revit-multi-version-configuration

# Revit Multi-Version Configuration A Revit project builds one configuration per supported year. The `Nice3point.Revit.Sdk` derives the framework and the cumulative `REVIT####` / `REVIT####_OR_GREATER` symbols from the active `Debug.RNN` / `Release.RNN` configuration. ## When to use - Declaring or changing which Revit years a project supports. - Writing version-specific code for a real API difference. ## When not to use - Understanding what the SDK sets automatically per version — use `revit-sdk-project-configuration`. - Adding the Revit API assembly references — use `revit-api-references`. ## Workflow ### Step 1: Declare the configuration matrix ```xml <Configurations>Debug.R25;Debug.R26;Debug.R27</Configurations> <Configurations>$(Configurations);Release.R25;Release.R26;Release.R27</Configurations> ``` Mirror the same `Debug.RNN`/`Release.RNN` set in the .slnx/.sln file. ### Step 2: Add or remove a version Add or remove the matching `Debug.RNN` / `Release.RNN` in the solution and the project's `<Configurations>`. For a newly released year, first update the SDK; set `TargetFramework` explicitly only when the SDK is not released with the latest Revit version support or the project uses the preview API package: ```xml <TargetFramework Condition="$(RevitVersion) == '2027'">net10.0-windows7.0</TargetFramework> ``` ### Step 3: Add preprocessor directives for incompatible API Write shared code first. Add a `#if` branch only where the Revit API genuinely differs; keep both branches independently compilable. ```csharp #if REVIT2024_OR_GREATER // API available from Revit 2024 onward #else // legacy API #endif ``` ### Step 4: Verify Restore and build every declared configuration, and run version-specific tests for each branch that changed. ## Validation - [ ] The active solution matrix selects the intended project `Debug.RNN`/`Release.RNN` configurations. - [ ] `#if` branches cover only genuine API differences, and both sides compile. - [ ] Every declared configuration restores and builds. ## Common Pitfalls | Pitfall | Correct approach | |-----------------------------------------------------|---------------------------------------------------| | Editing configurations through the IDE dialog | Edit `<Configurations>` in the `.csproj` by hand. | | A `#if` around code that is identical on both sides | Keep it shared; branch only on real differences. | | Solution and project matrices drifting apart | Keep both lists identical. | | A branch that only compiles for one version | Ensure both `#if` sides build. |