有父子关系时的WebAPI与EF code首先生成错误 [英] WebApi with EF Code First generates error when having parent child relation

问题描述

我打破我的头在这个问题上。我没有找到关于它在互联网上的东西，但没有一个明确的答案。我的问题：

I am breaking my head over this issue. I did find something on the internet about it, but not a clear answer. My problem:

我要在MVC3 Web应用程序的模型部分类：
父类和ChildClass
在父类有一个List类型的属性Children

I have to classes in Model section of an MVC3 web app: ParentClass and ChildClass On ParentClass there is a property Children of type List

我用EF code首先，在数据库，整齐地生成一个父表和一个子表给我。

I used EF Code First, which neatly generates a parent table and a child table for me in the database.

现在我需要休息的服务，还给一个列表或一个单一的父类。

Now I need a REST service that gives back a List or a single ParentClass.

当我从父类中删除属性Children是没有问题的。但随着propoerty儿童有我不断收到一个错误。

When I remove the property Children from the ParentClass there is no problem. But with the propoerty Children there I keep getting an error.

错误：的类型System.Data.Entity.DynamicProxies.ParentClass_A0EBE0D1022D01EB84B81873D49DEECC60879FC4152BB115215C3EC16FB8003A是没有预料到，使用XmlInclude或SoapInclude属性来指定不是静态已知类型。}

有些code：

类：

     public class ParentClass
{
    public int ID { get; set; }
    public string Name {get;set;}
    public virtual List<ChildrenClass> Children { get; set; }

}

public class ChildrenClass
{
    public int ID { get; set; }
    public string MyProperty { get; set; }
}

服务：

[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
[ServiceBehavior(IncludeExceptionDetailInFaults = true)] 
public class MyService
{

    static MyContext db;
    public MyService() { db = new MyContext(); }


    [WebGet(UriTemplate = "")]
    public List<ParentClass> GetParents()
    {
        var result = db.Parents.ToList();
        return result;

    }

我不会callinh此服务时，得到的结果。我在做什么错了？

I will not get the result when callinh this service. What am I doing wrong?

推荐答案

我不得不DisableProxyCreation在上下文配置：

I had to DisableProxyCreation in the context configuration:

[OperationContract] 
[WebGet(UriTemplate = "")] 
public List<ParentClass> GetParents() 
{ 
     using (DBContext context = new DBContext()) 
     {
         context.Configuration.ProxyCreationEnabled = false; 
         List<ParentClass> parents = context.Parents
             .Include("Children") 
             .ToList();
         return playlists; 
      }
}

这工作得很好了我。

这篇关于有父子关系时的WebAPI与EF code首先生成错误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！