.. _doc_c_sharp: C# basics ========= Introduction ------------ .. warning:: C# support is a new feature available since Godot 3.0. As such, you may still run into some issues, or find spots where the documentation could be improved. Please report issues with C# in Godot on the `engine GitHub page `_, and any documentation issues on the `documentation GitHub page `_. This page provides a brief introduction to C#, both what it is and how to use it in Godot. Afterwards, you may want to look at :ref:`how to use specific features `, read about the :ref:`differences between the C# and the GDScript API ` and (re)visit the :ref:`Scripting section ` of the step-by-step tutorial. C# is a high-level programming language developed by Microsoft. In Godot, it is implemented with the Mono 6.x .NET framework, including full support for C# 8.0. Mono is an open source implementation of Microsoft's .NET Framework based on the ECMA standards for C# and the Common Language Runtime. A good starting point for checking its capabilities is the `Compatibility `_ page in the Mono documentation. .. note:: This is **not** a full-scale tutorial on the C# language as a whole. If you aren't already familiar with its syntax or features, see the `Microsoft C# guide `_ or look for a suitable introduction elsewhere. Setting up C# for Godot ----------------------- Windows (Visual Studio) ~~~~~~~~~~~~~~~~~~~~~~~ Download and install the latest version of `Visual Studio `_ (*not* Visual Studio Code), which contains utilities required to use C# in Godot. If you don't plan on using the Visual Studio IDE, you can download just the `Visual Studio Build Tools `_ instead. Make sure you at least have the .NET Framework 4.5 targeting pack installed, you can get it using any of the installers mentioned above inside the "Individual components" tab. Windows (JetBrains Rider) ~~~~~~~~~~~~~~~~~~~~~~~~~ JetBrains Rider comes with bundled MSBuild, so nothing extra is required. Make sure to set the following preferences: - In Godot's Editor Settings: - Set **Mono External Editor** to **JetBrains Rider**. - set **Mono Build Tool** to **JetBrains Mono**. - In Rider: - Set **MSBuild version** to either **Bundled with Rider** or **.NET Core**. - Install the **Godot support** plugin. macOS and Linux ~~~~~~~~~~~~~~~ Download and install the latest version of the `Mono SDK `_. As of Godot 3.1 beta 3, the version number doesn't matter since Godot bundles its own Mono 5.18 installation. We only need the Mono installation for NuGet and MSBuild which are required to use C# in Godot. .. note:: To download Mono on macOS, use the "Stable Channel" link from the `Mono Downloads Page `_. The Visual Studio channel is an earlier version of Mono and will not work. Additional notes ~~~~~~~~~~~~~~~~ Your Godot version must have Mono support enabled, so make sure to download the **Mono version** of Godot. If you are building Godot from source, make sure to follow the steps to enable Mono support in your build as outlined in the :ref:`doc_compiling_with_mono` page. In summary, you must have installed Visual Studio or Mono (depending on your operating system) **and** the Mono-enabled version of Godot. Configuring an external editor ------------------------------ C# support in Godot's script editor is minimal. Consider using an external IDE or editor, such as `Visual Studio Code `_ or MonoDevelop. These provide autocompletion, debugging, and other useful features for C#. To select an external editor in Godot, click on **Editor → Editor Settings** and scroll down to **Mono**. Under **Mono**, click on **Editor**, and select your external editor of choice. Godot currently supports the following external editors: - Visual Studio 2019 - Visual Studio Code - MonoDevelop - Visual Studio for Mac - JetBrains Rider .. note:: If you are using Visual Studio Code, ensure you download and install the `C# extension `_ to enable features like syntax highlighting and IntelliSense. .. note:: If you are using Visual Studio 2019, you must follow the instructions found in the `:ref:doc_c_sharp_configuring_vs_2019_for_debugging` section below. Creating a C# script -------------------- After you successfully set up C# for Godot, you should see the following option when selecting **Attach Script** in the context menu of a node in your scene: .. image:: img/attachcsharpscript.png Note that while some specifics change, most concepts work the same when using C# for scripting. If you're new to Godot, you may want to follow the tutorials on :ref:`doc_scripting` at this point. While some places in the documentation still lack C# examples, most concepts can be transferred easily from GDScript. Project setup and workflow -------------------------- When you create the first C# script, Godot initializes the C# project files for your Godot project. This includes generating a C# solution (``.sln``) and a project file (``.csproj``), as well as some utility files and folders (``.mono`` and ``Properties/AssemblyInfo.cs``). All of these but ``.mono`` are important and should be committed to your version control system. ``.mono`` can be safely added to the ignore list of your VCS. When troubleshooting, it can sometimes help to delete the ``.mono`` folder and let it regenerate. Example ------- Here's a blank C# script with some comments to demonstrate how it works. .. code-block:: csharp using Godot; using System; public class YourCustomClass : Node { // Member variables here, example: private int a = 2; private string b = "textvar"; public override void _Ready() { // Called every time the node is added to the scene. // Initialization here. GD.Print("Hello from C# to Godot :)"); } public override void _Process(float delta) { // Called every frame. Delta is time since the last frame. // Update game logic here. } } As you can see, functions