Monotouch 4.0.6：使用 WCF 服务时出现序列化错误

我正在运行 Mono 2.10，并且刚刚升级到 Monotouch 4.0.

我的应用程序发生错误：

System.NullReferenceException: Object reference not set to an instance of an object
  at System.ServiceModel.Dispatcher.BaseMessagesFormatter.DeserializeReply (System.ServiceModel.Channels.Message message, System.Object[] parameters) [0x000e3] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs:281 
  at System.ServiceModel.Dispatcher.OperationFormatter.DeserializeReply (System.ServiceModel.Channels.Message message, System.Object[] parameters) [0x00000] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs:89 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Request (System.ServiceModel.Description.OperationDescription od, System.Object[] parameters) [0x001cb] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:552 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.DoProcess (System.Reflection.MethodBase method, System.String operationName, System.Object[] parameters) [0x00038] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:482 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Process (System.Reflection.MethodBase method, System.String operationName, System.Object[] parameters) [0x00000] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:462

这是怎么回事？谢谢。

附：使用之前版本的 MT (3.2.6)，代码可以完美运行。

更新1：

我已经重新编译了该应用程序。现在例外情况如下：

System.Net.WebException: There was an error on processing web request: Status code 400(BadRequest): Bad Request
  at System.ServiceModel.Channels.HttpRequestChannel+HttpChannelRequestAsyncResult.WaitEnd () [0x0003b] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:435 
  at System.ServiceModel.Channels.HttpRequestChannel.EndRequest (IAsyncResult result) [0x00029] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:289 
  at System.ServiceModel.Channels.HttpRequestChannel.Request (System.ServiceModel.Channels.Message message, TimeSpan timeout) [0x00000] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:63 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Request (System.ServiceModel.Channels.Message msg, TimeSpan timeout) [0x0000b] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:562 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Request (System.ServiceModel.Description.OperationDescription od, System.Object[] parameters) [0x00066] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:517

更新2：

我正在运行单声道版本 2.10.5 和 MT 4.0.6。我正在使用 WCF 并尝试调用外部 Web 服务。

我使用以下代码片段来调用 WS：

CustomBinding custom = new CustomBinding(new BinaryMessageEncodingBindingElement(),
    new HttpTransportBindingElement()
    {
       MaxReceivedMessageSize = 2147483647,
       MaxBufferSize = 2147483647
    }
);                  

EndpointAddress endpoint = new EndpointAddress(myUrl);
client = new MyServiceClient(custom, endpoint);

这个异常被捕获：

System.Net.WebException: There was an error on processing web request: Status code 400(BadRequest): Bad Request
  at System.ServiceModel.Channels.HttpRequestChannel+HttpChannelRequestAsyncResult.WaitEnd () [0x0003b] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:435 
  at System.ServiceModel.Channels.HttpRequestChannel.EndRequest (IAsyncResult result) [0x00029] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:289 
  at System.ServiceModel.Channels.HttpRequestChannel.Request (System.ServiceModel.Channels.Message message, TimeSpan timeout) [0x00000] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/HttpRequestChannel.cs:63 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Request (System.ServiceModel.Channels.Message msg, TimeSpan timeout) [0x0000b] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:562 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Request (System.ServiceModel.Description.OperationDescription od, System.Object[] parameters) [0x00066] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:517 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.DoProcess (System.Reflection.MethodBase method, System.String operationName, System.Object[] parameters) [0x00038] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:482 
  at System.ServiceModel.MonoInternal.ClientRuntimeChannel.Process (System.Reflection.MethodBase method, System.String operationName, System.Object[] parameters) [0x00000] in /Developer/MonoTouch/Source/mono/mcs/class/System.ServiceModel/System.ServiceModel/ClientRuntimeChannel.cs:462

如果我使用 basicHttpBinding 什么也不会发生。该消息似乎在网络中丢失了。

client = new MyServiceClient(new BasicHttpBinding(BasicHttpSecurityMode.None), new EndpointAddress(myUrl + "/basic"));

从 WS 返回的结构包含 MyClass 元素的列表。 MyClass 类已标记为 [DataContract attribute]，成员已标记为 [DataMember] 属性。如果服务仅返回字符串、整数或枚举，则结果正常。

注意：使用单声道版本 2.10 和 MT 3.2.6，WS 在两种情况下都可以工作。

有什么建议么？先感谢您。