Resolved Keeping track of number of objects destroyed after the game is over

I try to get the amount of number of objects destroyed displayed when the game is over, but for some reason the value don`t change.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class BlueWall : MonoBehaviour
6. {
7.  
8.     public static BlueWall Instance { get; private set; }
9.  
10.     [SerializeField] private GameObject blueWall;
11.     [SerializeField] private GameObject blueProjectile;
12.  
13.  
14.     private int blueWallDestroyAmount;
15.  
16.     private void Start()
17.     {
18.         Instance = this;
19.     }
20.     void OnTriggerEnter2D(Collider2D other)
21.     {
22.  
23.         if (other.CompareTag("BlueP"))
24.         {
25.             blueWallDestroyAmount++;
26.             Destroy(gameObject);
27.             Destroy(other.gameObject);
28.         }
29.         else
30.         {
31.          
32.             Destroy(other.gameObject);
33.         }
34.  
35.     }
36.     public int GetBlueWallDestroyAmount()
37.     {
38.         return blueWallDestroyAmount;
39.     }
40. }
41.  

Code (CSharp):

1. using System;
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class IGameManager : MonoBehaviour
7. {
8.     public static IGameManager Instance { get; private set; }
9.  
10.     public event EventHandler OnStateChanged;
11.    private enum State
12.     {
13.         WaintingToStart,
14.         CountdownToStart,
15.         GamePlaying,
16.         GameOver,
17.     }
18.  
19.     private State state;
20.     private float waitingToStartTimer = 1f;
21.     private float countdownToStartTimer = 3f;
22.  
23.     private void Awake()
24.     {
25.         Instance = this;
26.         state = State.WaintingToStart;
27.     }
28.  
29.     private void Update()
30.     {
31.         switch (state)
32.         {
33.             case State.WaintingToStart:
34.                 waitingToStartTimer -= Time.deltaTime;
35.                 if(waitingToStartTimer < 0f)
36.                 {
37.                     state = State.CountdownToStart;
38.                     OnStateChanged?.Invoke(this, EventArgs.Empty);
39.                 }
40.                 break;
41.  
42.             case State.CountdownToStart:
43.                 countdownToStartTimer -= Time.deltaTime;
44.                 if(countdownToStartTimer < 0f)
45.                 {
46.                     state = State.GamePlaying;
47.                     OnStateChanged?.Invoke(this, EventArgs.Empty);
48.                 }
49.  
50.                 break;
51.             case State.GamePlaying:
52.                 state = State.GamePlaying;
53.                 if(Player.Instance.gameOver == true)
54.                 {
55.                     state = State.GameOver;
56.                 }
57.  
58.                 OnStateChanged?.Invoke(this, EventArgs.Empty);
59.                 break;
60.             case State.GameOver:
61.              
62.              
63.                     state = State.GameOver;
64.              
65.                 OnStateChanged?.Invoke(this, EventArgs.Empty);
66.              
67.                 break;
68.              
69.         }
70.         Debug.Log(state);
71.     }
72.     public bool IsGamePlaying()
73.     {
74.         return state == State.GamePlaying;
75.     }
76.  
77.     public bool IsCountdownToStartActive()
78.     {
79.         return state == State.CountdownToStart;
80.     }
81.  
82.     public float GetCountdownToStartTimer()
83.     {
84.         return  countdownToStartTimer;
85.     }
86.  
87.     public bool IsGameOver()
88.     {
89.         return state == State.GameOver;
90.     }
91. }
92.  

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using TMPro;
5.  
6. public class GameOverUI : MonoBehaviour
7.  
8.  
9. {
10.     [SerializeField] private TextMeshProUGUI blueWallDestroyText;
11.     [SerializeField] private TextMeshProUGUI redWallDestroyText;
12.     [SerializeField] private TextMeshProUGUI greenWallDestroyText;
13.     [SerializeField] private TextMeshProUGUI yellowWallDestroyText;
14.     private void Start()
15.     {
16.         IGameManager.Instance.OnStateChanged += IGameManager_OnStateChanged;
17.  
18.        // Hide();
19.     }
20.  
21.  
22.     private void IGameManager_OnStateChanged(object sender, System.EventArgs e)
23.     {
24.         if (IGameManager.Instance.IsGameOver())
25.         {
26.             Show();
27.  
28.             blueWallDestroyText.text = BlueWall.Instance.GetBlueWallDestroyAmount().ToString();
29.             yellowWallDestroyText.text = YellowWall.Instance.GetYellowWallDestroyAmount().ToString();
30.         }
31.       //  else
32.       //  {
33.         //    Hide();
34.        // }
35.     }
36.  
37.  
38.     private void Show()
39.     {
40.         gameObject.SetActive(true);
41.     }
42.   //  private void Hide()
43.    // {
44.       //  gameObject.SetActive(false);
45.    // }
46. }
47.  
48.  

 

Every time you increment blueWallDestroyAmount you also destroy the wall itself (that holds the value) so the value is of course lost.

Code (CSharp):

1.  
2. if (other.CompareTag("BlueP"))
3. {
4.             blueWallDestroyAmount++;
5.             Destroy(gameObject); //<-- you're destroying the wall gameObject here.
6.             Destroy(other.gameObject);
7. }

In fact accessing BlueWall.Instance.GetBlueWallDestroyAmount() after the value has been incremented will probably result in a NullRefException, since the Instance itself has been destroyed.

 

I know that Im destroying that game object there...but what should I do to have the number of destroyed items displayed when the game is over? I dont get a NullRefExeption but the number of destroyed objects doesnt change when I destroy them, but when the player is destroyed, the value change to 0.

 

Simply don't store the number of destroyed items in the object you're destroying (for obvious reasons: once the object doesn't exist anymore neither does the count), store it elsewhere.

Btw, if you want to have more than one BlueWall in your game -I strongly suspect you do- you shouldn't use a singleton pattern like you seem to be doing.

Singleton assumes there will only ever be a single instance of BlueWall in the game. Worse still, you singleton is bugged since it doesn't enforce a single instance and BlueWall.Instance will return whichever BlueWall instance had its Start() method called last, so in practice you're getting one instance completely at random.