Welcome to the Daily Parker's 2018 Blogging A-to-Z challenge!
We're starting today with a fundamental concept in Microsoft .NET software development: the Assembly.
Microsoft defines the assembly as "a .dll or .exe file that can contain a collection of APIs that can be called by apps or other assemblies." In other words, an assembly is the basic unit of delivering .NET software to the rest of the world. An assembly "fully describe[s] and contain[s] .NET programs."
When you compile .NET source code, the compiler creates one or more of these files, each of with contains an Intermediate Language (IL) representation of your original code. You can then distribute the .dll or .exe files to any computer that has the correct version of the .NET Common Language Runtime (CLR) installed on it.
I've created a Visual Studio solution for this challenge. Today we're looking just at one small piece of it, which looks like this:
// ReSharper disable CheckNamespace
internal static class Program
// ReSharper disable once UnusedParameter.Local
private static void Main(string args)
If you're new to .NET, don't worry about all the pieces. This two-line program compiles into an assembly called HelloWorld.exe, which internally looks like this:
.method private hidebysig static void Main(string args) cil managed
// Code size 19 (0x13)
IL_0001: ldstr "Hello, World!"
IL_0006: call void [mscorlib]System.Console::WriteLine(string)
IL_000c: call valuetype [mscorlib]System.ConsoleKeyInfo [mscorlib]System.Console::ReadKey()
} // end of method Program::Main
Again—we're not going to get into a lot here. Suffice to say, that IL above is what actually lives in the assembly, and what the CLR will execute when you run the program. The assembly also contains a manifest, describing what it contains, and some metadata about its version, author, and whatever else the programming team has added to the assembly info file.
As with all of the topics for this year's A-to-Z challenge, I'm only scratching the surface. There is a ton more to read online and in some solid books on the market. The best information about assemblies I've found is in Jeffrey Richter's CLR via C#.
Note: the Visual Studio Solution for this challenge requires Visual Studio 2017 and the .NET Framework v4.7. ReSharper is also recommended.