WIX: don't show build number from [ProductVersion] - wix

Question

My Wix installer has the product version set like this:
<Product Version="4.6.0.0" ..>
And I show it in the UI like this:
<String Id="WelcomeDlgTitle">{\WixUI_Font_Bigger}Welcome to the [ProductName] v[ProductVersion] Setup Wizard</String>
This works well but I would like to omit the build number (ie. v4.6.0 instead of v4.6.0.0). Is there a way to do this?

Answer 1

You can omit the 4th field of the Product/#Version attribute as Windows Installer ignores it anyway.
<Product Version="4.6.0" ..>
If you really want to keep the 4th field of the version number, you'd have to write a custom action to parse the string and strip the 4th field.

Answer 2

Thank you #zett42, your comment pointed me out in the right direction - I created a Wix Preprocessor Extension, following the documentation here: http://wixtoolset.org/documentation/manual/v3/wixdev/extensions/extension_development_preprocessor.html
Here are the classes I created:
public class MaterialiserExtension : WixExtension
{
private MaterialiserPreprocessorExtension preprocessorExtension;
public override PreprocessorExtension PreprocessorExtension
{
get
{
if (this.preprocessorExtension == null)
{
this.preprocessorExtension = new MaterialiserPreprocessorExtension();
}
return this.preprocessorExtension;
}
}
}
public class MaterialiserPreprocessorExtension : PreprocessorExtension
{
private static string[] prefixes = { "versionUtil" };
public override string[] Prefixes { get { return prefixes; } }
public override string EvaluateFunction(string prefix, string function, string[] args)
{
string result = null;
switch (prefix)
{
case "versionUtil":
switch (function)
{
case "ToString":
if (0 < args.Length)
{
result = Version.Parse(args[0]).ToString(args.Length >1 && args[1] != null ? int.Parse(args[1]) : 4);
}
else
{
result = String.Empty;
}
break;
}
break;
}
return result;
}
}
One thing that was not immediately obvious - in my Visual Studio Wix project, I had to add
-ext "$(SolutionDir)Materialiser.Wix\bin\Release\Materialiser.Wix.dll" to Properties (Alt+Enter) > Tool Settings > Compiler (candle) and the same in Linker (light).
To use, it is very simple:
in my .wxs file I define a property like this:
<?define ProductVersion="4.6.0.5" ?>
Then I use it in Product like this:
<Product Version="$(var.ProductVersion)" .. >
And then I create anew property like this:
<Property Id="VersionWithNoBuildNumber" Value="$(versionUtil.ToString([ProductVersion], 3))" />
and in my .wxl file I use it normally:
<String Id="WelcomeDlgTitle">{\WixUI_Font_Bigger}Welcome to the [ProductName] v[VersionWithNoBuildNumber] Setup Wizard</String>
I hope this helps someone else too :p