unity简单资源管理

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;
using UnityEngine.UI;

//资源管理器
public class SFxResMananger : MonoBehaviour
{
    private static SFxResMananger _instance;
    public static SFxResMananger Instance
    {
        get
        {
            return _instance;
        }
    }

    private Dictionary<string, GameObject> resDictionary = new Dictionary<string, GameObject>();

    private GameObject panelLevel;
    private GameObject windowLevel;
    private GameObject alertLevel;

    public float screenWRate;
    public float screenHRate;

    private void Awake()
    {
        _instance = this;
    }

    // Start is called before the first frame update
    void Start()
    {
        //构建ui结构
        GameObject UI = new GameObject("UI");
        Canvas canvas = UI.AddComponent<Canvas>();
        canvas.renderMode = RenderMode.ScreenSpaceOverlay;
        UI.AddComponent<CanvasScaler>();
        UI.AddComponent<GraphicRaycaster>();

        panelLevel = new GameObject("panelLevel");
        panelLevel.transform.SetParent(UI.transform);
        panelLevel.transform.localPosition = Vector3.zero;

        windowLevel = new GameObject("windowLevel");
        windowLevel.transform.SetParent(UI.transform);
        windowLevel.transform.localPosition = Vector3.zero;

        alertLevel = new GameObject("alertLevel");
        alertLevel.transform.SetParent(UI.transform);
        alertLevel.transform.localPosition = Vector3.zero;

        //计算适配
        float resScreenW = 1920;
        float resScreenH = 1080;
        float curScreenW = Screen.width;
        float curScreenH = Screen.height;

        screenWRate = curScreenW / resScreenW;
        screenHRate = curScreenH / resScreenH;
    }

    public GameObject ShowPanel(string path) {
        return LoadRes(path, panelLevel.transform);
    }

    public GameObject ShowWindow(string path)
    {
        return LoadRes(path, windowLevel.transform);
    }

    public GameObject ShowAlert(string path)
    {
        return LoadRes(path, alertLevel.transform);
    }

    public GameObject ShowItem(string path,Transform parent)
    {
        return LoadRes(path, parent);
    }

    private GameObject LoadRes(string path, Transform parent) {

        if (resDictionary.ContainsKey(path))
        {
            GameObject go = Instantiate(resDictionary[path]);
            go.transform.SetParent(parent);
            go.transform.localScale = new Vector3(screenWRate, screenHRate, 1);
            go.transform.localPosition = Vector3.zero;

            return go;
        }
        else
        {
            GameObject res = Resources.Load(path) as GameObject;
            resDictionary.Add(path, res);
            return LoadRes(path, parent);
        }

    }
}