Revit Command to test the Version and Defines

CommandVersion.cs

using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using System;
using System.ComponentModel;

namespace RevitAddin
{
#if DEBUG
    [DisplayName("Revit\rDebug")]
#else
    [DisplayName("Revit\rVersion")]
#endif
    [Description("Show a Window with the Revit VersionName.")]
    [Designer("/UIFrameworkRes;component/ribbon/images/revit.ico")]
    [Transaction(TransactionMode.Manual)]
    public class CommandVersion : IExternalCommand, IExternalCommandAvailability
    {
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elementSet)
        {
            UIApplication uiapp = commandData.Application;
            System.Windows.MessageBox.Show(uiapp.Application.VersionName, GetRevitVersion());
            return Result.Succeeded;
        }
        public bool IsCommandAvailable(UIApplication applicationData, CategorySet selectedCategories)
        {
            return true;
        }
        public static string GetRevitVersion()
        {
#if Revit2017 || REVIT2017
            return "2017";
#elif Revit2018 || REVIT2018
            return "2018";
#elif Revit2019 || REVIT2019
            return "2019";
#elif Revit2020 || REVIT2020
            return "2020";
#elif Revit2021 || REVIT2021
            return "2021";
#elif Revit2022 || REVIT2022
            return "2022";
#elif Revit2023 || REVIT2023
            return "2023";
#elif Revit2024 || REVIT2024
            return "2024";
#elif Revit2025 || REVIT2025
            return "2025";
#else
            return "Undefined";
#endif
        }
    }
}