public class EnemyMoveAI : MonoBehaviour {

    public Transform[] wayPoints;
    public float patrolTime = 3f;
    private int index = 0;
    private float patrolTimer = 0;
    private NavMeshAgent navAgent;

    void Awake()
    {
        navAgent = GetComponent<NavMeshAgent>();
        navAgent.destination = wayPoints[index].position;
    }
	
	// Update is called once per frame
	void Update () {
        Patrolling();
	}

    private void Patrolling()
    {
        if (navAgent.remainingDistance < 0.5f)
        {
            navAgent.isStopped = true;
            patrolTimer += Time.deltaTime;
            if (patrolTimer > patrolTime)
            {
                index++;
                index %= 4;
                navAgent.destination = wayPoints[index].position;
                patrolTimer = 0;
            }
        }
    }
}

这边目的地也赋值了