Automatically update version number

With the "Built in" stuff, you can't, as using 1.0.* or 1.0.0.* will replace the revision and build numbers with a coded date/timestamp, which is usually also a good way.

For more info, see the Assembly Linker Documentation in the /v tag.

As for automatically incrementing numbers, use the AssemblyInfo Task:

AssemblyInfo Task

This can be configured to automatically increment the build number.

There are 2 Gotchas:

1. Each of the 4 numbers in the Version string is limited to 65535. This is a Windows Limitation and unlikely to get fixed.
   • Why are build numbers limited to 65535?
2. Using with with Subversion requires a small change:
   • Using MSBuild to generate assembly version info at build time (including SubVersion fix)

Retrieving the Version number is then quite easy:

Version v = Assembly.GetExecutingAssembly().GetName().Version;
string About = string.Format(CultureInfo.InvariantCulture, @"YourApp Version {0}.{1}.{2} (r{3})", v.Major, v.Minor, v.Build, v.Revision);

---

And, to clarify: In .net or at least in C#, the build is actually the THIRD number, not the fourth one as some people (for example Delphi Developers who are used to Major.Minor.Release.Build) might expect.

In .net, it's Major.Minor.Build.Revision.

What source control system are you using?

Almost all of them have some form of $ Id $ tag that gets expanded when the file is checked in.

I usually use some form of hackery to display this as the version number.

The other alternative is use to use the date as the build number: 080803-1448

VS.NET defaults the Assembly version to 1.0.* and uses the following logic when auto-incrementing: it sets the build part to the number of days since January 1st, 2000, and sets the revision part to the number of seconds since midnight, local time, divided by two. See this MSDN article.

Assembly version is located in an assemblyinfo.vb or assemblyinfo.cs file. From the file:

' Version information for an assembly consists of the following four values:
'
'      Major Version
'      Minor Version 
'      Build Number
'      Revision
'
' You can specify all the values or you can default the Build and Revision Numbers 
' by using the '*' as shown below:
' <Assembly: AssemblyVersion("1.0.*")> 

<Assembly: AssemblyVersion("1.0.0.0")> 
<Assembly: AssemblyFileVersion("1.0.0.0")> 

I have found that it works well to simply display the date of the last build using the following wherever a product version is needed:

System.IO.File.GetLastWriteTime(System.Reflection.Assembly.GetExecutingAssembly().Location).ToString("yyyy.MM.dd.HH.mm.ss")

Rather than attempting to get the version from something like the following:

System.Reflection.Assembly assembly = System.Reflection.Assembly.GetExecutingAssembly();
object[] attributes = assembly.GetCustomAttributes(typeof(System.Reflection.AssemblyFileVersionAttribute), false);
object attribute = null;

if (attributes.Length > 0)
{
    attribute = attributes[0] as System.Reflection.AssemblyFileVersionAttribute;
}