normally in global scope in GDScript like Godot's ``print`` function are available in the ``GD`` class which is part of the ``Godot`` namespace. For a list of methods in the ``GD`` class, see the class reference pages for :ref:`@GDScript ` and :ref:`@GlobalScope `. .. note:: Keep in mind that the class you wish to attach to your node should have the same name as the ``.cs`` file. Otherwise, you will get the following error and won't be able to run the scene: *"Cannot find class XXX for script res://XXX.cs"* General differences between C# and GDScript ------------------------------------------- The C# API uses ``PascalCase`` instead of ``snake_case`` in GDScript/C++. Where possible, fields and getters/setters have been converted to properties. In general, the C# Godot API strives to be as idiomatic as is reasonably possible. For more information, see the :ref:`doc_c_sharp_differences` page. .. warning:: You need to (re)build the project assemblies whenever you want to see new exported variables or signals in the editor. This build can be manually triggered by clicking the word **Mono** at the bottom of the editor window to reveal the Mono panel, then clicking the **Build Project** button. You will also need to rebuild the project assemblies to apply changes in "tool" scripts. Current gotchas and known issues -------------------------------- As C# support is quite new in Godot, there are some growing pains and things that need to be ironed out. Below is a list of the most important issues you should be aware of when diving into C# in Godot, but if in doubt, also take a look over the official `issue tracker for Mono issues `_. - Writing editor plugins is possible, but it is currently quite convoluted. - State is currently not saved and restored when hot-reloading, with the exception of exported variables. - Attached C# scripts should refer to a class that has a class name that matches the file name. - There are some methods such as ``Get()``/``Set()``, ``Call()``/``CallDeferred()`` and signal connection method ``Connect()`` that rely on Godot's ``snake_case`` API naming conventions. So when using e.g. ``CallDeferred("AddChild")``, ``AddChild`` will not work because the API is expecting the original ``snake_case`` version ``add_child``. However, you can use any custom properties or methods without this limitation. As of Godot 3.2.2, exporting Mono projects is supported for desktop platforms (Linux, Windows and macOS), Android, HTML5, and iOS. The only platform not supported yet is UWP. Performance of C# in Godot -------------------------- According to some preliminary `benchmarks `_, the performance of C# in Godot — while generally in the same order of magnitude — is roughly **~4×** that of GDScript in some naive cases. C++ is still a little faster; the specifics are going to vary according to your use case. GDScript is likely fast enough for most general scripting workloads. C# is faster, but requires some expensive marshalling when talking to Godot. Using NuGet packages in Godot ----------------------------- `NuGet `_ packages can be installed and used with Godot, as with any C# project. Many IDEs are able to add packages directly. They can also be added manually by adding the package reference in the ``.csproj`` file located in the project root: .. code-block:: xml :emphasize-lines: 2 11.0.2 ... .. note:: By default, tools like NuGet put ``Version`` as an attribute of the ```PackageReference``` Node. **You must manually create a Version node as shown above.** This is because the version of MSBuild used requires this. (This will be fixed in Godot 4.0.) Whenever packages are added or modified, run ``nuget restore`` (*not* ``dotnet restore``) in the root of the project directory. To ensure that NuGet packages will be available for msbuild to use, run: .. code-block:: none msbuild /t:restore Profiling your C# code ---------------------- - `Mono log profiler `_ is available for Linux and macOS. Due to a Mono change, it does not work on Windows currently. - External Mono profiler like `JetBrains dotTrace `_ can be used as described `here `_. .. _doc_c_sharp_configuring_vs_2019_for_debugging: Configuring VS 2019 for debugging --------------------------------- .. note:: Godot has built-in support for workflows involving several popular C# IDEs. Built-in support for Visual Studio will be including in future versions, but in the meantime, the steps below can let you configure VS 2019 for use with Godot C# projects. 1. Install VS 2019 with ``.NET desktop development`` and ``Desktop development with C++`` workloads selected. 2. **Ensure that you do not have Xamarin installed.** Do not choose the ``Mobile development with .NET`` workload. Xamarin changes the DLLs used by MonoDebugger, which breaks debugging. 3. Install the `VSMonoDebugger extension `_. 4. In VS 2019 --> Extensions --> Mono --> Settings: - Select ``Debug/Deploy to local Windows``. - Leave ``Local Deploy Path`` blank. - Set the ``Mono Debug Port`` to the port in Godot --> Project --> Project Settings --> Mono --> Debugger Agent. - Also select ``Wait for Debugger`` in the Godot Mono options. `This Godot Addon `_ may be helpful. 5. Run the game in Godot. It should hang at the Godot splash screen while it waits for your debugger to attach. 6. In VS 2019, open your project and choose Extensions --> Mono --> Attach to Mono Debugger. Configuring Visual Studio Code for debugging -------------------------------------------- To configure debugging, open Visual Studio Code and download the Mono Debug extension from Microsoft and the Godot extension by Ignacio. Then open the Godot project folder in VS Code. Go to the Run tab and click on **create a launch.json file**. Select **C# Godot** from the dropdown menu. Now, when you start the debugger in VS Code your Godot project will run.