Eclipse 2.0 IDE (www.eclipse.org/downloads/index.php):Windows OS.
2. The .NET Framework SDK ( http://msdn.microsoft.com/netframework/ downloads/howtoget.asp): Be sure to get the SDK, not just the runtime framework. You can download the SDK as a single 130MB file (setup.exe), or ten 13MB files and a batch file (setup.bat).
Once you've downloaded Eclipse and the .NET SDK, you can install the software. To install Eclipse, simply extract the Zip file in the parent directory where you would like to store Eclipse (it will create a new directory called "Eclipse"). To install the .NET SDK, run the setup file and follow the prompts to install and register the appropriate components. (You may be prompted to first install Data Access Components 2.7 and Microsoft Internet Information Services, but these components are only needed for ASP.NET development.)
Eclipse Primer
The Eclipse IDE (shown in Figure 1) is divided into two basic levels: the Workspace and the Workbench:
- Workspace: Files, packages, projects, source control connections
- Workbench: Editors, views, and perspectives
This division isn't readily apparent, and isn't labeled within the IDE, but it is an important distinction to understand when working with Eclipse or an Eclipse-based tool.
The Workspace is very team-centric, focusing on projects and file resources as well as providing integrated source-control capabilities for these resources, such as CVS or Rational's ClearCase. The Workspace is also somewhat transient in that it reflects the current state of the local projects, source, and compiled files that are in active memory. The Workspace also consists of currently active Workbench elements (explained below). When you close Eclipse, it saves the current state of the local Workspace, allowing developers to restart Eclipse and pick up right where they left off.
The Workbench consists of the visual artifacts that sit atop the Workspace resources and provide distinct views and role-based perspectives of the underlying projects and resources. The user interface paradigm is based on editors, views, and perspectives:
Editor: An editor is a component that allows a developer to interact with and modify the contents of a file (source code, XML file, properties file, etc.). This is the standard text area where application source code is modified within an IDE. Figure 2 is a screen shot of the C# editor, which we will install later.
View: Views provide metadata about the currently selected resource. This data is pertinent to, but not directly related to, the actual contents of the resource (the contents would be accessed via an editor). The outline of a resource's contents; the status of compilation, resource, and element properties; and the organization of a resource within a package or project are all examples of views within Eclipse.
Perspective: A perspective represents a configuration of related editors and views, as well as customized menu options and compile settings. Eclipse comes with three standard perspectives (CVS, Install/Update, and Resource), and the ability to plug in additional ones as needed. Switching between perspectives brings up different editors, views, and menu options. Perspectives are either tailored to a particular task, an application development role, or both.
Installing the C# Plugin
To install the Improve Technologies C# Plug-in, we will use the built-in update feature, the Eclipse update manager. To do so, you will need Internet connectivity, and to follow these steps:
1) Open Eclipse by running eclipse.exe in the base of the eclipse directory.
2) Open the Update Manager perspective (Help -> Software Updates -> Update Manager).
3) In the "Feature Updates" view (bottom left), right-click in the view window and select: New -> Site Bookmark...
4) Fill the Name field with "Improve's Eclipse Plugin Site", and the URL with "www.improve technologies.com/alpha/updates/site.xml". This XML file describes the plug-ins available for download from Improve Technologies, and will allow you access to those plug-ins now, and in the future.
5) A new bookmark, "Improve's Eclipse Plug-in Site," has been added. Expand it untill you find the newest Improve C# plugin feature ("C Sharp Feature x.x.x"). If you select the feature, its description will be displayed in the "Preview" view. You can read the license agreement by clicking the link.
6) In order to install the feature, click the "Install" button in the "Preview" view: click "Next" for each page; and then "Finish". On the last page ("Feature Verification"), click on the "Install" button. Eclipse will automatically install the feature, and you will be asked whether you want Eclipse to reboot or not. Say yes.
