Help with Restoring Health

Unity Engine
,
1

I’m trying to implement a checkpoint system in my game, where when a player clicks on the checkpoint, they will have their health refilled to full. However, whenever I try to test that part of the code, it gives me a Null Reference Exception and the HealthSlider becomes null. It’s assigned in the inspector so I don’t know what’s causing this. Every other part of the code seems to be working.

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


public class PlayerHealth : MonoBehaviour
{

    public int startHealth = 2;

    public int currentHealth;

    public Slider HealthSlider;

    public AudioClip hurtClip;
    public AudioClip deathClip;

    public Animator anim;

    public AudioSource playerAudio;

    public PlayerMovement pm;

    bool isDead;

    bool damaged;


    // Start is called before the first frame update
    void Awake()
    {
        anim = GetComponent<Animator>();
        playerAudio = GetComponent<AudioSource>();
        pm = GetComponent<PlayerMovement>();

        currentHealth = startHealth;

    }

    // Update is called once per frame
    void Update()
    {
        if (damaged)
        {
            playerAudio.clip = hurtClip;
            playerAudio.Play();
            damaged = false;
        }

        HealthSlider.value = currentHealth;
    }

    public void TakeDamage(int amount)
    {
        damaged = true;

        currentHealth -= amount;

        if (currentHealth <= 0 && !isDead)
        {
            Death();
        }
    }

    void Death()
    {
        isDead = true;

        anim.SetTrigger("Die");

        playerAudio.clip = deathClip;
        playerAudio.Play();

        pm.enabled = false;
    }

    public void ResetHealth()
    {
        currentHealth = startHealth;
        print(HealthSlider);
        HealthSlider.value = currentHealth;
    }
}
2

Are both the PlayerHealth object and the HealthSlider object in the scene? Or is one of them a prefab, or Instantiated from a prefab?

3

Both of them are in the scene as objects.

4

How do you call ResetHealth? From a UI button? From another script?

5

From an OnExecute() Event

6

My question is basically, where are you getting the PlayerHealth reference from to call ResetHealth?

7

It’s in the same script

8

Where? I don’t see it above.

9

I’m confused. Are you asking what I’m doing to call the method to run?

10

Yes

11

6173476--675721--upload_2020-8-5_17-37-16.png
6173476--675721--upload_2020-8-5_17-37-16.png821×1001 71.1 KB

I’m using Pixel Crushers’ Dialogue System to call it when I click on the checkpoint. The alert is showing up so the trigger is activating.

12

So that John object from the screenshot. Is that your player from the scene, or is it a prefab?

13

It’s from a prefab.

14

So if it’s referring to the prefab, that’s not your player instance that’s in the scene at runtime, right?

15

I guess not. It’s instantiated from the prefab, though.