Support multiple versions of Revit in invokebuttons (dll projects, Visual Studio)

Revit API
10

@AndreaTas, I have approached the same scenario similarly too, and have put together a sample project for others to use incase someone else faces a similar sitiuation, here:

A few things to note:

  1. you can make use of the dynamic object type to handle the varying API return types where needed within your executing command classes.
  2. I am using the Costura.Fody nuget package to utilise the version-specific APIs as embedded resources within my main compiled library and avoid missing references at runtime invocation of the commands.
  3. If you’re majorly writing your command for newer versions of the API, and need to support small functionality for older versions, then you only need the version-specific library project for the older API and wrap its execution into a conditional syntax that ensures it will only get triggered by Revit version checks.

Here are code samples from the repo:

image
image1920×1029 189 KB

The Main executing Command class

#region Namespaces
using Autodesk.Revit.ApplicationServices;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using pyApi18;
using pyApi21;
#endregion

namespace pyRevitGirihXPlayground
{
    [Transaction(TransactionMode.Manual)]
    public class Command : IExternalCommand
    {
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            UIApplication uiapp = commandData.Application;
            UIDocument uidoc = uiapp.ActiveUIDocument;
            Application app = uiapp.Application;
            Document doc = uidoc.Document;
            int.TryParse(app.VersionNumber, out int version);

            string[] unitsNames;
            dynamic unitsTypes;
            dynamic currUnitType;

            if (version <= 2020)
            //unitsTypes is DisplayUnitType[] / currUnitType is DisplayUnitType
            { unitsNames = Helpers2018.VersionControl.GetUnitChoices(doc, out unitsTypes, out currUnitType); }
            else
            //unitsTypes is ForgeTypeId[] / currUnitType is ForgeTypeId
            { unitsNames = Helpers2021.VersionControl.GetUnitChoices(doc, out unitsTypes, out currUnitType); }

            TaskDialog.Show("Available Units", "Available Unit Options:\n" + string.Join("\n", unitsNames));
            if (version <= 2020)
            {
                TaskDialog.Show("Current Unit", $"Current Document Units:\n{currUnitType}");
                foreach (var unit in unitsTypes) TaskDialog.Show("Unit Option Type", $"{unit.GetType()}:\n{unit}");
            }
            else 
            /*even though the "ForgeTypeId.TypeId" property is only available in 2021+ APIs, 
            * it will still work fine in 2020 and earlier versions as this code will not be executed 
            * for 2020 and earlier versions; You MUST build the below code against 2021+ APIs 
            * to compile it without errors.*/
            {
                TaskDialog.Show("Current Unit", $"Current Document Units:\n{currUnitType.TypeId}");
                foreach (var unit in unitsTypes) TaskDialog.Show("Unit Option Type", $"{unit.GetType()}:\n{unit.TypeId}");
            }

            return Result.Succeeded;
        }
    }
}

the 2018-2020 API supporting methods class library:

#region Namespaces
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using System.Linq;
#endregion

namespace pyApi18
{
    public static class Helpers2018
    {
        public static class VersionControl
        {
            public static string[] GetUnitChoices(Document doc, out dynamic UnitOptions, out dynamic CurrentUnit)
            {
                TaskDialog.Show("Dynamic Version Test", "Helpers2018!");
                
                DisplayUnitType currentUnit = doc.GetUnits().GetFormatOptions(UnitType.UT_Length).DisplayUnits;
                DisplayUnitType[] unitOptions = new DisplayUnitType[]
                { DisplayUnitType.DUT_METERS, DisplayUnitType.DUT_CENTIMETERS, DisplayUnitType.DUT_MILLIMETERS, DisplayUnitType.DUT_DECIMAL_FEET };

                string[] UnitsNames = unitOptions.Select(i => i.ToString()).ToArray();
                UnitOptions = unitOptions;
                CurrentUnit = currentUnit;
                return UnitsNames;
            }
        }
    }
}

the 2021-2024 API supporting methods class library:

#region Namespaces
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using System.Linq;
#endregion

namespace pyApi21
{
    public static class Helpers2021
    {
        public static class VersionControl
        {
            public static string[] GetUnitChoices(Document doc, out dynamic UnitOptions, out dynamic CurrentUnit)
            {
                TaskDialog.Show("Dynamic Version Test", "Helpers2021!");

                ForgeTypeId currentUnit = doc.GetUnits().GetFormatOptions(SpecTypeId.Length).GetUnitTypeId();
                ForgeTypeId[] unitOptions = new ForgeTypeId[] 
                { UnitTypeId.Meters, UnitTypeId.Centimeters, UnitTypeId.Millimeters, UnitTypeId.Feet };

                string[] UnitsNames = unitOptions.Select(i => i.TypeId).ToArray();
                UnitOptions = unitOptions;
                CurrentUnit = currentUnit;
                return UnitsNames;
            }
        }
    }
}

Also, worth noting, the sample repo has:

  • Boilerplate for the invoke commands extension library folders and .invokebutton setup with a root-level lib folder

    image
    image379×727 19.1 KB

  • The VisualStudio project automatically copies the compiled solution to the extension’s lib folder with post-build events

  • The VisualStudio project conditionally switches references to the Revit API/UI from 2018-2024 based on the build configuration options (debug_2018, debug_2019, …etc) for ease of API reference testing
    and compilation against the version of choice.

    image
    image738×824 23.6 KB

@AndreaTas, @Jean-Marc, and all, please feel free to improve and reshare with a PR.

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