Power Up Slider Help!

Hi! I am a Unity& code beginner. I am developing a simple 2D platform for a class and I am running into difficulty creating a slider that is affected when my player runs through a power-up. I have a script attached to my power-up that destroys the power-up when it is ran through. I also have a script attached to my slider. Now the issue I am experiencing is how to link the slider to the action of the player colliding with a power-up. I want the slider to increase in value every time my player collides with a power-up. Can anyone tell me what I am doing wrong? Here is the code I have so far:

Power-up script:

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

public class Collectible : MonoBehaviour
{
private void OnTriggerEnter2D(Collider2D other)
{
if (other.tag == "Player")
{
Destroy(this.gameObject);
}

}
}


Slider Script:

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

public class HealthBar : MonoBehaviour
{
public Slider slider;
public void SetMaxHealth(int health)
{
slider.maxValue = health;
slider.value = health;
}
public void SetHealth(int health)
{
slider.value = health;
}

}

 

you can use transform.gameObject.GetComponent<>() to grab the object that is a parent of the Collider2D other.

I added a SubtractHealth() function to update the slider value. To increase, you can use AddHealth()

Alternatively, you can use GameObject.Find(" ") to access the object such as a player to obtain its components

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class Collectible : MonoBehaviour
7. {
8.    private void OnTriggerEnter2D(Collider2D other)
9.   {
10.     if (other.tag == "Player") {
11.        other.transform.gameObject.GetComponent<HealthBar>().SubtractHealth();    
12.     }
13.   }
14. }
15.  
16.  
17. //Slider Script:
18.  
19. using System.Collections;
20. using System.Collections.Generic;
21. using UnityEngine;
22. using UnityEngine.UI;
23.  
24. public class HealthBar : MonoBehaviour
25. {
26.   public Slider slider;
27.  
28.   public void SetMaxHealth(int health)
29.   {
30.     slider.maxValue = health;
31.     slider.value = health;
32.   }
33.  
34. public void SetHealth(int health)
35. {
36.    slider.value = health;
37. }
38.  
39. public void SubtractHealth() {
40.    slider.value -= 0.1f;
41. }
42. }

 

Thank you! I tried this but when I try it out in game mode, it says "object reference not set to the instance of an object" and the slider does not move. Is there something I should add?

 

"also have a script attached to my slider. Now the issue I am experiencing is how to link the slider to the action of the player colliding with a power-up"

is the script class HealthBar attached to the player? and the slider is not "None" in inspector?

 

The healthBar is attached to my UI slider and is named HealthBar in the inspector

 

Sorry, first time posting in the forums, wasn't sure.

 

I recommend that the best solution is to attach the HealthBar script to the player. Your UI slider can be referenced here:

Code (CSharp):

1. public class HealthBar : MonoBehaviour
2. {
3.   public Slider slider; // drag your ui slider to this variable on the player inspector
4.  
5.   // ...
6. }

alternatively, you can do this also if you want to maintain HealthBar on the UI object

there's many ways; choose the best one that fits your goal, but you have to provide reference to your scripts either inspector or using GetComponent<>()

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5. using UnityEngine.UI;
6.  
7. public class Collectible : MonoBehaviour
8. {
9.  
10.    public HealthBar hb;
11.  
12.    void Start ( ) {
13.           // if the UI name is Slider, otherwise provide the "name"
14.           hb = GameObject.Find("Slider").GetComponent<HealthBar>();
15.    }
16.  
17.    private void OnTriggerEnter2D(Collider2D other)
18.     {
19.     if (other.tag == "Player") {
20.           // call your script functions from class HealthBar
21.           hb.AddHealth( )
22.     }
23.   }
24. }

 

You are amazing!!!! The first solution was exactly what I was looking for. Thank you so much for your patience & your help.