Question

如何在web api中设置通用集合以进行序列化？我有课程

public partial class User:BaseEntity
{
    [Required,MaxLength(100), MinLength(5)]
    [Index(IsUnique = true)]
    public string Login { get; set; }

    [Required, MaxLength(100), MinLength(64)]
    public byte[] Password { get; set; }

    [MaxLength(100),MinLength(5)]
    [EmailAddress]
    [Index(IsUnique=true)]
    public string Email { get; set; }


    [MaxLength(40), MinLength(4)]
    [Index(IsUnique = true)]
    public string NickName { get; set; }

    [MaxLength(100), MinLength(4)]
    public string FullName { get; set; }

    public virtual ICollection<Group> Groups { get; set; }
    public virtual  ICollection<Location> Locations { get; set; }
}

public class UsersController : ApiController
{
    public IEnumerable<User> GetAllUser()
    {
        using (var repoProvider = new RepositoryProvider())
        {
            return repoProvider.Get<UserRepository>().GetAll();
        }
    }
}

我们如何看待用户拥有通用集合属性。当我尝试启动应用程序时出现此错误

<Error>

<Message>An error has occurred.</Message>

<ExceptionMessage>The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.</ExceptionMessage>

<ExceptionType>System.InvalidOperationException</ExceptionType>

<StackTrace/>

<InnerException>

<Message>An error has occurred.</Message>

<ExceptionMessage>Type 'System.Data.Entity.DynamicProxies.Users_0D7A537351492F8D419F58EA70B1240500CF0FFF354951D83FA225EA973C5338' with data contract name

'Employee_0D7A537351492F8D419F58EA70B1240500CF0FFF354951D83FA225EA973C5338:http://schemas.datacontract.org/2004/07/System.Data.Entity.DynamicProxies' is not

expected. Consider using a DataContractResolver or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute

attribute or by adding them to the list of known types passed to DataContractSerializer.</ExceptionMessage>

<ExceptionType>System.Runtime.Serialization.SerializationException</ExceptionType>

如何解决此问题？

Answer 1

问题可能有两个原因

您在EF中启用了动态代理，并且您向浏览器发送了一个实体，该实体没有原始类型Users，但是您可以看到名称很长的动态类在异常消息中：Users_0D7A53..
实体未配置为使用DataContractSerializer进行（反）序列化（即不可序列化）

第一种解决方案是在EF上禁用动态代理创建，或在查询中使用AsNoTracking扩展方法来避免生成代理。

'ObjectContent`1'类型无法序列化泛型集合

1 个答案: