C sharp in Godot

Setting up

Follow these instructions and don’t forget to enable auto-reload:
To set up debugging, follow these instructions:
- NOTE (Fri 03/08/2024): perhaps this whole process is simplified with this plugin.
  - Also, I think you can just run “.NET: Generate Assets for Build and Debug” from VSCode to have it create launch.json and tasks.json for you.
- Make sure you put those JSON files in a .vscode folder
- If it says it can’t find the program (which refers to Godot), then make sure you set an environment variable in your shell file and that you reloaded it.
- If you get an issue like No loader found for resource: res://NameOfScript.cs , it could be that the environment variable you set was for Godot rather than Godot_mono. Godot_mono is needed to be able to interpret C#.
To install packages with NuGet, you just need to run something like dotnet add package TwitchLib from the directory with your .csproj file.
To use secrets for your project (e.g. for any API/chat connections), do the following from your project directory:
Terminal window
```
dotnet user-secrets init
dotnet user-secrets set fake-password hunter2
```
- This puts your secret into ls ~/.microsoft/usersecrets/ with the UUID that printed from the init command.
- To read the secrets, you’ll need to run dotnet add package Microsoft.Extensions.Configuration.UserSecrets and then do something like this from the code:
```
using Microsoft.Extensions.Configuration;

var config = new ConfigurationBuilder().AddUserSecrets<Program>().Build();
string username = config["username"];
string password = config["password"];
```
For hot reloading from VSCode on macOS, simply enable csharp.experimental.debug.hotReload (which comes from C# Dev Kit) and make sure you have a .NET SDK > 8.0.100 (e.g. 8.0.303 works). Then, debug through VSCode and it’ll reload changes automatically.

Basics

See my C# notes for any general C# knowledge.
Predefined colors exist in Colors (plural), not Color, e.g. Colors.White.
abstract classes don’t play nice with Godot classes (reference). You may get an error about a script not loading.
Prefer the C# collections where you can since they don’t require marshaling to C++ like the Godot collections do. See this for more information.
Godot’s signals don’t always automatically disconnect (e.g. if you’re using a lambda that captures a variable) (reference). For those, you still need to -= the lambda which you save as a member variable.
- Plus, in VSCode, F12 doesn’t work how you would expect on a Godot signal, so overall, I don’t think they’re really worth using unless you need interoperability with other languages (like GDScript)
- There’s more information in this SO post, and there’s also this Godot proposal to add weak events to C#. In general, if the subscriber (i.e. the thing calling +=) outlives the publisher (i.e. the thing calling someEvent.Invoke()), then you don’t have to do anything.
Rather than use System.Timers.Timer, which will require deferred calls due to threading, just use a Godot timer (AddChild(new Timer())).
- If you don’t want to add a Timer to the scene tree, use this code (await ToSignal(GetTree().CreateTimer(1.0f), SceneTreeTimer.SignalName.Timeout);)

There is no way to Instantiate a scene and call the constructor of the script at the same time (reference). IMO, the next best thing is probably something like this to set private variables in a static factory method:

public partial class Character : Sprite2D
{
    // Prevent construction of Character instances outside of the CreateCharacter method
    private Character() { }

  // Private setter means only this class can set the Town
    public Town Town { get; private set; } = null!;

    public static Character CreateCharacter(Town town)
    {
        PackedScene scene = ResourceLoader.Load<PackedScene>("res://Character.tscn");
        Character c = scene.Instantiate<Character>();
        // Change anything here
        c.Town = town;
        return c;
    }
}

Troubleshooting

VSCode doesn’t show errors/warnings

There are a hundred possible reasons for this. In my particular case, it came down to a casing issue in a .sln file (reference).

Can’t set breakpoints while debugging

If you click in the VSCode gutter while running and get a gray breakpoint, then it’s possible you’re hitting an issue where Godot has the wrong assembly_name in project.godot. For example, I had this folder structure:

Skeleseller
- Game
  - project.godot

…and originally, project.godot had project/assembly_name="Skeleseller". When I changed it to Game, it worked.

An exported build doesn’t work

Perhaps your assembly name doesn’t match your solution/project names (reference)?