Setting Up a Revit Add-In in C# - Step-by-Step Guide

In this guide, we'll walk through the process of setting up a Revit add-in using C#. A Revit add-in allows you to extend the functionality of Autodesk Revit by creating custom tools and features.

Prerequisites

Before we start, ensure that you have the following prerequisites:

• Autodesk Revit (opens in a new tab) installed on your system.
• Visual Studio (opens in a new tab) (2017 or later) with the .NET Desktop Development workload.
• Basic knowledge of C# programming.

Step 1: Create a New Project

1. Open Visual Studio.

2. Click on File > New > Project.

3. Select Class Library (.NET Framework) as the project template.

4. Choose a name for your project (e.g., "RevitAddin").

5. Set the framework to .NET Framework 4.7.2 (or a version compatible with your Revit installation).

6. Click Create.

Step 2: Add References

1. In the Solution Explorer, right-click on your project and select Add > Reference.

2. In the Reference Manager, go to the Browse tab.

3. Browse to the Revit API DLLs. These are typically located in the Revit installation folder (e.g., C:\Program Files\Autodesk\Revit 2022\).

4. Add references to the following DLLs (for Revit 2022 as an example):

   • RevitAPI.dll
   • RevitAPIUI.dll

5. Click OK to add the references.

Step 3: Set Copy Local to False

To avoid conflicts with the Revit installation, set the Copy Local property of the Revit API DLLs to False:

1. In Solution Explorer, select the references you added (e.g., RevitAPI.dll and RevitAPIUI.dll).

2. In the Properties window, set Copy Local to False.

Step 4: Implement Your Add-In

1. Create a C# class that will contain your add-in code.

2. Implement the necessary interfaces and methods as required by the Revit API. For example, you may need to implement the IExternalCommand interface and its Execute method.

3. Write your custom functionality within the Execute method.

Step 5: Build and Deploy

1. Build your project.

2. Locate the compiled DLL in the project's bin\Debug (or bin\Release) folder.

3. Copy the DLL to the Revit add-ins folder, typically located at:

   • C:\ProgramData\Autodesk\Revit\Addins\{RevitVersion}

4. Launch Revit, and your add-in should now be available in the Add-Ins tab.

Conclusion

You've successfully set up a Revit add-in in C#. You can now extend Revit's functionality by implementing custom tools and features within your add-in.

Remember to consult the Revit API documentation (opens in a new tab) for detailed information on available classes and methods.