WTV: Automatic date-based version numbering for .Net with WhenTheVersion

3 minute read

There’s a trend towards using the software build date as part of the software version number, you know the sort of thing I mean: 2011.11.4.xyz, like in the footer over at StackOverflow.com, or MyLetts.com

WTV Date-version example: MyLetts.com

Wouldn’t it be great if we could get Visual Studio to do this for us automatically on build?  I thought so too, so I’ve written a little app to do it 🙂

Getting set up with “When The Version”

  1. Grab a copy of “When The Version” WTV.exe from the GitHub download page (or you can build it from the source if you prefer)
  2. Drop it somewhere on your PC
  3. Now, in your Visual Studio project, expand the Properties and duplicate the AssemblyInfo.cs / .vb file - I rename the duplicate to AssemblyInfo.Template.cs:

AssemblyInfo.Template.cs - Solution Explorer

  1. Edit the AssemblyInfo.Template.cs file, putting in the placeholders for the date parts like so:
// 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 Revision and Build Numbers
// by using the '*' as shown below:
// [assembly: AssemblyVersion("1.0.*")]
[assembly: AssemblyVersion("{YYYY}.{MM}.{DD}.0")]
[assembly: AssemblyFileVersion("{YYYY}.{MM}.{DD}.0")]

The following values are currently supported:

  • {YYYY} - the year
  • {MM} - the month
  • {DD} - the day
  • {SVN} - SubVersion revision number (more on this a bit later)
  1. Now, open up the Project Properties > Build Events, and add the following Pre-build event command line (on a single line):
"C:\Path\To\wtv.exe" "$(ProjectDir)Properties\AssemblyInfo.Template.cs" "$(ProjectDir)Properties\AssemblyInfo.cs"
  1. Finally, set the Build Action for the new AssemblyInfo.Template.cs file to 'None' and Build!

If you get stuck, pop open a Command Prompt and run wtv without any parameters for usage instructions, or paste your full command line to see any helpful error messages:

WTV: Command prompt usage

SubVersion support

If you’re using SubVersion for your source control, WTV can also put the projects SVN revision number into the application version.

There’s only one caveat - .Net Application version number values are limited to a maximum of 65,535 (i.e. they’re UInt16 / ushort). Therefore, if your SVN revision is higher WTV will only use the last 4 digits: e.g.: 65535 -> 5535.

To use the SVN revision number, simply add the {SVN} placeholder to your AssemblyInfo.Template.cs / .vb file like so:

[assembly: AssemblyVersion("{YYYY}.{MM}.{DD}.{SVN}")]
[assembly: AssemblyFileVersion("{YYYY}.{MM}.{DD}.{SVN}")]

.. and then add a couple of extra parameters to the Pre-build event command line so WTV knows where SubWCRev.exe is, something like this (again, on a single line):

"C:\Program Files\TortoiseSVN\bin\SubWCRev.exe"

And because the AssemblyInfo.cs is generated, you can remove it from source control (but don’t remove it from your project!).


Comments and suggestions are welcome here or on the projects issue tracker over at GitHub. I hope you find it useful 🙂