给物体添加触发器，进行事件的判断检测

Collider.OnTriggerEnter(Collider)

Description:

OnTriggerEnter is called when the Collider other enters the trigger.

This message is sent to the trigger collider and the rigidbody (if any) that the trigger collider belongs to, and to the rigidbody (or the collider if there is no rigidbody) that touches the trigger. Notes: Trigger events are only sent if one of the colliders also has a rigidbody attached. Trigger events will be sent to disabled MonoBehaviours, to allow enabling Behaviours in response to collisions.

例子1：

using UnityEngine;
using System.Collections;
public class ExampleClass : MonoBehaviour {
    void OnTriggerEnter(Collider other) {
        Destroy(other.gameObject);
    }
}

例子2：

using UnityEngine;
using System.Collections;
public class ExampleClass : MonoBehaviour {

      public List<GameObject> enemys = new List<GameObject>;
      
      //检测到物体
    void OnTriggerEnter(Collider other)
      {
        if(other.tag == "Enemy")
            {
                enemys.Add(other.gameObject);
            }
    }
      
      //物体离开检测区域  
      void OnTriggerExit(Collider other)
      {
          enemys.Remove(other.gameObject);
      }
}

**使用触发器需要将Collider的isTrigger勾选上**