How to automatically substitute string at compile time (C# DLL)

Question

I am compiling a DLL using Visual Studio 2013 and for technical reasons cannot use System.Version since it is not supported in one of my target runtime environments.

Is there a way to automatically place the assembly "FileVersion" into a constant at compile-time?

public const string MyFileVersion = "{{ PLEASE REPLACE ME }}";

I am not using a build server or anything fancy like that, just Visual Studio 2013.

Answer 1

Seems like t4 templates could help you. It's template generation engine. There are enough info about it which will be helpful.

I made a simple template which does what you want. It's just an example and probably you need to make some adjustments in the code:

<#@ template debug="false" hostspecific="true" language="C#" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="Microsoft.CSharp.dll" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.IO" #>
<#@ import namespace="System.Text.RegularExpressions" #>
<#@ import namespace="System.Reflection" #>
<#@ output extension=".cs" #>

<#
        var assemblyVersionRegex = new Regex(@"AssemblyVersion\(\""(?<version>(.*?))\""\)");
        var pathBase = new FileInfo(Host.TemplateFile).DirectoryName;
        var assemblyInfoPath = Path.Combine(pathBase, @"Properties\AssemblyInfo.cs");

        var assemblyInfoSources = File.ReadAllText(assemblyInfoPath);
        var match = assemblyVersionRegex.Match(assemblyInfoSources);
        var version = match.Success 
                ? match.Groups["version"].Value
                : "unknow";
#>

public static class SomeAssemblyInfo
{
    public const string Version = "<#= version #>";
}

So, it reads file AssemblyInfo.cs (or another if you want) get version from it and prepare class SomeAssemblyInfo :

public static class SomeAssemblyInfo
{
    public const string Version = "1.0.0.0";
}

Last thing what you need to do is run this template on build. Here you can find how to do it.