ASP.NET MVC 5 在序列化“Data.Item”类型的对象时检测到循环引用

Posted 2023-03-27

【中文标题】ASP.NET MVC 5 在序列化“Data.Item”类型的对象时检测到循环引用

【英文标题】：ASP.NET MVC 5 A circular reference was detected while serializing an object of type 'Data.Item'

【发布时间】：2020-04-27 14:20:54

【问题描述】：

我的 ASP.NET MVC 项目中出现循环引用错误

这是模型

public partial class Item


    public Item()
    
        this.Inventories = new HashSet<Inventory>();
        this.PurchasesDetails = new HashSet<PurchasesDetail>();
        this.SalesDetails = new HashSet<SalesDetail>();
    

    public int Id  get; set; 
    public string Code  get; set; 
    public int CategoryID  get; set; 
    public string Name  get; set; 
    public int MeasurementID  get; set; 
    public int Quantity  get; set; 
    public decimal BuyPrice  get; set; 
    public decimal SalePrice  get; set; 
    public decimal CommisionRate  get; set; 
    public Nullable<System.DateTime> MftDate  get; set; 
    public Nullable<System.DateTime> ExpDate  get; set; 
    public Nullable<int> StockLimit  get; set; 
    public string Description  get; set; 
    public string UserID  get; set; 
    public virtual AspNetUser AspNetUser  get; set; 
    public virtual Category Category  get; set; 
    public virtual ICollection<Inventory> Inventories  get; set; 
    public virtual Measurement Measurement  get; set; 
    public virtual ICollection<PurchasesDetail> PurchasesDetails  get; set; 
    public virtual ICollection<SalesDetail> SalesDetails  get; set; 

这是获取 JSON 的代码

 db.Configuration.ProxyCreationEnabled = false;
        var items = db.Items.Include(i => i.AspNetUser).Include(i => i.Category).Include(i => i.Measurement).ToList();
        return Json(new  data = items , JsonRequestBehavior.AllowGet);

我尝试使用db.Configuration.ProxyCreationEnabled = false;，但它不起作用。任何帮助将不胜感激。

【参考方案1】：

我遇到了同样的问题，我试过了

var plan_master = from s in db.Plan_Master select s;

        var plans = plan_master.Select(S => new
        
            S.Plan_ID,
            S.Plan
        );

        return Json(new  data = plans , JsonRequestBehavior.AllowGet);

【参考方案2】：

在 global.asax 中将这段代码用于全局 Json 序列化设置：

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;

尝试使用以下代码更改以下部分：

string json = JsonConvert.SerializeObject(items, Formatting.None);
    return Json(new  data = json , JsonRequestBehavior.AllowGet);

【讨论】：

我收到此错误 '''Newtonsoft.Json.JsonSerializationException: '自引用循环检测到类型为 'Data.Item'。路径“[0].AspNetUser.Items”。 ''' imgur.com/c9nWVq4