C# 4 and .NET 4

24 ❘ ChaPTer 2 cOre c#
Later chapters present a number of code samples. The most common technique for
writing C# programs is to use Visual Studio 2010 to generate a basic project and add
your own code to it. However, because the aim of Part I is to teach the C# language,
we are going to keep things simple and avoid relying on Visual Studio 2010 until
Chapter 16, “ Visual Studio 2010. ” Instead, we will present the code as simple fi les that
you can type in using any text editor and compile from the command line.
The Code
Type the following into a text editor (such as Notepad), and save it with a .cs extension (for example,
First.cs ). The Main() method is shown here (for more information, see “ The Main Method ” section later
in this chapter):
using System;
namespace Wrox
{
public class MyFirstClass
{
static void Main()
{
Console.WriteLine("Hello from Wrox.");
Console.ReadLine();
return;
}
}
}
code snippet First.cs
Compiling and running the Program
You can compile this program by simply running the C# command - line compiler ( csc.exe ) against the
source fi le, like this:
csc First.cs
If you want to compile code from the command line using the csc command, you should be aware that the
.NET command - line tools, including csc , are available only if certain environment variables have been set
up. Depending on how you installed .NET (and Visual Studio 2010), this may or may not be the case on
your machine.
If you do not have the environment variables set up, you have the following two
options: The fi rst is to run the batch fi le %Microsoft Visual Studio 2010%\
Common7\Tools\vsvars32.bat from the command prompt before running csc , where
%Microsoft Visual Studio 2010% is the folder to which Visual Studio 2010 has
been installed. The second, and easier, way is to use the Visual Studio 2010 command
prompt instead of the usual command prompt window. You will fi nd the Visual Studio
2010 command prompt in the Start menu, under Programs, Microsoft Visual Studio
2010, Visual Studio Tools. It is simply a command prompt window that automatically
runs vsvars32.bat when it opens.
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