The file version number is a native code concept – meaning not originating from the .NET Framework. This version number is a resource found within the resource section of the windows PE (portable executable) format of a managed or native code dll. This resource is named “FILEVERSION”. This version number is used for information purposes only, not for any runtime purposes such as binding. In addition, this version number does not have to conform to a particular format, but is only a string, although it does typically takes the form of a simple four-part number (i.e. 1.2.3.4).
Reading the File Version
The easiest way to view this number is to view the properties of a file in Windows Explorer. The version number listed is the file version number. The product version is also listed, although I don’t know how the two numbers differ exactly. Naturally, you can access the file version from code. The following code does just that, largely using the System.Diagnostics.FileVersionInfo class, which I’ve never used before. In fact, I had to ask someone else on the loader team for that information.
using System;
using System.Reflection;
using System.Diagnostics;
namespace FileVersion
{
class Program
{
static void Main(string[] args)
{
Assembly asm = Assembly.Load("mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089");
System.Diagnostics.FileVersionInfo fvi = FileVersionInfo.GetVersionInfo(asm.Location);
Console.WriteLine(fvi.FileVersion);
}
}
}
Setting the File Version
The CLR provides an assembly-level custom attribute to set this version number for an assembly from managed code. This attribute is called System.Reflection.AssemblyFileVersion. You can see how to set it below.
using System;
using System.Reflection;
[assembly:System.Reflection.AssemblyFileVersion("2.3.4.5")]
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("I just set the file version!");
}
}
}
You can actually set this attribute in Visual Studio 2005 via the properties menu. In that case, you cannot set it in code, as I’ve done above, since you’ll then have two instances of the attribute. You only need to set the attribute directly, as I’ve done above, if you are using the compiler directly, from the commandline.