using UnityEngine;using System.Collections;public class fire : MonoBehaviour{    public float rate = 0.2f;    public GameObject bullet;    private void Start()    {        OnFire();    }    //实例化子弹    public void Fire()    {        GameObject.Instantiate(bullet, transform.position, Quaternion.identity);    }    //如何实例化子弹    public void OnFire()    {        InvokeRepeating("Fire",2,rate);    }}