Index out of bounds error. How do i fix it?

Question

This is error deltaVector = (Vector3)Input.GetTouch(0).position - transform.position; full code here:

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class JoystickController : 
MonoBehaviour, IPointerUpHandler, IPointerDownHandler {

        public ControllerInput tankPlayer;
        public float offset = 35.0f;

        public Sprite button_not_touch;
        public Sprite button_touch;

        public Image[] imageButtons;

        private bool isTouch;
        private Vector3 deltaVector;

  void Update()
  {
    // When touch, process touch postion
    if (isTouch) {

      // Check touch, if have mutiple touch
      Touch[] myTouchs = Input.touches;
      Vector3 touchPos = Vector3.zero;

      if (myTouchs.Length > 1) {
        for (int i = 0; i < myTouchs.Length; i++)
        {
          if (myTouchs[i].position.y < transform.position.y * 2 && myTouchs[i].position.x < transform.position.x * 2) {
            touchPos = myTouchs[i].position;
            break;
          }
        }
        deltaVector = touchPos - transform.position;
      }
      else
        deltaVector = (Vector3)Input.GetTouch(0).position - transform.position;
      Debug.Log("log");
      // Process when magnitude delta vector greater than 25
      if (Vector3.Magnitude(deltaVector) > 25.0f) {
        if (Mathf.Abs(deltaVector.x) > Mathf.Abs(deltaVector.y)) {
          // Move horizontal
          if (deltaVector.x > offset) {
            tankPlayer.MoveRight();
            ButtonHit(3);
          } else if (deltaVector.x < -offset) {
            tankPlayer.MoveLeft();
            ButtonHit(1);
          }
        } else {
          // Move vertical
          if (deltaVector.y > offset) {
            tankPlayer.MoveUp();
            ButtonHit(0);
          } else if (deltaVector.y < -offset) {
            tankPlayer.MoveDown();
            ButtonHit(2);
          }
        }
      } else
      tankPlayer.Release();
    } else
      tankPlayer.Release();
  }

  // Method to change button sprites
  void ButtonHit(int indexTouch)
  {
    foreach(Image image in imageButtons)
    image.sprite = button_not_touch;


    imageButtons[indexTouch].sprite = button_touch;
  }

        // Event handle when touch to joystick
        public void OnPointerUp(PointerEventData eventData )
  {

    foreach(Image image in imageButtons)
    image.sprite = button_not_touch;

    isTouch = false;
  }

        // Event handle when touch to joystick
        public void OnPointerDown(PointerEventData eventData)
  {
    isTouch = true;
  }

  void OnDisable()
  {
    tankPlayer.Release();
  }
}

score 2 · Answer 1 · answered Oct 10 '17 at 10:20

2

You should check that myTouchs has at least one element. Actually, you can enter the else branch even if myTouchs is empty, and this raises the exception.

answered Oct 10 '17 at 10:20

Andrea

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Thank you very much Andrea, you can fix code help me,I have fixed it but don't ;((( – Richey Oct 10 '17 at 15:56

Chopi · Answer 2 · 2017-10-10T10:55:39.080

If myTouchs.Length < 1 this means myTouchs contains 0 elements.

So if you do Input.GetTouch(0) it will return null has there is no Touch avaliable in the GetTouch array

In your else add this condition

else if( myTouchs.Length == 1) 
//your code

or change your initial if to

 if (myTouchs.Length >= 1)

Changing the else should look like

 if (myTouchs.Length > 1) {
    for (int i = 0; i < myTouchs.Length; i++)
    {
      if (myTouchs[i].position.y < transform.position.y * 2 && myTouchs[i].position.x < transform.position.x * 2) {
        touchPos = myTouchs[i].position;
        break;
      }
    }
    deltaVector = touchPos - transform.position;
  }
  else if( myTouchs.Length == 1)

Index out of bounds error. How do i fix it?

2 Answers2

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