A simple class to expose the compiled attributes created by GitVersionTask easier to consume in .NET code.

GitVersionInfo.cs

namespace GitVersionInfo   
    /// <summary>
    /// A simple wrapper to make the compiled GitVersionTask variables easily accessible.
    /// 
    /// Here is an example set of values
    /// {
    ///  "Major":1,
    ///  "Minor":3,
    ///  "Patch":0,
    ///  "PreReleaseTag":"unstable.7",
    ///  "PreReleaseTagWithDash":"-unstable.7",
    ///  "BuildMetaData":7,
    ///  "FullBuildMetaData":"7.Branch.develop.Sha.52efa3f2fcd6fac8d4eade31992ea770380ac1d6",
    ///  "MajorMinorPatch":"1.3.0",
    ///  "SemVer":"1.3.0-unstable.7",
    ///  "LegacySemVer":"1.3.0-unstable7",
    ///  "LegacySemVerPadded":"1.3.0-unstable0007",
    ///  "AssemblySemVer":"1.3.0.0",
    ///  "FullSemVer":"1.3.0-unstable.7",
    ///  "InformationalVersion":"1.3.0-unstable.7+Branch.develop.Sha.52efa3f2fcd6fac8d4eade31992ea770380ac1d6",
    ///  "BranchName":"develop",
    ///  "Sha":"52efa3f2fcd6fac8d4eade31992ea770380ac1d6",
    ///  "NuGetVersionV2":"1.3.0-unstable0007",
    ///  "NuGetVersion":"1.3.0-unstable0007",
    ///  "CommitDate":"2015-08-18"
    ///}
    /// </summary>
    public class GitVersionInfo
    {
        /// <summary>
        /// The Major version
        /// </summary>
        public string Major { get; set; }

        /// <summary>
        /// The Minor version
        /// </summary>
        public string Minor { get; set; }

        /// <summary>
        /// The Patch version
        /// </summary>
        public string Patch { get; set; }

        /// <summary>
        /// The pre-release tag
        /// </summary>
        public string PreReleaseTag { get; set; }

        /// <summary>
        /// The pre-release tag with a dash
        /// </summary>
        public string PreReleaseTagWithDash { get; set; }

        /// <summary>
        /// The build meta data value (should be the number of commits ahead of the branch creation)
        /// </summary>
        public string BuildMetaData { get; set; }

        /// <summary>
        /// The full build meta data string (includes the Sha)
        /// </summary>
        public string FullBuildMetaData { get; set; }

        /// <summary>
        /// The Major.Minor.Patch value
        /// </summary>
        public string MajorMinorPatch { get; set; }

        /// <summary>
        /// The semver value
        /// </summary>
        public string SemVer { get; set; }

        /// <summary>
        /// The legacy semver value
        /// </summary>
        public string LegacySemVer { get; set; }

        /// <summary>
        /// The legacy semver value with padded zeros before the metadata value
        /// </summary>
        public string LegacySemVerPadded { get; set; }

        /// <summary>
        /// The Assembly semver value
        /// </summary>
        public string AssemblySemVer { get; set; }

        /// <summary>
        /// The full semver value
        /// </summary>
        public string FullSemVer { get; set; }

        /// <summary>
        /// The full length version that includes all available metadata
        /// </summary>
        public string InformationalVersion { get; set; }

        /// <summary>
        /// The name of the branch the version was generated from
        /// </summary>
        public string BranchName { get; set; }

        /// <summary>
        /// The full length Sha
        /// </summary>
        public string Sha { get; set; }

        /// <summary>
        /// The Nuget version designed to meet the needs of NuGet v2
        /// </summary>
        public string NuGetVersionV2 { get; set; }

        /// <summary>
        /// The nuget version designed to meet the needs of NuGet v3
        /// </summary>
        public string NuGetVersion { get; set; }

        /// <summary>
        /// The date the last committ occurred
        /// </summary>
        public string CommitDate { get; set; }

        /// <summary>
        /// Returns the full semver with the short git hash appended. For example: 1.3.0-unstable.7+12.52efa3f
        /// </summary>
        public string FullSemVerWithShortHash
        {
            get
            {
                return string.Format("{0}.{1}", FullSemVer, Sha.Substring(0, 7));
            }
        }
    }

    /// <summary>
    /// A collection of extensions to help populating a GitVersionInfo instance
    /// </summary>
    public static class GitVersionInfoExtensions
    {
        /// <summary>
        /// Populate all fields from the currently executing assembly.
        /// </summary>
        public static GitVersionInfo PopulateFromExecutingAssembly(this GitVersionInfo instance)
        {
            // This approach has been taken from the GitVersion docs for their
            //  NuGet package
            //      https://gitversion.readthedocs.org/en/latest/usage/#nuget-library
            //
            var assembly = Assembly.GetExecutingAssembly();
            return instance.PopulateFromAssembly(assembly);
        }

        /// <summary>
        /// Populate all fields from an existing assembly. Note, this assembly
        /// must have been built using GitVersionTask!
        /// </summary>
        /// <param name="instance"></param>
        /// <param name="assembly"></param>
        public static GitVersionInfo PopulateFromAssembly(this GitVersionInfo instance, Assembly assembly)
        {
            // This approach has been taken from the GitVersion docs for their
            //  NuGet package
            //      https://gitversion.readthedocs.org/en/latest/usage/#nuget-library
            //
            var assemblyName = assembly.GetName().Name;
            var gitVersionInformationType = assembly.GetType(assemblyName + ".GitVersionInformation");

            instance.Major = (string)gitVersionInformationType.GetField("Major").GetValue(null);
            instance.Minor = (string)gitVersionInformationType.GetField("Minor").GetValue(null);
            instance.Patch = (string)gitVersionInformationType.GetField("Patch").GetValue(null);
            instance.PreReleaseTag = (string)gitVersionInformationType.GetField("PreReleaseTag").GetValue(null);
            instance.PreReleaseTagWithDash = (string)gitVersionInformationType.GetField("PreReleaseTagWithDash").GetValue(null);
            instance.BuildMetaData = (string)gitVersionInformationType.GetField("BuildMetaData").GetValue(null);
            instance.FullBuildMetaData = (string)gitVersionInformationType.GetField("FullBuildMetaData").GetValue(null);
            instance.MajorMinorPatch = (string)gitVersionInformationType.GetField("MajorMinorPatch").GetValue(null);
            instance.SemVer = (string)gitVersionInformationType.GetField("SemVer").GetValue(null);
            instance.LegacySemVer = (string)gitVersionInformationType.GetField("LegacySemVer").GetValue(null);
            instance.LegacySemVerPadded = (string)gitVersionInformationType.GetField("LegacySemVerPadded").GetValue(null);
            instance.AssemblySemVer = (string)gitVersionInformationType.GetField("AssemblySemVer").GetValue(null);
            instance.FullSemVer = (string)gitVersionInformationType.GetField("FullSemVer").GetValue(null);
            instance.InformationalVersion = (string)gitVersionInformationType.GetField("InformationalVersion").GetValue(null);
            instance.BranchName = (string)gitVersionInformationType.GetField("BranchName").GetValue(null);
            instance.Sha = (string)gitVersionInformationType.GetField("Sha").GetValue(null);
            instance.NuGetVersionV2 = (string)gitVersionInformationType.GetField("NuGetVersionV2").GetValue(null);
            instance.NuGetVersion = (string)gitVersionInformationType.GetField("NuGetVersion").GetValue(null);
            instance.CommitDate = (string)gitVersionInformationType.GetField("CommitDate").GetValue(null);

            return instance;
        }
    }
}