How do you make it so a message prints when you enter a Area2D in GoDot C#

dokkizab

Ive been frustrated over this for a couple of hours and I have not seen many people post about this so I will be the first lol. I have this really simple piece of code attached to my NPC parent node called "cherri", the scene is named cherri as well. Here is what the hierarchy looks like:

I also have a scene called mainchar that has a hierarchy which also looks like this:

My code is inside of the Area2D that is in the cherri scene called "TriggerArea" and this is what the code looks like:

I am getting no errors through the code but it seems when I enter the TriggerArea it just doesn't end up printing in the console to check if it is working. I was getting frustrated because I looked it up on the godot documentation so that it can tell me how to do an Area2D in C# but it only shows how to do it in GDScript and when I looked at youtube videos or other forums about it, I haven't found anything related to this exact situation or it is something too advanced for my knowledge. Plz, much help is appriecated.

kuligs2

dokkizab the question is does it really get triggered when th ebody enters?

how about when you do not check for "is Player" and let anybody trigger it? If that works or does not you can debug this from there...

Makes sure you connect the void to the signal that triggers on body enters.. not sure how it works in windows lang but in gscript you use:

Check this https://docs.godotengine.org/en/stable/getting_started/step_by_step/signals.html#complete-script Switch between bill-lang and gscript to see the timeout signal being conencted

dokkizab

kuligs2 Okay so I changed the code to "if (body != null) and that also didn't work either. I tried putting the player below the cherri node and that also didn't work. I tried it in the cherri scene as well and that also didn't work. I think it is either code related or I am missing something I was supposed to turn on or use in the inspector or the collision layer.

DaveTheCoder

dokkizab didn't work

Are you sure that the body_entered signal is connected to the desired method, as kuligs2 pointed out?

If you put a print statement at the beginning of the function, does it show that the function was called?

If you're not sure, there are Signal class methods that tell you whether a signal is connected.
https://docs.godotengine.org/en/4.5/classes/class_signal.html

kuligs2

DaveTheCoder as much as we want to blame th enew guy here, the documentation does not give a precise example that works in his case..

https://docs.godotengine.org/en/4.5/tutorials/physics/using_area_2d.html

it just shows the function and not how it is connected..

the best example would be timer here:


func _ready():
	var timer = get_node("Timer")
	timer.timeout.connect(_on_timer_timeout)

public override void _Ready()
{
    var timer = GetNode<Timer>("Timer");
    timer.Timeout += OnTimerTimeout;
}

Notice that the timer.timeout the timeout is the signal and it connects to a function _on_timer_timeout

in billang i see the signals are capitalized timer.Timeout += OnTimerTimeout;

dokkizab

kuligs2 Alr I fixed it! Here is the fixed code:

using Godot;
using System;

public partial class TriggerArea : Area2D
{
public override void _Ready()
{
GD.Print("TriggerArea script loaded.");

    // Connect signal (Godot 4 way)
    BodyEntered += OnTriggerAreaBodyEntered;
}

private void OnTriggerAreaBodyEntered(Node2D body)
{
    if (body is Player)
    {
        GD.Print("Player entered the NPC area!");
    }
}

}

Just as a bonus curiosity thing, why does BodyEntered += OnTriggerAreaBodyEntered; connect the signal? How does that work?

dokkizab

kuligs2 Sorry, I don't wanna ask for too much here lol. But what is billang?

kuligs2

dokkizab not sure but C# is retarded with syntax.. hard to read and understand at a glance.. gdscript in that regard is more readable..

well as per godot, signals need to be connected to functions. so when signal triggers - body_entered - then a function plays out. in billang it is not that obvious because of the stupid syntax. in gdscript its with a helper signal.connect(myfunction)

Idk.. its like asking why does chicken lay eggs but not produce milk.. it is what it is.

Toxe

dokkizab Just as a bonus curiosity thing, why does BodyEntered += OnTriggerAreaBodyEntered; connect the signal? How does that work?

Well, I don't use or know C# but my guess would be that the += operator is overloaded for the signal class and this is basically just syntactic sugar for something like BodyEntered.connect(OnTriggerAreaBodyEntered).

xyz

dokkizab With C# in Godot, signals are implemented as C# events. As already mentioned they have += operator overloaded to register event handlers (and -= to unregister). Those are equivalent to GDScript Singal::connect() and Signal::disconnect() functions.

kuligs2

dokkizab bill gates language, a.k.a billy boi, a.k.a C#