Question

我的Web API由3个类组成：CustomTask，Payment和Client。

CustomTask引用（属于）Client。

付款参考CustomTask。

我添加了测试客户端，一切都很好。但是，当我添加与此客户端关联的CustomTask时，我在Web浏览器中列出错误时出错：

<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.CustomTask_C8E7E37C41E5E531B4F79887952391B7F9896801C32E9876AA3C63332F3B5A9A' with data contract name 'CustomTask_C8E7E37C41E5E531B4F79887952391B7F9896801C32E9876AA3C63332F3B5A9A:http://schemas.datacontract.org/2004/07/System.Data.Entity.DynamicProxies' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer 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 the serializer.
</ExceptionMessage>
<ExceptionType>
System.Runtime.Serialization.SerializationException
</ExceptionType>
<StackTrace>
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiType(XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle objectTypeHandle, Type objectType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle, Type declaredType) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle) at WriteArrayOfCustomTaskToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , CollectionDataContract ) at System.Runtime.Serialization.CollectionDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.DataContractSerializer.WriteObject(XmlWriter writer, Object graph) at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content) at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken) --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.Http.WebHost.HttpControllerHandler.<WriteBufferedResponseContentAsync>d__1b.MoveNext()
</StackTrace>
</InnerException>
</Error>

我该如何解决这个问题？

修改

CustomTask.cs

public class CustomTask
{
    public CustomTask() { }

    public int ID { get; set; }

    [ForeignKey("Client")]
    [Required]
    public int ClientID { get; set; }

    public virtual Client Client { get; set; }

    [Required]
    public string Technology { get; set; }

    [Required]
    public string Name { get; set; }

    public string Description { get; set; }

    [Required]
    public DateTime CreateDate { get; set; }

    [Required]
    public DateTime DueDate { get; set; }

    [Required]
    public long EstimatedTime { get; set; }

    public long RealTime { get; set; }

    [Required]
    public decimal Price { get; set; }

    [DefaultValue(false)]
    [Required]
    public bool Finished { get; set; }

    [DefaultValue(false)]
    [Required]
    public bool Lessons { get; set; }

    public string ArchiveID { get; set; }
}

Client.cs：

public class Client
{
    public Client() { }

    public int ID { get; set; }

    [Required]
    public string Names { get; set; }

    public string Email { get; set; }

    public string Phone { get; set; }

    public string Address { get; set; }

    public string Info { get; set; }
}

我的ClientsController和CustomTasksController由Visual Studio生成。

ClientsController返回漂亮的XML，使用WinForms编写的客户端应用程序也可以顺序化，没有任何问题：

<ArrayOfClient xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/...">
<Client>
<Address/>
<Email/>
<ID>1</ID>
<Info/>
<Names>saddasdasd</Names>
<Phone/>
</Client>
<Client>
<Address/>
<Email/>
<ID>2</ID>
<Info/>
<Names>saddasdasd</Names>
<Phone/>
</Client>
</ArrayOfClient>

修改我刚刚发现，问题只发生在我的Web API部署在Azure中，本地一切正常。

修改我找到了答案，解决方案是在部署到Azure时向连接字符串添加MultipleActiveResultSets=True。

ASP.NET Web Api - 尝试列出所有对象时出错

0 个答案: