Add component dynamically from public object (690414)

Scripting
1

Hi guys,

i’ve got a problem, i tried to search an answer in internet but i didn’t find it.

I’ve got this situation in my project:

public class GameController : MonoBehaviour {

  • public GameObject enemyShip;
  • public Object scriptToAdd; //custom script draggable in unity inspector
  • void Start()
  • {
  • enemyShip.AddComponent(); //How to do this?
  • }

}

Following different topics i found solutions like enemyShip.AddComponent(scriptToAdd.GetType()) but didn’t works ad this message was shown in console: “Can’t add component because ‘MonoScript’ is not derived from Component.”

Can you help me please? i’m a very beginner in Unity, sorry. I’m asking for help because i haven’t found nothing that can help me.

Thanks in advance

2

I think you need to explain what it is you are trying to do, because that looks decidedly odd for a newbie…

3

Thanks LeftyRighty for your reply.

3376632--264897--Senza-titolo-2.jpg

In this game Object I have a list of prefabs (EnemyShips) that instantiate a space ship in my project. I need to give them a beaviour for their movement and i’m trying to add a script (Behaviour) for each EnemyShips. Now i’m trying with one behaviour and if it’ll work will be an array.

The problem is that in my GameController.cs when i try to add the behaviour to a ship it doesn’t work, so actually i don’t know how to do :slight_smile:

i tried to add the component in 2 differents ways, both didn’t work.

i need something like this:

var myEnemy = Instantiate(enemyShip, spawnPosition, spawnRotation);
myEnemy.AddComponent(); //this line is the problem

where “enemyShip” is one ship of the list and “Behaviour” is the object that i choose to add.

I tried to search an answer in this forum and in other places and the only solution that i found was something like this:
myEnemy.AddComponent(Behaviour.GetType());

however it gave me an alert in console with this message:
“Can’t add component because ‘MonoScript’ is not derived from Component.”

How can i do? Is there a way?

4

this is my GameController.cs

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

public class GameController : MonoBehaviour {

public GameObject[] enemyShips;
public Object behaviour;

[Header("SHIPS SPAWN - WAVE 0")]
public int numberEnemy;
public float spawnTimingRatio;

private int waveCounter = 0;
SpawningPositions spawningPositions;

void Start()
{
if (enemyShips.Length != 0)
{
spawningPositions = GetComponent<SpawningPositions>();
StartCoroutine(SpawnShips());
}

}

void Update()
{

}

IEnumerator SpawnShips()
{
GameObject enemyShip = enemyShips[waveCounter];

for (int i = 0; i < numberEnemy; i++)
{
spawningPositions.SpawnCenterRight(enemyShip, behaviour);
Vector3 spawnPosition = new Vector3(-8, 0, 8);
Quaternion spawnRotation = Quaternion.identity;
var myEnemy = Instantiate(enemyShip, spawnPosition, spawnRotation);
myEnemy.AddComponent<behaviour>(); //HERE THE PROBLEM

yield return new WaitForSeconds(spawnTimingRatio);
}
}
}
5

Is the behaviour script a monobehaviour?

6

yes, is it. Thanks

7

Thanks Fabo, i can’t. I need to know if there’s a way to do something like this. Add an AddComponent with a dynamic element

8

Use a ScriptableObject as a prefab asset and inside that have a field for the script you want to add, then point this class to tell the scriptableobject what to do (or just used it as a dumb data reference).

This will give you the modularity you need.

1 Like
9

Maybe something like

public MonoScript behaviour;
...
myEnemy.AddComponent(behaviour.GetClass());
10 
enemyShip.AddComponent<TypeOfYourScript>();

Is all you need. No need to cast, since AddComponent is a generic method. With generic methods you use the type, not the instance. So there is no point in defining the object in the field variable of your script.

Edit: and AddComponent is a method of GameObject. If you need to access the GameObject your custom script or component is attached to, use myComponent.gameObject. That’s a property of Component class.

11

I think you and Fabo are right.

I changed the structure of my project to adapt it at the normal use of the AddComponent method. I thought could be a good thing in my case and something possible to do so i asked you it that sure have a better knowledge than me. Thanks everyone for everything! :slight_smile:

1 Like