Unity 用简单工厂模式创建对象

首先是要求：

实现点击效果。

用 Plane 或其他物体做地面， tag 为“Finish”

点击地面后，出现一个圆形攻击标记，两秒后自动消失。注意：该攻击标记不能挡住点击。（Primitive Objects / Cylinder）

请使用一个简单工厂创建、管理这些的标记，并自动收回这些标记（注意，这些对象创建后，放在列表内，不必释放）。

写代码的难点在于：

简单工厂其实是不难的，参考之前的代码可以很快写出

一个注意的地方在于射线的不遮挡

还有一个是延时调用的处理

全部代码如下:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using Com.mygame;

namespace Com.mygame{
public class myFactory : System.Object{
public List<GameObject> objs = new List<GameObject>();
private static myFactory _instance;
private Camera cm;
public Vector3 uselessposition =  new Vector3(0f,-2f,0f);

public static myFactory GetInstance(){
if (_instance == null) {
_instance = new myFactory ();
}
return _instance;
}

public void placeAttackmark(Vector3 target){
cm = Camera.main;
Ray ray = cm.ScreenPointToRay (target);
RaycastHit hit;
if(Physics.Raycast(ray,out hit)){
if (hit.collider.gameObject.tag.Contains ("Finish")) {
Vector3 finishposition = hit.point + new Vector3(0f,0.5f,0f);
//
if (objs.Count == 0) {
GameObject sp = GameObject.CreatePrimitive (PrimitiveType.Cylinder);
sp.GetComponent<Collider> ().enabled = false;
sp.transform.position = hit.point+ new Vector3(0f,0.5f,0f);;
// 在这里我给每一个新创建的对象添加控制延时的类，继承与monobehavier
waitTime wt = sp.AddComponent<waitTime>();
// 给它添加延时函数，传入List，在延时函数中执行list的添加
wt.delayfunction (sp,objs);
} else {
GameObject sp = objs [0];
objs.RemoveAt (0);
sp.transform.position = hit.point + new Vector3(0f,0.5f,0f);
//add a timeclass
waitTime wt = sp.AddComponent<waitTime>();
wt.delayfunction (sp,objs);

}
}
}
}

//delay time
public class waitTime : MonoBehaviour {
public List<GameObject> objss;
public GameObject obj;

public void delayfunction(GameObject sp,List<GameObject> objs){
StartCoroutine (Waitanddo(sp));
this.objss = objs;
this.obj = sp;
}

public IEnumerator Waitanddo(GameObject sp){
yield return new WaitForSeconds(2.0f);
//
this.transform.position = new Vector3 (0f,-2f,0f);
objss.Add (obj);
}
}
}

}

public class basecode : MonoBehaviour {

private Camera cm;
private GameObject temp;
// Use this for initialization
void Start () {
cm = Camera.main;
}

// Update is called once per frame
void Update () {
if (Input.GetMouseButtonDown (0)) {
Vector3 mp = Input.mousePosition;
myFactory.GetInstance ().placeAttackmark (mp);
}
}
}