Alex教程每一P的教程原代码加上我自己的理解初步理解写的注释，可供学习Alex教程的人参考
此代码仅为较上一P有所改变的代码

【Unity教程】从0编程制作类银河恶魔城游戏_哔哩哔哩_bilibili

 FileDataHandler.cs

using System;
using System.IO;
using UnityEngine;
public class FileDataHandler
{private string dataDirPath = "";private string dataFileName = "";public FileDataHandler(string _dataDirPath, string _dataFilePath)//构造函数拿到需要保存的位置和文件名称{dataDirPath = _dataDirPath;dataFileName = _dataFilePath;}public void Save(GameData _data){string fullPath = Path.Combine(dataDirPath, dataFileName);//合成路径函数 将位置和文件合并成实际的可以读取的路径try//用try防止其报错{Directory.CreateDirectory(Path.GetDirectoryName(fullPath));//通过路径创建出需要的文件，存在就不创建了string dataToStore = JsonUtility.ToJson(_data, true);//将传过来的gameData转换成文本形式并且使其可读using (FileStream stream = new FileStream(fullPath, FileMode.Create))//两个using 第一个进入文件使其变为可编写模式{using (StreamWriter writer = new StreamWriter(stream))//第二个拿到文件对其进行编辑{writer.Write(dataToStore);//写入函数}}}catch (Exception e){Debug.LogError("Error on trying to save data to file " + fullPath + "\n" + e);}}public GameData Load()//同上{string fullPath = Path.Combine(dataDirPath, dataFileName);GameData loadData = null;if (File.Exists(fullPath)){try{string dataToLoad = "";using (FileStream stream = new FileStream(fullPath, FileMode.Open)){using (StreamReader reader = new StreamReader(stream)){dataToLoad = reader.ReadToEnd();}}loadData = JsonUtility.FromJson<GameData>(dataToLoad);//转换为游戏需要的类型}catch (Exception e){Debug.LogError(e);}}return loadData;}
}

ISaveManager.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public interface ISaveManager
{void LoadData(GameData _data);void SaveData(ref GameData _data);
}

SaveManager.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Linq;public class SaveManager : MonoBehaviour
{public static SaveManager instance;[SerializeField] private string fileName;GameData gameData;private List<ISaveManager> saveManagers;private FileDataHandler dataHandler;private void Awake(){if (instance != null)Destroy(instance);elseinstance = this;}private void Start(){dataHandler = new FileDataHandler(Application.persistentDataPath, fileName);saveManagers = FindAllSaveManagers();LoadGame();}public void NewGame(){gameData = new GameData();}public void LoadGame(){gameData = dataHandler.Load();if(this.gameData == null){Debug.Log("No data");NewGame();}foreach(ISaveManager saveManager in saveManagers)//循环调用所有的找到脚本的LoadData和SaveData到，这样便可以将所有的数据汇聚到gameData中，并从中拿到data{saveManager.LoadData(gameData);}Debug.Log("Loaded currency " + gameData.currency);}public void SaveGame()循环调用所有的找到脚本的LoadData和SaveData到，这样便可以将所有的数据汇聚到gameData中，并从中拿到data{foreach(ISaveManager saveManager in saveManagers){saveManager.SaveData(ref gameData);}dataHandler.Save(gameData);}private void OnApplicationQuit(){SaveGame();}private List<ISaveManager> FindAllSaveManagers()//全局寻找带ISave的脚本的函数{IEnumerable<ISaveManager> saveManager = FindObjectsOfType<MonoBehaviour>().OfType<ISaveManager>();return new List<ISaveManager>(saveManager);}
}

GameData.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
[System.Serializable]
public class GameData
{public int currency;public GameData(){this.currency = 0;}
}

PlayerManager.cs

using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;public class PlayerManager : MonoBehaviour, ISaveManager
{public static PlayerManager instance;public Player player;//这是通过在外部设置了一个组件，让这个组件能够直接把Player找到，从而减少FInd的方式所带来的高负载public int currency;private void Awake(){if(instance != null){Destroy(instance.gameObject);}elseinstance = this;}public bool HaveEnoughMoney(int _price){if(_price > currency){Debug.Log("Not enough money");return false;}currency -= _price;return true;}public int GetCurrency() => currency;public void LoadData(GameData _data){currency = _data.currency;}public void SaveData(ref GameData _data){_data.currency = this.currency;}
}