Health/Assets/Scripts/UI/UIManager.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Linq;
using OpenCVForUnity.CoreModule;
using UnityEngine.SceneManagement;
using Yoga;

public class UIManager : MonoSingleton<UIManager>
{
    private Dictionary<Type, UIBase> _panelDic = new Dictionary<Type, UIBase>();
    private Stack<UIBase> _panelStack = new Stack<UIBase>();

    public Camera UiCamera { get; set; }

    private RectTransform _uiPanelRoot;
    private RectTransform _uiPopRoot;
    private RectTransform _hudRoot;

    private Transform _uiRootTrans;

    public override void Init()
    {
        //查找当前scene的摄像机
        UiCamera = Camera.main;

        var canvases = GameObject.FindGameObjectsWithTag("UI");
        GameObject canvas;
        if (canvases.Length <= 0)
        {
            canvas = new GameObject("UICanvas");
            canvas.AddComponent<Canvas>();
        }
        else
            canvas = canvases.ToList().Find(canvas => canvas.name == "UICanvas");

        if (canvas == null)
        {
            canvas = new GameObject("UICanvas");
            canvas.AddComponent<Canvas>();
        }

        _uiRootTrans = canvas.transform;

        //优先层级 最高 hud 最低 panel        
        //panel 挂载节点
        if (transform.Find("PanelRoot") == null)
        {
            _uiPanelRoot = new GameObject("PanelRoot").AddComponent<RectTransform>();
            _uiPanelRoot.SetParent(_uiRootTrans);
            _uiPanelRoot.anchoredPosition = Vector2.zero;
            _uiPanelRoot.anchorMin = Vector2.zero;
            _uiPanelRoot.anchorMax = Vector2.one;
            _uiPanelRoot.offsetMin = Vector2.zero;
            _uiPanelRoot.offsetMax = Vector2.zero;
        }
        else
            _uiPanelRoot = transform.Find("PanelRoot").GetComponent<RectTransform>();

        _uiPanelRoot.SetSiblingIndex(1);

        //pop 挂载节点
        if (transform.Find("PopRoot") == null)
        {
            _uiPopRoot = new GameObject("PopRoot").AddComponent<RectTransform>();
            _uiPopRoot.SetParent(_uiRootTrans);
            _uiPopRoot.anchoredPosition = Vector2.zero;
            _uiPopRoot.anchorMin = Vector2.zero;
            _uiPopRoot.anchorMax = Vector2.one;
            _uiPopRoot.offsetMin = Vector2.zero;
            _uiPopRoot.offsetMax = Vector2.zero;
        }
        else
            _uiPopRoot = transform.Find("PopRoot").GetComponent<RectTransform>();

        _uiPopRoot.SetSiblingIndex(2);

        //hud 挂载节点
        if (transform.Find("HUDRoot") == null)
        {
            _hudRoot = new GameObject("HUDRoot").AddComponent<RectTransform>();
            _hudRoot.SetParent(_uiRootTrans);
            _hudRoot.anchoredPosition = Vector2.zero;
            _hudRoot.anchorMin = Vector2.zero;
            _hudRoot.anchorMax = Vector2.one;
            _hudRoot.offsetMin = Vector2.zero;
            _hudRoot.offsetMax = Vector2.zero;
        }
        else
            _hudRoot = transform.Find("HUDRoot").GetComponent<RectTransform>();
        _hudRoot.SetSiblingIndex(3);
    }

    private T GetPanel<T>() where T : UIBase
    {
        Type type = typeof(T);
        //无缓存，加载相对应的Panel文件
        if (_panelDic.TryGetValue(type, out var panel))
        {
            if (panel != null)
                _panelDic[type].Destroy();
            _panelDic.Remove(type);
        }

        string path = UILoadConfig.GetPath(type.FullName);
        GameObject panelGo = Instantiate(Resources.Load<GameObject>(path));
        panel = panelGo.GetComponent<T>();
        if (panel is UIPanelBase)
            panelGo.transform.SetParent(_uiPanelRoot);
        else if (panel is UIPopupBase)
            panelGo.transform.SetParent(_uiPopRoot);
        else if (panel is UIHudBase)
            panelGo.transform.SetParent(_hudRoot);
        else
            throw new Exception("UIManager.GetPanel() : panel is not a type of UIPanelBase, UIPopupBase or UIHudBase");

        panelGo.transform.localPosition = Vector3.zero;

        _panelDic.Add(type, panel);
        return panel as T;
    }

    public void ShowPanel<T>(params object[] args) where T : UIBase
    {
        T panel = GetPanel<T>();
        panel.Init(args);
        panel.gameObject.SetActive(true);
        panel.OnEnter();
        _panelStack.Push(panel);
    }

    public void ShowPanel<T>(bool hideCurrentPage, params object[] args) where T : UIBase
    {
        if (hideCurrentPage)
        {
            if (_panelStack.Count > 0)
            {
                var topPanel = _panelStack.Peek();
                topPanel.OnPause();
            }
        }

        ShowPanel<T>(args);
    }

    public void ClearPanel()
    {
        foreach (var panel in _panelDic.Values)
        {
            panel.OnExit();
        }
        _panelStack.Clear();
    }

    public void PushPanel<T>() where T : UIBase
    {
        if (_panelStack.Count > 0)
        {
            var topPanel = _panelStack.Peek();
            topPanel.OnPause();
        }

        var panel = GetPanel<T>();
        _panelStack.Push(panel);
        panel.OnEnter();
    }

    private void PopPanel()
    {
        if (_panelStack.Count <= 0)
        {
            return;
        }

        UIBase topPanel = _panelStack.Pop();
        topPanel.OnHide();
        topPanel.OnExit();

        if (_panelStack.Count > 0)
        {
            UIBase nextPanel = _panelStack.Peek();
            nextPanel.OnResume();
        }
    }

    public void CloseCurrent()
    {
        PopPanel();
    }

    public void LoadScene()
    {
        EnableScreenMask();
        var op = SceneManager.LoadSceneAsync("YogaMain");
        op.completed += (operation) =>
        {
            DisableScreenMask();
        };
    }

    public void EnableScreenMask()
    {

    }

    public void DisableScreenMask()
    {

    }

    public void CloseUI(UIBase targetUI)
    {
        if (_panelStack.Count <= 0)
        {
            return;
        }

        targetUI.OnHide();
        targetUI.OnExit();
        //从栈中移除
        _panelStack = new Stack<UIBase>(_panelStack.Where(ui => ui != targetUI));
        //打开顶层页面
        if (_panelStack.Count > 0)
        {
            UIBase nextPanel = _panelStack.Peek();
            nextPanel.OnResume();
        }
    }
}