ModelProject/Assets/Scripts/UINavigation.cs

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

public class UINavigation
{
    private static int count;
    public static List<UiBase> History;
    public static List<UiBase> PopHistory;

    public static void Init()
    {
        if(History != null || PopHistory != null)
        {
            return;
        }
        History = new List<UiBase>();
        PopHistory = new List<UiBase>();
    }

    public static void Clear()
    {
        History.Clear();
        PopHistory.Clear();
    }

    public static void AddItem(UiBase view)
    {
        if (view == null)
            return;
        if (view.needNavigation)        
        {
            //弹出窗体后面的窗体冻结
            UiBase lastView = GetLastItem();
            if (lastView != null)
                lastView.Freeze();

            History.Add(view);
        }

        if (view.needPopNavigation)
        {
            UiBase lastView = GetPopLastItem();
            if (lastView != null)
                lastView.Freeze();

            PopHistory.Add(view);
        }
    }

    public static void RemoveLastItem(UiBase view)
    {
        if (view == null)
            return;

        if (view.needNavigation)
        {
            //从栈中移除
            UiBase lastView = GetLastItem();
            if(lastView == view)
            {
                count = History.Count;
                if (count == 0)
                    return;
                History.RemoveAt(count - 1);
            }
        }
        if (view.needPopNavigation)
        {
            UiBase lastView = GetPopLastItem();
            if (lastView == view)
            {
                count = PopHistory.Count;
                if (count == 0)
                    return;
                PopHistory.RemoveAt(count - 1);
            }
        }
    }

    public static UiBase GetLastItem()
    {
        count = History.Count;
        if (count == 0)
            return null;
        UiBase data = History[count - 1];
        return data;
    }

    /// <summary>
    /// 找到上一个打开过后已关闭的界面
    /// </summary>
    /// <returns></returns>
    public static UiBase GetLastOpenView()
    {
        count = History.Count;
        if (count <=1)
            return null;
        UiBase data = History[count - 2];
        return data;
    }

    public static UiBase GetPopLastItem()
    {
        count = PopHistory.Count;
        if (count == 0)
            return null;
        UiBase data = PopHistory[count - 1];
        return data;
    }
}