Score counter with use of an event system. Please help

Unity Engine
1

Hello,

am trying to implement a simple score counter event. Have a space shooter game and everytime a spawned enemy is killed (one bullet = ine kill) I would like to increment the score. But for some reason th score in the game is not changing/working. Maybe someone could help me with this issue?

In the game I am spawning the enemies (from prefabs) in front of some distance of the player.

GameController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class GameController : MonoBehaviour
{
    public Player3DScript player;
    public GameObject enemyPrefab;

    //score
    int score = 0;
    public Text scoreText;

void Update()
    {
        if (player != null)
        {
            enemySpawnTimer -= Time.deltaTime;

            if (enemySpawnTimer <= 0)
            {
                enemySpawnTimer = enemySpawnInterval;

                GameObject enemyInstance = Instantiate(enemyPrefab);
                enemyInstance.transform.SetParent(transform);
                enemyInstance.transform.position = new Vector3(
                    Random.Range(spawnLevelLimitLeft, spawnLevelLimitRight),
                    -2.5f,
                    player.transform.position.z + enemySpawnDistance
                    );

                enemyInstance.GetComponent<Enemy>().OnKill += OnEnemyKilled;
                Debug.Log("Am in UPDATE Game Controller OnEnemyKilled()");
            }

            foreach (Enemy enemy in GetComponentsInChildren<Enemy>())
            {
                if (player.transform.position.z >= enemy.transform.position.z + 10f)
                    Destroy(enemy.gameObject);
            }
        }
    }

    void OnEnemyKilled()
    {
        score += 1;
        scoreText.text = "Score: " + score;
        Debug.Log("Am in Game Controller OnEnemyKilled() ");
    }
}

Enemy.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Enemy : MonoBehaviour {

    public delegate void KilledHandler();
    public event KilledHandler OnKill;

void OnTriggerEnter2D(Collider2D otherCollider)
    {
        if (otherCollider.tag == "PlayerBullet" || otherCollider.tag == "Player")
        {
            Destroy(gameObject);
            Destroy(otherCollider.gameObject);

            if (OnKill != null)
            {
                Debug.Log(Am in -> onKill()");
                OnKill();
            }
        }
    }
}

The text field is a simple Text object in canvas.

When I start the game I only see the Debug.Log under:
Debug.Log(“Am in UPDATE Game Controller OnEnemyKilled()”);

Also when I kill an enemy, nothing changes. No other Debug.Log uppears.

Any help is really welcome :).

2 
void OnTriggerEnter2D(Collider2D otherCollider)
    {
        if (otherCollider.tag == "PlayerBullet" || otherCollider.tag == "Player")
        {
            Destroy(gameObject);
            Destroy(otherCollider.gameObject);
            if (OnKill != null)
            {
                Debug.Log(Am in -> onKill()");
               OnKill();
           }
       }
   }
}

Not sure if it matters (Perhaps?) but surely you should call the event before destroying the enemy.

3

Have tried it but with no effect :/.

4

Hi @argens

You could also just have a common static event for all enemies, and make other class listen to it. Note, this is not your class, just a demo.

public class Enemy : MonoBehaviour
{
    public static Action<Enemy> EnemyWasDestroyed = delegate { };

    void OnTriggerEnter2D(Collider2D other)
    {
        EnemyWasDestroyed.Invoke(this);
        Destroy(this.gameObject);
    }
}

And then in your other class, that needs to know about enemies:

void OnEnable()
{
    Enemy.EnemyWasDestroyed += EnemyWasDestroyed;
}

void OnDisable()
{
    Enemy.EnemyWasDestroyed -= EnemyWasDestroyed;
}

void EnemyWasDestroyed(Enemy enemy)
{
    Debug.Log("Enemy destroyed:" + enemy.name);
}