问题描述
在 Unity 中,我的玩家游戏对象有 4 个轮子,并且所有轮子都包含轮对撞机。我想获得这些的转速。
我写了这段代码,但在第 33 行,它抛出了索引/参数越界异常,这意味着它试图用 'GetChild(i)' 访问的索引不可访问。 第 33 行是
wColliders[i] = gameObject.transform.GetChild(i).gameObject.GetComponent<WheelCollider>();
我的播放器有 5 个子对象,其中 4 个有轮对撞机。怎么解决?
```
public class PlayerController : MonoBehaviour
{
//[SerializeField] private float speed = 10f;
[SerializeField] private float speed;
[SerializeField] private float rpm;
private float totalRpm;
[SerializeField] private float horsePower;
[SerializeField] private float turnSpeed;
public float horizontalInput;
public float forwardInput;
[SerializeField] private GameObject centerOfMass;
[SerializeField] TextMeshProUGUI speedometerText;
[SerializeField] TextMeshProUGUI rpmText;
List<WheelCollider> wColliders;
private Rigidbody playerRb;
// Start is called before the first frame update
void Start()
{
playerRb = GetComponent<Rigidbody>();
playerRb.centerOfMass = centerOfMass.transform.position;
wColliders = new List<WheelCollider>();
for(int i = 0; i < 4; i++)
{
wColliders[i] = gameObject.transform.GetChild(i).gameObject.GetComponent<WheelCollider>();
}
}
// Update is called once per frame
void FixedUpdate()
{
horizontalInput = Input.GetAxis("Horizontal");
forwardInput = Input.GetAxis("Vertical");
playerRb.AddRelativeForce(Vector3.forward * horsePower * forwardInput);
transform.Rotate(Vector3.up,Time.deltaTime * turnSpeed * horizontalInput);
speed = playerRb.velocity.magnitude;
speed = Mathf.RoundToInt(speed);
speedometerText.SetText("Speed: " + speed);
for(int i = 0; i < wColliders.Count; i++)
{
totalRpm += wColliders[i].rpm;
}
rpm = Mathf.Round(totalRpm / wColliders.Count);
rpmText.SetText("RPM: " + rpm);
}
}
解决方法
你得到 IndexOutOfBoundsException
不是因为 Unity 没有找到孩子,而是因为你试图访问/设置
wColliders[i]
空列表。尚未添加任何项目,因此您无法通过索引访问它们。
您宁愿使用 List<T>.Add
for(var i = 0; i < 4; i++)
{
wColliders.Add(transform.GetChild(i).GetComponent<WheelCollider>());
}
或者实际上只是简单地使用 GetComponentsInChildren
wColliders = GetComponentsInChildren<WheelCollider>(true).ToList();