VR开发--搭建UI框架（3）

using UnityEngine;
using System.Collections;
// 单例类：只要继承这个类，那么继承者就是一个单例类


// 限定T是一个class类型，可以new 
public abstract class Singleton<T> where T : class,new()
{
    protected static T _instance = null;
    public static T Instance
    {
        get {
            if (null == _instance)
            {
                _instance = new T();
            }
            return _instance;
        }
    }

    protected Singleton()
    {
        if (null != _instance)
        {
            throw new SingletonException("this" + (typeof(T)).ToString() + "singleton Instance is not null");
            Init();
        }
    }
    public virtual void Init()
    { }
}

using UnityEngine;
using System.Collections;
// 跨场景不销毁的单例

// 继承一个MonoBehaviour，但是T 类型是继承SYSingleton的子类
public abstract class SYSingleton<T>:MonoBehaviour where T : SYSingleton<T>{
    protected static T _instance = null;
    public static T Instance
    {
        get {
            if (null == _instance)
            {
                // 去寻找一个对象
                GameObject go = GameObject.Find("SYGameObject"); 
                if (null == go)
                {
                    go = new GameObject("SYGameObject");
                    DontDestroyOnLoad(go); // 切换场景不销毁
                }
                //  _instance = go.GetOrAdd<T>(); 将协成管理类的方法掉用
                // 另一种方法：
                _instance = go.GetComponent<T>();
                if (_instance == null)
                {
                    _instance = go.AddComponent<T>();
                }
                return _instance;
            }
            return _instance;
        }
    }
    private void OnApplicationQuit()
    {
        _instance = null;
    }
}

 // 实际打开面板的代码都在这里面
    private void OpenPanal(bool isCloseOther, Type[] uitypes, params object[] args)
    {
        if (isCloseOther)
        {
            CloseOtherPanal();
        }
        int length = uitypes.Length;
        for (int i = 0; i < length; i++)
        {
            Type _uitype = uitypes[i];
            GameObject panal;
            if (OpenPanaldic.TryGetValue(_uitype, out panal) && panal != null)
            {
                // 显示面板
            }
            else
            {  // 将面板数据模型Push进去
                stackModels.Push(new UIModel(_uitype, "", args));
            }
            // 如果栈的长度 > 0；
            if (stackModels.Count > 0)
            {
                CoroutineController.Instance.StartCoroutine("");
            }
        } 
    }