在将对象序列化到JSON时，循环引用检测到异常 [英] Circular reference detected exception while serializing object to JSON

问题描述

正如此所述发布时，序列化实体框架代理时，我收到Json序列化错误：

Just as mentioned in this post, I am getting a Json serialization error while serializing an Entity Framework Proxy:

在序列化
'System.Data.Entity.DynamicProxies.PurchaseOrder_446B939192F161CDBC740067F174F7A6059B0F9C0EEE68CD3EBBD63CF9AF5BD0'。

A circular reference was detected while serializing an object of type 'System.Data.Entity.DynamicProxies.PurchaseOrder_446B939192F161CDBC740067F174F7A6059B0F9C0EEE68CD3EBBD63CF9AF5BD0'.

但不同的是，我不要在我的实体中有一个循环引用，在我们的生产环境中只出现 。本地一切工作正常...

But the difference is, I don't have a circular reference in my entities, and it only occurs in our production environment. Locally everything works fine...

我的实体：

public interface IEntity
{
    Guid UniqueId { get; }
    int Id { get; }
} 

public class Entity : IEntity
{
    public int Id { get; set; }
    public Guid UniqueId { get; set; }
}

public class PurchaseOrder : Entity
{
    public string Username { get; set; }
    public string Company { get; set; }

    public string SupplierId { get; set; }
    public string SupplierName { get; set; }

    public virtual ICollection<PurchaseOrderLine> Lines { get; set; }
}

public class PurchaseOrderLine : Entity
{
    public string Code { get; set; }
    public string Name { get; set; }
    public decimal Quantity { get; set; }
}

我的PurchaseOrderController上的GetCurrent操作抛出异常：

The GetCurrent action on my PurchaseOrderController throwing the exception:

public class PurchaseOrderController : Controller
{
    private readonly IUnitOfWork _unitOfWork;

    public PurchaseOrderController(IUnitOfWork unitOfWork)
    {
        _unitOfWork = unitOfWork;
    }

    public JsonResult GetCurrent()
    {
        return Json(EnsurePurchaseOrder(), JsonRequestBehavior.AllowGet);
    }

    private PurchaseOrder EnsurePurchaseOrder()
    {
        var company = RouteData.GetRequiredString("company");
        var repository = _unitOfWork.GetRepository<PurchaseOrder>();

        var purchaseOrder = repository
                .Include(p => p.Lines)
                .FirstOrDefault
                (
                    p => p.Company == company && 
                         p.Username == User.Identity.Name
                );

        if (purchaseOrder == null)
        {
            purchaseOrder = repository.Create();
            purchaseOrder.UniqueId = Guid.NewGuid();
            purchaseOrder.Company = company;
            purchaseOrder.Username = User.Identity.Name;
            _unitOfWork.SaveChanges();
        }

        return purchaseOrder;
    }
}

推荐答案

POCO实体是完美可序列化的。您的问题是EF运行时为您创建的动态代理通常不是。您可以将 context.Configuration.ProxyCreationEnabled 设置为 false ，但是您将失去延迟加载。我强烈的建议是使用支持EF实体序列化的 Json.NET ：

Your POCO entities are perfectly serializable. Your problem is that the dynamic proxies the EF runtime creates for you are usually not. You can set the context.Configuration.ProxyCreationEnabled to false but then you lose lazy loading. My strong recommendation to you is to use Json.NET which supports serialization for EF entities:

ADO.NET实体框架支持意外地添加到Json.NET

.NET的高性能JSON框架

这篇关于在将对象序列化到JSON时，循环引用检测到异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！