7) Once Eclipse has rebooted, you can check that the feature has been installed: expand the item "Current Configuration" (in the "Install Configuration" view), and you will find the feature in the list of the installed features. If you expand "Configuration History", you will see all the previous configurations. You can save a specific configuration so you can restore it later: right-click on a configuration and click "save".
8) The last step is to configure the new Eclipse C# perspective to use the .NET C# compiler that was installed with the .NET SDK earlier. To configure the C# compiler, navigate to the Eclipse Workbench preferences (Window -> Preferences) and select the C# Preferences item. This preferences window should now look similar to Figure 3. To specify the C# compiler (csc.exe), click the "Browse" button and navigate to the Microsoft .NET/Framework directory. On Windows 2000, that directory is C:\WINNT\Microsoft.NET\Framework\v1.0.3705\csc.exe. (The name of the directory under the Framework directory may vary depending upon what version of the .NET SDK you have installed.)
Sample C# .NET Application
Now we'll walk through the creation of an Eclipse project containing a single C# program. We'll verify our success by executing the completed program, and finally, we'll touch on a few of the available application development tools (keyword content assistance, task view usage, and file-level compiler arguments) that come with Eclipse and the C# plug-in.
To begin, we'll open a new project. As with any good tool, there are several ways to do this. You can click the "New Wizard" button directly (leftmost button below the menu bar), select the New Wizard drop-down (the drop-down arrow on right-hand side of New Wizard button), or use the menu bar (FileNewProject). The New Project window should now be open. Select "Simple" on the left and "Project" on the right. Click the "Next" button, assign a unique name for the project, and then click the "Finish" button.
Next, use the File menu or the New Wizard to create a new C# file. If you use the New Wizard drop-down or File menu, select the "Other" option (this is the equivalent of clicking the New Wizard button directly). Whichever path you take, the New window will provide two categories: C# and Simple. Select the "C#" category on the left and "C# File" on the right. Click the "Next" button and provide a name for the C# file. We'll use "CSharpTest.cs" for this example ("new_file. cs" is provided by default). Also, be sure that the correct project name is provided in the Container field. Finally, click the "Finish" button.
Now it's time to actually write the program. Enter the code displayed in Listing 1. When run, this code constructs a simple object with a single instance field of type DateTime containing a value corresponding to the current system time and date. The program output consists of a brief text greeting followed by the current time and date.
To save the file, click the disk icon at the top, use the menu system (FileSave), or hit Ctrl-S. When you save, Eclipse will also attempt to automatically compile the program (unless you turn this option off in the C# Preferences window). If there are any compilation problems, they will be displayed in the task view below the C# editor. Once you have resolved those issues, you are ready to execute the application. To do this, simply double-click on the CSharpTest.exe file that appears under the project you created. The result should be two lines of text. The first line displays a simple greeting and the second displays the time and date. To end the program, simply hit the return key.
Finally, there are a couple of features in Eclipse that you may find useful:
Compilation settings: Eclipse stores file-level compiler settings, including compiler arguments, output file type, and the specification of required .NET modules.
Content assistance: Hitting Ctrl-Space activates the C# plugin's content assistance dictionary. This dictionary is currently limited to keywords only (version 2.0.1).
Task view: In addition to displaying compiler problems, the task view can be manually manipulated to serve as a way of tracking progress, and recording project notes. You can create tasks for yourself, assign priorities to your tasks, check them off when complete, and filter them to display only certain kinds of tasks. Think of it as a virtual sticky pad that is associated with your Eclipse Workspace.
Conclusion
Web services are hot! (That's why you bought this magazine.) The .NET platform offers some intriguing possibilities for the development of XML Web services, and it's a good idea to explore it now and become familiar with the basic constructs. Unfortunately, the price tag on Visual Studio .NET is high, and setting up Visual Studio is a pain in the neck. The Eclipse Workbench, together with Microsoft's .NET SDK and Improve Technologies' C# Plugin, provides a powerful combination of tools that allows you to experiment with C# .NET application development, using a full-powered IDE - without paying a penny. Enjoy!
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