NullReferenceException: Object reference not set to an instance of an object

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I get the folliwng error- “NullReferenceException: Object reference not set to an instance of an object”,
and it refers me to the following line in my code-
" if (!Touchscreen.current.primaryTouch.press.isPressed) ".

Update-
If I erase those line, the error occures again, and it refers me to the next line that includes “Touchscreen”.

The game works fine.
Any advice?

Thanks!
Aviv

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2

Paste in your complete script and we’ll take a look.

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

public class BallHandler : MonoBehaviour
{
    [SerializeField] private GameObject ballPrefab;
    [SerializeField] private Rigidbody2D pivot;
    [SerializeField] private float detachDelay;
    [SerializeField] private float respawenDelay;

    private Camera mainCamera;
    private Rigidbody2D currentBallRB;
    private SpringJoint2D currentBallSpringJoint;
    private bool isDragging;

    void Start()
    {
        mainCamera=Camera.main;
        SpawnNewBall();
    }

   void Update()
    {
        if (currentBallRB==null) {return;} 
        if (!Touchscreen.current.primaryTouch.press.isPressed)
        {
            if (isDragging)
            {
                LaunchBall();
            }
            isDragging=false;
            return;
        } 
        Vector2 touchPosition=Touchscreen.current.primaryTouch.position.ReadValue();
        Vector3 wordposition = mainCamera.ScreenToWorldPoint(touchPosition);
        currentBallRB.position= wordposition;
        isDragging=true;
        currentBallRB.isKinematic=true; 
    }

    private void LaunchBall()
    {
        currentBallRB.isKinematic=false; 
        currentBallRB=null; 
        Invoke(nameof(DetachBall),detachDelay);                 
    }

    private void DetachBall()
    {
        currentBallSpringJoint.enabled= false;
        currentBallSpringJoint= null;
        Invoke(nameof(SpawnNewBall),respawenDelay);
    }

    private void SpawnNewBall()
    {
        GameObject ballInstance = Instantiate(ballPrefab, pivot.position, Quaternion.identity);
        currentBallRB=ballInstance.GetComponent<Rigidbody2D>();
        currentBallSpringJoint= ballInstance.GetComponent<SpringJoint2D>();
        currentBallSpringJoint.connectedBody=pivot;
    }
}
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4

The code looks correct. Have you enabled Simulate Touch Input From Mouse or Pen in the Input Debugger? (Window/Analysis/InputDebugger) TouchScreen will be null if this is not done.

image
image414×565 23.3 KB

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5

Yes, it’s enabled.
Is there any other place in which I can see if the thouchscreen is null?

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Solved! (but not satisfied)
The error occurs only when I am in game mode. I does not occur when I’m in the simulator.

Thank you Brian!
Aviv

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7

Lol, that happens to me all the time, I get frustrated when the game doesn’t work in the game view, and then finally realize that I need to be in the simulator :rofl:.

Just remember when doing these types of touch inputs like in the course, you can’t use the game view to test, only the simulator

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The simulation of the touch screen, enabling TouchScreen is specifically in the Simulator, not the Game window. It simply doesn’t exist in the Game window. That’s a Unity issue.