Help translate C# to JS

Unity Engine
1

Hi Guys,

I have read some code on C# on the forum but I don’t know how to write it in JS. I tryed a few combinations but it did not seems to work:

EventTrigger trigger = UIElement.GetComponent<EventTrigger>();
 EventTrigger.Entry entry = new EventTrigger.Entry();
entry.eventID = EventTriggerType.PointerClick;
entry.callback = new EventTrigger.TriggerEvent();
UnityEngine.Events.UnityAction<BaseEventData> call = new UnityEngine.Events.UnityAction<BaseEventData>(TestFunc);
entry.callback.AddListener(call);
trigger.delegates.Add(entry);

Here’s what I got so far:

var trigger : EventTrigger = obj.AddComponent(EventTrigger);
var entry: EventTrigger.Entry = new EventTrigger.Entry();
entry.eventID = EventTriggerType.PointerClick;
entry.callback = new EventTrigger.TriggerEvent();

This line is my main problem:

UnityEngine.Events.UnityAction<BaseEventData> call = new  UnityEngine.Events.UnityAction<BaseEventData>(TestFunc);

Thanks!

2

C# first line, JS second line:

EventTrigger trigger = UIElement.GetComponent<EventTrigger>();
var trigger = UIElement.GetComponent(EventTrigger);

EventTrigger.Entry entry = new EventTrigger.Entry();
var entry = new EventTrigger.Entry();

entry.eventID = EventTriggerType.PointerClick;
entry.eventID = EventTriggerType.PointerClick;

entry.callback = new EventTrigger.TriggerEvent();
entry.callback = new EventTrigger.TriggerEvent();

UnityEngine.Events.UnityAction<BaseEventData> call = new UnityEngine.Events.UnityAction<BaseEventData>(TestFunc); // This is why type inference was invented....
var call = new UnityEngine.Events.UnityAction.<BaseEventData>(TestFunc);

entry.callback.AddListener(call);
entry.callback.AddListener(call);

trigger.delegates.Add(entry);
trigger.delegates.Add(entry);

–Eric

3

Thank you very much Eric!

But when I ran the code I got an error message about the last line, do you know why?

NullReferenceException: Object reference not set to an instance of an object

For what I understand trigger should be pointing to a valid gameobject and to EventTrigger component. When i print trigger before this last line it says it is an Event Trigger, and on the inspector the eventtrigger has been added to my gameobject.

Thanks again!

4

Not really sure without seeing actual code in a project.

–Eric

5

Eric,

I created a new project with one UI image on the canvas with the name “myobj”.

Then I pretty much had just the code above. But here goes all the code and the same error. Could it be a Bug?

#pragma strict

import UnityEngine.UI;
import System;
import System.Collections.Generic;

import UnityEngine.EventSystems;
import UnityEngine.Events;
import UnityEngine.GameObject;

function Start () {

    var obj = GameObject.Find("myobj");
  
    var events = obj.AddComponent(EventTrigger);
    var trigger = obj.GetComponent(EventTrigger);
    var entry = new EventTrigger.Entry();
    entry.eventID = EventTriggerType.PointerClick;
    entry.callback = new EventTrigger.TriggerEvent();
    var call = new UnityEngine.Events.UnityAction.<BaseEventData>(TestFunc);
    entry.callback.AddListener(call);
    trigger.delegates.Add(entry);


}

function TestFunc(){

    Debug.Log("Hello World");

}
6

Not sure why you’re getting the EventTrigger component twice; that should be:

var trigger = obj.AddComponent(EventTrigger);

Anyway, the null reference is because trigger.delegates is null so you can’t add to it. Not a bug; the same thing would happen in C#. You’d have to initialize it as an EventTrigger.Entry list.

–Eric

7

Eric I tried to look at the forum on how to do it. And also the link about the lists, but after a few failures would help me on the code to initialize it?

My last try was:

var eventTrigger = new List.<EventTrigger>(gameObject.GetComponent(EventTrigger)) ;

Thanks for the great help!

8 
var eventTrigger = new List.<EventTrigger.Entry>();

–Eric

9

Eric, thank you, but I am really sorry to bother you one more time (hope it’s the last).

I tryed to initialize but I think I got a bit confused. I tried this:

// I have changed lines 4, 10 and 11
var obj = GameObject.Find("myobj");
var events = obj.AddComponent(EventTrigger);
var eventTrigger = new List.<EventTrigger.Entry>();
var entry = new EventTrigger.Entry();
entry.eventID = EventTriggerType.PointerClick;
entry.callback = new EventTrigger.TriggerEvent();
var call = new UnityEngine.Events.UnityAction.<BaseEventData>(TestFunc);
entry.callback.AddListener(call);
eventTrigger.Add(entry);
events.delegates.Add(eventTrigger);

But still got the same error… Pls help me one more time this is driving me nuts!!

10

Sorry, I wasn’t paying attention to the “var eventTrigger” thing. That shouldn’t exist; what I said was trigger.delegates is null. That’s what you need to initialize, not make a new variable. Go back to your original code, and initialize trigger.delegates as an EventTrigger.Entry list.

–Eric

11

Thanks!!!

It worked!