Argument 1: cannot convert from 'method group' to 'UnityAction'

Questions & Answers
1

I have the UnityAction < RaycastHit > onHitEvent:

public class RaycastTrigger: MonoBehaviour
{
    public void ReceiveRaycast(RaycastHit hit)
    {
        RaycastEventTrigger(hit);
    }   
    [Serializable]
    public class  OnRaycastHit: UnityEvent<RaycastHit> { }

    [SerializeField]
    private OnRaycastHit onRaycastHitEvent = new OnRaycastHit();
    public OnRaycastHit onHitEvent { get { return onRaycastHitEvent; } set { onRaycastHitEvent = value; } }

    public void RaycastEventTrigger(RaycastHit hit)
    {
        onHitEvent.Invoke(hit);
    }
}

It invokes when my raycast hits an object with a RaycastTrigger component attached, and passes the raycast hit information onwards. But sometimes I don’t need the raycast information, I just want to trigger a generic event by hitting it with a raycast:

    void Start()
    {
        GetComponent<RaycastTrigger>().onHitEvent.AddListener(MyClick);
    }
    public void MyClick()
    {
        ...
    }

When this code is compiled, though, I get the compile error ‘Argument 1: cannot convert from ‘method group’ to 'UnityAction<RaycastHit>’

If I’m using the editor I can use the event editor in the inspector to select Click() in the dropdown menu under static parameters, so I know it must be possible to do via script. Do I need to add static parameters with something besides for a call to AddListener()? I can always just make Click take (RaycastHit hit) as a parameter and then not use it, but that seems wasteful.

2

Either declare MyClick as follow (even if you don’t need the parameter)

public void MyClick( RaycastHit hit )
{
     
}

Use a lambda method

 void Start()
 {
     GetComponent<RaycastTrigger>().onHitEvent.AddListener( raycastHit => MyClick() );
 }

Or declare another function as callback, which calls MyClick

 void Start()
 {
     GetComponent<RaycastTrigger>().onHitEvent.AddListener( OnHitEvent );
 }

 public void OnHitEvent( RaycastHit raycastHit )
 {
     MyClick();
 }

 public void MyClick()
 {
     ...
 }