序列化/反序列化特定文件时遭遇Stack Overflow错误，求解决

问题现象 #

程序执行序列化/反序列化时抛出Stack Overflow异常，调用栈显示循环调用构造函数：

at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at csproj.coupMechanics..ctor()
   at csproj.gameManagement..ctor()
   at Program.<Main>$(System.String[])

相关代码片段 #

coupMechanics类 #

public class coupMechanics : coupSettings
{
    public string path = @$"{Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}\nothing\msd-temp-file.xml";
    public string path2 = $@"{Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}\nothing\deletable.txt";

    gameManagement gm = new gameManagement();
    user u = new user();
    player temprorary = null;

    public List<player> players = new List<player>();
    public XmlSerializer xs = new XmlSerializer(typeof(List<player>));
}

gameManagement类片段 #

try
{
    using (fs = new FileStream(c.path, FileMode.Open, FileAccess.Read))
    {
        users = (List<user>)c.xs.Deserialize(fs);
    }
    foreach (var idi in users)
    {
        if (idi.id.CompareTo(id) == 1)
        {
            id = idi.id;
        }
    }
    id++;
}
catch (FileNotFoundException ex) {
    id = 0;
}

问题根源 #

从调用栈的循环模式可以确定：coupMechanics类初始化时直接创建gameManagement实例，而gameManagement的构造函数内部又会创建coupMechanics实例，形成无限递归的循环依赖，导致栈空间耗尽，抛出Stack Overflow异常。

解决步骤 #

1. 打破循环依赖

   • 移除类内部的直接实例化，改用构造函数传递依赖：
     • 修改coupMechanics类，通过构造函数接收gameManagement实例：

       public class coupMechanics : coupSettings
       {
           public string path = @$"{Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}\nothing\msd-temp-file.xml";
           public string path2 = $@"{Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}\nothing\deletable.txt";
       
           public gameManagement gm;
           public user u = new user();
           public player temprorary = null;
       
           public List<player> players = new List<player>();
           public XmlSerializer xs = new XmlSerializer(typeof(List<player>));
       
           public coupMechanics(gameManagement gmInstance)
           {
               gm = gmInstance;
           }
       }
       

     • 修改gameManagement类，构造函数接收coupMechanics实例，避免内部重新创建：

       public class gameManagement
       {
           private coupMechanics _c;
           public List<user> users;
           public int id;
       
           public gameManagement(coupMechanics cInstance)
           {
               _c = cInstance;
               try
               {
                   using (var fs = new FileStream(_c.path, FileMode.Open, FileAccess.Read))
                   {
                       users = (List<user>)_c.xs.Deserialize(fs);
                   }
                   foreach (var idi in users)
                   {
                       if (idi.id.CompareTo(id) == 1)
                       {
                           id = idi.id;
                       }
                   }
                   id++;
               }
               catch (FileNotFoundException ex)
               {
                   id = 0;
               }
           }
       }
       

     • 程序入口处初始化时，先创建其中一个实例，再双向绑定：

       var mechanics = new coupMechanics(null);
       var management = new gameManagement(mechanics);
       mechanics.gm = management;
       

2. 检查序列化对象的循环引用

   • 如果user、player等序列化对象之间存在循环引用，给不需要序列化的引用属性添加[XmlIgnore]特性，避免XmlSerializer处理异常：

     public class player
     {
         public int Id { get; set; }
         [XmlIgnore]
         public user RelatedUser { get; set; }
     }
     

内容的提问来源于stack exchange，提问作者george tavadze