.Net Framework Essentials

CLR Executables

Microsoft .NET executables are different from typical Windows executables in that they carry not only code and data, but also metadata (see “Metadata” and “Intermediate Language” later in this chapter). In this section, we start off with the code for several .NET applications, and then discuss the .NET PE format.

Hello, World: Managed C++

Let’s start off by examining a simple Hello, World application written in Managed C++, a Microsoft .NET extension to the C++ language. Managed C++ includes a number of new .NET-specific keywords that permit C++ programs to take advantage of .NET’s new features, including garbage collection. Here’s the Managed C++ version of our program:

#using <mscorlib.dll>
using namespace System;

void main(  )
{
  Console::WriteLine(L"C++ Hello, World!");
}

As you can see, this is a simple C++ program with an additional directive, #using (shown in bold). If you have worked with the Microsoft Visual C++ compiler support features for COM, you may be familiar with the #import directive. While #import reverse-engineers type information to generate wrapper classes for COM interfaces, #using makes accessible all types from the specified DLL, similar to a #include directive in C or C++. However, unlike #include, which imports C or C++ types, #using imports types for any .NET assembly, written in any .NET language.

The one and only statement within the main( ) method is self-explanatory—it means that we are invoking a static or class-level method, WriteLine( ...