unity-test.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GameControl : MonoBehaviour {

	public GameObject[] objects;
	public Transform transform;

	private int current;
	private Vector3 initPos;

	void Awake()
	{
		if (instance == null) {
			instance = this;
		} else {
			DestroyImmediate (this);
		}
	}

	private static GameControl instance;
	public static GameControl Instance
	{
		get
		{ 
			if (instance == null) {
				instance = new GameControl ();
			}

			return instance;
		}
	}

	GameControl() 
	{
		current = 0;
	}

	/**
	 * 获取当前展示对象的索引
	 */ 
	private int currentIndex()
	{
		return current;
	}

	/**
	 * 增加当前展示对象的索引
	 */ 
	private int nextIndex()
	{
		return ++current;
	}

	/**
	 * 切换到下一个对象
	 */ 
	public GameObject nextObject()
	{
		if (currentIndex() > maxIndex()) {
			return null;
		}

		int current = currentIndex ();
		int next = nextIndex ();

		return destroyObject(current).newObject(next);
	}

	/**
	 * 销毁GameObject
	 */ 
	private GameControl destroyObject(int index)
	{
		if (index > maxIndex()) {
			return this;
		}

		Destroy (objects [index]);

		return this;
	}

	/**
	 * 创建一个新的GameObject
	 */
	private GameObject newObject(int index)
	{
		if (index > maxIndex()) {
			return null;
		}

		if (transform != null) {
			initPos = transform.localPosition;

		}

		GameObject obj = Instantiate (objects [index], initPos, Quaternion.identity) as GameObject;

		if (!obj.activeSelf) {
			obj.SetActive (true);
		}

		objects [index] = obj;

		return obj;
	}

	/**
	 * Max index
	 */ 
	private int maxIndex()
	{
		return objects.Length - 1;
	}

	// Update is called once per frame
	void Update () {
		if (Input.GetKeyUp (KeyCode.Space)) {
			nextObject ();
		}
	}
}