UWP C#项目中Newtonsoft.Json引发StackOverflowException求助

问题说明 #

将项目JSON序列化方式从System.Text.Json替换为Newtonsoft.Json后，应用可正常运行，但调试会话会被StackOverflowException中断（VS捕获异常，应用未崩溃）。

• 应用启动后调用.Save()方法无异常，仅在上传图片后点击触发ContinueBtn_Click的按钮时出现问题
• 已反复排查代码，未发现明显无限循环逻辑，通过断点和日志确认.Save()与ContinueBtn_Click方法本身仅执行一次

相关代码 #

UserData类（含Save方法） #

public class UserData
{
    public List<CMSession> userSessions { get; set;}
    public DatabaseConnection lastDatabaseConnection { get; set;}
    
    [JsonIgnore]
    JsonSerializerSettings serializerDefaults = new JsonSerializerSettings
    {
        Formatting = Formatting.Indented,
        //PreserveReferencesHandling = PreserveReferencesHandling.All,
        //ReferenceLoopHandling = ReferenceLoopHandling.Serialize,
    };

    public UserData() { userSessions = new List<CMSession>(); }

    /// <summary>
    /// Saves the UserData to a serialized user.json file.
    /// </summary>
    /// <param name="devBreak">If debugging, may provide optional True value to break the debugger prior to save, allowing data manipulation.</param>
    public async Task Save(bool devBreak = false)
    {
        if (devBreak)
        {
            Debug.WriteLine("Saving with Break Mode. You may manipulate UserData in Immediate Window now, otherwise Continue.");
            Debug.Write("");
        }
        try
        {
            StorageFile udFile = await ApplicationData.Current.LocalFolder.GetFileAsync(@"UserData\user.json");
            var udData = JsonConvert.SerializeObject(this, serializerDefaults);
            await Windows.Storage.FileIO.WriteTextAsync(udFile, udData);
            Debug.WriteLine("User data was manually saved.");
        } catch(Exception ex)
        {
            if (App.cmDebugger.debug)
            {
                Debug.WriteLine("Failed to serialize user data to file: " + ex.Message);
            }
        }
    }
}

调用.Save()的ContinueBtn_Click方法 #

// Clicked after user drops some files into a box, the files are processed then added to pendingInit (a List<WorkingImage>)
private async void IUInit_ContinueBtn_Click(object sender, RoutedEventArgs e)
{
    if (pendingInit.Count > 0)
    {
         for (int i = 0; i < pendingInit.Count; i++)
        {
            try
            {
                App.cmSession.IUSession.workAreaImages.Add(pendingInit[i]);
            }
            catch (Exception ex)
            {
                if (App.cmDebugger.debug)
                {
                    Debug.WriteLine("Failed to move pending file to work area: " + ex.Message);
                    try { Debug.WriteLine("Image: " + pendingInit[i].fileName); } catch { }
                }
            }
        }
        IUState = DataState.RefreshNeeded;
        App.cmSession.IUSession.sessionActive = true;
        // This appears to be where the exception occurs. 
        await App.cmData.Save();
        await InitializeIU();
    }
    else
    {
        Init_Grid.Visibility = Visibility.Collapsed;
    }

    IUState = DataState.RefreshNeeded;
}

应用启动后正常生成的JSON示例 #

{
  "userSessions": [
    {
      "LinkedSite": {
        "hasContentAccess": true,
        "hasMediaAccess": true,
        "lastResponse": " (some JSON in here)",
        "friendlyName": "website",
        "URL": "http://www.google.com/",
        "username": "usr",
        "status": "connected",
        "statusDetail": "Connected to the site without errors.",
        "lastConnectionTime": "2023-05-10T15:49:24.0182548-05:00"
      },
      "IUSession": {
        "sessionActive": false,
        "workAreaImages": []
      }
    }
  ],
  "lastDatabaseConnection": null
}

序列化涉及的关联数据结构 #

CMSession

public class CMSession
{
    public SiteConnection LinkedSite { get; set; }
    public ImageUploaderData IUSession {  get; set; }

    public CMSession(SiteConnection linkedSite)
    {
        LinkedSite = new SiteConnection(linkedSite);
        IUSession = new ImageUploaderData();
    }
}

DatabaseConnection

public class DatabaseConnection
{
    public string dbName = database; 
    public string dbstate;
    public MySqlConnection connection;    
}

SiteConnection

public class SiteConnection
{
    public string friendlyName { get; set; }
    public string URL { get; set; }
    public string username { get; set; }
    public string status { get; set; }
    public string statusDetail { get; set; }
    public DateTime lastConnectionTime { get; set; }
    public bool hasContentAccess;
    public bool hasMediaAccess;
    public object lastResponse;
}

ImageUploaderData

public class ImageUploaderData
{
    public bool sessionActive {  get; set; } = false;
    public List<WorkingImage> workAreaImages {  get; set; } 
       = new List<WorkingImage>();
}

内容的提问来源于stack exchange，提问作者Mark L