Converting GameObject to a custom type

Questions & Answers
1

Hi all,

I’m trying to code a system wherein projectiles, upon colliding with an enemy, deal damage to it and then destroy themselves. Currently, I am trying to do this through the following code, in the script for the projectile itself:

	void OnCollisionEnter2D(Collision2D collision){
		GameObject collidedWith = collision.gameObject;
		if (collidedWith.layer == 10){
			Enemy enemy = (Enemy)collision.gameObject;
			enemy.DamageEnemy(50);
			Destroy(this.gameObject);
		}

Where DamageEnemy is a method within the Enemy class itself, and Layer 10 is the ‘Enemies’ layer.

Now, when I try to load this code, I get the following error:

error CS0030: Cannot convert type UnityEngine.GameObject' to Enemy’

I’ve done a little reading online, but the only solution to a similar problem seemed to involve Instantiating a new object, which won’t work for me, since I don’t want to Instantiate a new object, but rather access the method of an already-existent object (the enemy being hit by the projectile). I was trying to convert collision.gameObject to an Enemy because gameObject does not have a DamageEnemy() method, but clearly this is impossible. The question, then, is how I’m supposed to access the DamageEnemy() method of the object in the collision, when the only way I know of accessing said object returns it in a form that does not have the DamageEnemy() method, and conversion into a form that does have this method isn’t possible.

Thanks.

2

Make Enemy inherit from MonoBehaviour, add it to all the enemies in your project and use collision.gameObject.GetComponent() instead of (Enemy)collison.gameObject. Then you can call whatever methods you want on the enemy.

3

@Kantus
I came here searching for how to cast game object to a class.
I wanted to access the game object without having to add it as a component each time I make changes to my code or updates prefab. The following worked for me…

public Class SomethingElseOtherThanPlayer:MonoBehaviour{

Player player;
    private void Start()
    {
        player= GameObject.FindObjectOfType<Player>();
    }
}