Unity中UI框架的使用1-添加面板、显示Loading页面

其中BasePanel和Canvas都是挂在面板的预制物上的。

1.导入我们的UI框架（本篇文章中有用的是两个UIPanelType，NUIManager和NBasePanel，会放在文章最后供大家使用）

2.先将我们做好的Panel设置成预制物，注意这边创建一个叫做Resources的文件夹，并且下面创建一个Panel文件夹，然后把预制物都放在里面。

3.在PanelType的脚本文件中注册我们需要管理的面板的信息。（这边注册两个来示范）

4.在PanelType的json配置文件中注册这些面板的名字以及路径信息

5.在Unity中创建一个空物体取名为GameManager并且在其身上挂上一个名叫GameManager的脚本，在脚本的Start方法里写一个弹出面板的功能。

 6.在你的预制物身上挂上Canvas Group和NBasePanel脚本

7.点击运行，可以看到我们在GameManager的Start方法里面写的显示LoadingPanel的语句成功调用，并且在Unity里面成果显出除了此面板的UI。

最后是UI框架的代码

UIPanelType.json：

{
	"PanelList": [
        {
            "PanelName": "LodingPanel",
            "PanelPath": "Panel/LodingPanel"
        },
        {
            "PanelName": "MainPanel",
            "PanelPath": "Panel/MainPanel"
        },
        {
			"PanelName": "PopUp",
			"PanelPath": "Panel/PopUp"
		}

	            ]   
}

DicTool.cs:

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

public static class DicTool{
    public static TValue TryGetValueByNN(this Dictionary dic, TKey type )
    {
        TValue v;

        dic.TryGetValue(type, out v);

        return v;
    }
}

NBasePanel.cs:

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

public class NBasePanel : MonoBehaviour {
    protected CanvasGroup canvas;



    public virtual  void OnEnter()
    {
        if (canvas == null)
        {
            canvas = GetComponent();
        }
      
        print("open");
        canvas.alpha = 1;
        canvas.blocksRaycasts = true;
    }

    public virtual void OnExit()
    {
        print("close");
        canvas.alpha = 0;
        canvas.blocksRaycasts = false;
    }

    public virtual void OnPause()
    {
        print("OnPause");
    }
    public virtual void OnResume()
    {
        print("OnResume");
    }
}

NUIManager.cs:

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

public class NUIManager
{
    private static NUIManager Instance;
    private Transform CanvasTransform;
    UIPanelTypeJson json;

    //打开的顺序  堆 
    Stack PanelStack = new Stack();
    private Dictionary PanelCach = new Dictionary();



    public static NUIManager GetInstance()
    {
        //惰性实例化
        if (Instance == null)
        {
            Instance = new NUIManager();
        }
        return Instance;
    }
    /// 

    /// 现实一个面板
    /// 
    /// 
    public void PushPanel(UIPanelType panelType)
    {
        //调用被挡住的OnPause
        if (PanelStack.Count != 0)
        {
            PanelStack.Peek().OnPause();

        }

        NBasePanel panel = GetPanel(panelType);
        PanelStack.Push(panel);

        panel.OnEnter();


    }

    public void PopPanel()
    {
        if (PanelStack.Count == 0)
            return;
        NBasePanel panel = PanelStack.Pop();
        panel.OnExit();

        if (PanelStack.Count != 0)
            PanelStack.Peek().OnResume();
    }




    private NUIManager()
    {
        ParseUIPanelTypeJson();
        CanvasTransform = GameObject.Find("Canvas").transform;
    }


    private void ParseUIPanelTypeJson()
    {
        //加载json文件
        TextAsset t = Resources.Load("UIPanelType");
        json = JsonUtility.FromJson(t.text);
        Debug.LogError(json.PanelList.Length);
        Debug.LogError(json.PanelList[0].PanelPath);
    }
    /// 

    /// 创建一个面板并且显示
    /// 
    /// 
    /// 
    private NBasePanel GetPanel(UIPanelType panelType)
    {
        GameObject instPanel = PanelCach.TryGetValueByNN(panelType);
        //判断缓存里面有没有，如果没有，创建新的，如果有拿缓存里的
        if (instPanel == null)
        {

            //通过名字找路径
            string path = "";
            foreach (var item in json.PanelList)
            {
                Debug.Log("开始查找" + item.PanelName + ":" + item.PanelPath);
                if (item.PanelName == panelType.ToString())
                {
                    path = item.PanelPath;
                    Debug.Log("找到啦" + item.PanelName);
                }
            }
            Debug.Log("新创建创建啦:" + path);
            instPanel = GameObject.Instantiate(Resources.Load(path)) as GameObject;
            instPanel.transform.SetParent(CanvasTransform, false);
            PanelCach.Add(panelType, instPanel);
        }
        else
        {
            Debug.Log("用的缓存");
        }

        return instPanel.GetComponent();
    }
}

//序列化
[Serializable]
public class UIPanelTypeJson
{
    public UIPanelInfo[] PanelList;
}
//序列化
[Serializable]
public class UIPanelInfo
{
    public string PanelName;
    public string PanelPath;

}

UIPanelType.cs:

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

public enum UIPanelType {
    LodingPanel,
    MainPanel
}