Collider.OnTriggerEnter(Collider)

# [Collider](https://docs.unity3d.com/cn/2019.4/ScriptReference/Collider.html).OnTriggerEnter(Collider)

## 参数

| other | 该碰撞中涉及的其他 Collider。 |
| ------- | ------------------------------- |

## 描述

[GameObject](https://docs.unity3d.com/cn/2019.4/ScriptReference/GameObject.html) 与另一个 [GameObject](https://docs.unity3d.com/cn/2019.4/ScriptReference/GameObject.html) 碰撞时，Unity 会调用 [OnTriggerEnter](https://docs.unity3d.com/cn/2019.4/ScriptReference/Collider.OnTriggerEnter.html)。

当两个 GameObjects 碰撞时，OnTriggerEnter 会在 FixedUpdate 函数上发生。涉及的碰撞体并不始终在初始接触点处。

**注意：** 两个 GameObjects 都必须包含 Collider 组件。其中一个必须启用 Collider.isTrigger，并包含 Rigidbody。如果两个 GameObjects 都启用了 Collider.isTrigger，则不会发生碰撞。如果两个 GameObjects 都没有 Rigidbody 组件，情况同样如此。

要使用下面的代码示例，请创建原始 [GameObject](https://docs.unity3d.com/cn/2019.4/ScriptReference/GameObject.html)，并向它附加 [Collider](https://docs.unity3d.com/cn/2019.4/ScriptReference/Collider.html) 和 [Rigidbody](https://docs.unity3d.com/cn/2019.4/ScriptReference/Rigidbody.html) 组件。启用 Collider.isTrigger 和 Rigidbody.isKinematic。原始游戏对象碰撞时，将调用 OnTriggerEnter。在本例中，方向立即反转。当 GameObject 退出碰撞时，Unity 调用 OnTriggerExit，更改颜色。

```
using UnityEngine;

public class exampleScript : MonoBehaviour
{
    private float speed = 2f;
    Renderer rend;
    int colorPicker = 0;

private void Start()
    {
        rend = GetComponent<Renderer>();
        transform.position = Vector3.zero;
        transform.rotation = Quaternion.Euler(0, 90, 0);

//Create two GameObjects to act as walls
        GameObject leftWall = GameObject.CreatePrimitive(PrimitiveType.Cube);
        GameObject rightWall = GameObject.CreatePrimitive(PrimitiveType.Cube);
        //Move the walls to the correct positions
        leftWall.transform.position = new Vector3(-10, 0, 0);
        rightWall.transform.position = new Vector3(10, 0, 0);
        //Scale the walls
        leftWall.transform.localScale = new Vector3(1, 2, 1);
        rightWall.transform.localScale = new Vector3(1, 2, 1);
    }

//moves the Primitive 2 units a second in the forward direction
    void Update()
    {
        transform.Translate(Vector3.forward * Time.deltaTime * speed);
    }

//When the Primitive collides with the walls, it will reverse direction
    private void OnTriggerEnter(Collider other)
    {
        speed = speed * -1;
        colorPicker = Random.Range(0, 10);
    }

//When the Primitive exits the collision, it will change Color
    private void OnTriggerExit(Collider other)
    {
        switch (colorPicker)
        {
            case 0: rend.material.color = Color.white; break;
            case 1: rend.material.color = Color.cyan; break;
            case 2: rend.material.color = Color.blue; break;
            case 3: rend.material.color = Color.black; break;
            case 4: rend.material.color = Color.red; break;
            case 5: rend.material.color = Color.green; break;
            case 6: rend.material.color = Color.grey; break;
            case 7: rend.material.color = Color.magenta; break;
            case 8: rend.material.color = Color.yellow; break;
            case 9: rend.material.color = Color.gray; break;
        }
    }
}
```