Unity存档系统——Json格式的文件

实例场景

 点击Save按钮后，查看保存的文件

点击Load按钮后加载文档数据

Json介绍https://www.json.org/json-zh.htmlUnity中自带的JsonUtility可以将可序列化对象与Json格式相互转换。

将对象转为可序列化对象需要添加[SerializeField]，且为public，然后才可以被转为Json格式。

JsonUtility内部API

JsonUtility.ToJson将object对象转为Json格式

//两种重载
public static string ToJson(object obj);
public static string ToJson(object obj, bool prettyPrint);
 
//obj为被转换为Json格式的对象
//prettyPrint为是否将输出的Json文本转为适合阅读的格式，默认false，尽量不选true，对性能有影响
//返回值为Json格式的string数据

JsonUtility.FromJson将Json格式转为object格式

public static T FromJson<T>(string json);
 
//T为泛型，代各类数据
//json为json格式的数据
//返回值为某格式的对象

 JsonUtility.FromJsonOverwrite通过读取对象的 JSON 表示形式覆盖其数据

public static void FromJsonOverwrite(string json, object objectToOverwrite);
 
//json为对象的json格式
//objectToOverwrite为被重写的对象

这个方法与JsonUtility.FromJson不同在于：不产生新的对象加载Json格式，而是在已有的对象内加载Json格式，无需进行任何分配即可更新存储在类或对象中的值。

输入输出流

命名空间：using System.IO

File.WriteAllText 写入文件

public static void WriteAllText (string path, string ?contents);
 
//path：文件路径
//contents：文件内容

path一般指定为：Application.persistentDataPath，避免平台不同发生错误

该值是目录路径；此目录中可以存储每次运行要保留的数据。在 iOS 和 Android 上发布时，persistentDataPath 指向设备上的公共目录。应用程序更新不会擦除此位置中的文件。用户仍然可以直接擦除这些文件。 

如果文件已经存在，则会将第二次输入的内容覆盖到原文件中，不会创建新文件。 

File.ReadAllText 读取文件

public static string ReadAllText (string path);
 
//path：文件路径
//返回值为json格式的字符串

File.ReadAllText 读取文件

public static void ReadAllText (string path);

try—catch语句 

源码

PlayerSystem

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
 
 
public class PlayerSystem : MonoBehaviour
{
    public List<Text> text = new List<Text>();
 
    [SerializeField] string playerName;
    [SerializeField] string playerMoney;
    [SerializeField] string playerLevel;
    [SerializeField] string playerScore;
 
    const string PLAYER_FILE_NAME = "playerFile";
 
    void  Update() {
        text[0].text = playerName;
        text[1].text = playerMoney;
        text[2].text = playerLevel;
        text[3].text = playerScore;
    }
    public void Save(){
        var player = new Player();
 
        player.playerName = playerName;
        player.playerMoney = playerMoney;
        player.playerLevel = playerLevel;
        player.playerScore = playerScore;
 
        SaveFile.SaveByJson(PLAYER_FILE_NAME,player);
    }
 
    public void Load(){
        Player savePlayer = SaveFile.LoadFromJson<Player>(PLAYER_FILE_NAME);
 
        playerName = savePlayer.playerName;
        playerMoney = savePlayer.playerMoney;
        playerLevel = savePlayer.playerLevel;
        playerScore = savePlayer.playerScore;
    }
 
    [UnityEditor.MenuItem("Developer/Delete Player Prefabs")]
    public static void DeletePlayerSavaFiles(){
        SaveFile.DeleteSaveFile(PLAYER_FILE_NAME);
    }
 
    [SerializeField] class Player{
        public string playerName;
        public string playerMoney;
        public string playerLevel;
        public string playerScore;
    }
}

SaveSystem

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
 
public class SaveFile 
{
    //存储文件
    public static void SaveByJson(string fileName,object data){
        var json = JsonUtility.ToJson(data);
        var path = Path.Combine(Application.persistentDataPath,fileName);
        
 
        try{
            File.WriteAllText(path,json);
            Debug.Log("存储成功");
        }
        catch(System.Exception e){
            Debug.Log("存储失败");
        }
    }
 
    //加载文件
    public static T LoadFromJson<T>(string fileName){
        var path = Path.Combine(Application.persistentDataPath,fileName);
        
 
        try{
            var json = File.ReadAllText(path);
            var data = JsonUtility.FromJson<T>(json);
            
            Debug.Log("读取成功");
            return data;
        }
        catch(System.Exception e){
            
            Debug.Log("读取失败");
            return default;
        }
 
    }
 
    //删除文件
    public static void DeleteSaveFile(string fileName){
        var path = Path.Combine(Application.persistentDataPath,fileName);
 
        try{
            File.Delete(path);
            Debug.Log("删除成功");
        }
        catch(System.Exception e){
            Debug.Log("删除失败");
        }
        
    }
}