Cannot hook up an event

Question

I'm trying to install event from class BasicLaser in a class BlueShip, so basically this event will be fired every n number of time units.
Here is the class BlueShip which is "connected" to a sprite in unity:

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

    public class BlueShip : MonoBehaviour
    {
        enum LaserTypes { BASIC_LASER };
        private float speed_ = 100f;
        private List<GameObject> laser_ = new List<GameObject>();
        private GameObject currentLaser_;
        private Transform transform_;
        private Vector3 currentPosition_;
        private bool isElapsed_ = true;
        // Use this for initialization
        void Start()
        {
            transform_ = transform;
            /*Basic laser is the default and it's guaranteed to be installed at the beginning of the game*/
            laser_.Add((GameObject)Resources.Load("BasicLaser"));
            currentLaser_ = laser_[(int)LaserTypes.BASIC_LASER];
            laser_[0].GetComponent<BasicLaser>().timerElapsed += new TimerElapsed (BasicLaser_timerElapsed);    
//HERE I'M adding observer to this event but look for line named *2 in class BasicLaser


        }  

        public void BasicLaser_timerElapsed(object sender, EventArgs e)
        {/*this is supposed to react to event timerElapsed in BasicLaser*/
            isElapsed_ = true;
        }


        // Update is called once per frame
        void Update()
        {
            var amtToMove = Input.GetAxis("Horizontal") * speed_ * Time.deltaTime;
            transform_.Translate(Vector3.right * amtToMove);
            /*Those below set the position for laser to be instantiated at*/
            currentPosition_.x = transform_.position.x;
            currentPosition_.y = transform_.position.y + (this.transform.localScale.y / 2) + currentLaser_.transform.localScale.y;
            currentPosition_.z = transform_.position.z;


            if (Input.GetKeyDown(KeyCode.UpArrow))
            {
                if (isElapsed_)
                {
                    var t = Instantiate(laser_[(int)LaserTypes.BASIC_LASER], currentPosition_, Quaternion.identity);
                    isElapsed_ = false;
                }

            }

        }
    }


//BasicLaser class  which is "connected" to a BasicLaser prefab in unity
    using UnityEngine;
    using System.Collections;
    using System.Diagnostics;
    using System;
    public delegate void TimerElapsed(object sender,EventArgs e);
        public class BasicLaser : MonoBehaviour
        {

            private float speed_ = 500f;
            private static uint frequency_ = 2;//the frequency with which this laser can be fired
            private static Stopwatch stopWatch_ = new Stopwatch();

            public event TimerElapsed timerElapsed;//HERE IS THE EVENT

            public uint Frequency
            {
                get { return frequency_; }
                set { frequency_ = value; }
            }

            private Transform transform_;
            // Use this for initialization
            void Start()
            {
                transform_ = transform;
                stopWatch_.Start();

            }



            // Update is called once per frame
            void Update()
            {
                var amtToMove = speed_ * Time.deltaTime;
                transform_.Translate(Vector3.up * amtToMove);
            var t = stopWatch_.Elapsed.Milliseconds;
                if (t > frequency_)
                {
                    stopWatch_ = new Stopwatch();
                    stopWatch_.Start();
                    if (timerElapsed != null)//*2 THIS IS ALWAYS NULL!!!  
     even though I've hooked it in BlueShip class, what's going on?

                    {
                        timerElapsed(this, EventArgs.Empty);//raises the event
                    }
                }

                if (transform.position.y >= Screen.height)
                {
                    Destroy(gameObject);
                }
            }
        }

Answer 1

Please check the Console or log file and tell us if you're getting any errors in BlueShip's Start method. Also use Debug.Log and look in the log files to see if any of the objects are null when they shouldn't be. (e.g. Debug.Log (currentLaser_);)

I think this is your problem:

(GameObject)Resources.Load("BasicLaser")

This gives your the object in your Assets/Resources folder called "BasicLaser", which (assuming it exists at all) is probably a prefab. The GameObject you can get here is not the same as a GameObject you might have in the scene. You should either be instantiating this prefab and then attaching to that instantiated object's event, or you should be referring to a BasicLaser that already exists in your scene, by changing the line to this: laser_.Add((GameObject)GameObject.Find ("BasicLaser")); (if the name of the GameObject with the BasicLaser component is "BasicLaser").