尝试使用 DataContractResolver 时找不到 DataContractSerializerOperationBehavior

Question

我正在尝试使用 DataContractResolver 作为 WCF 中 KnownTypes 的替代方法。

我有以下代码，我之前在服务器端使用过它。但是在客户端，在操作行为集合中查找DataContractSerializerOperationBehavior时，代码返回null。

public override IMyService CreateProxy(Uri url)
{
    ServiceEndpoint endpoint = CreateEndpoint(url);
    var channelFactory = new ChannelFactory<IMyService>(endpoint);
    InjectResolver(channelFactory.Endpoint);
    return channelFactory.CreateChannel();
}

private void InjectResolver(ServiceEndpoint endpoint)
{
    foreach (OperationDescription operation in endpoint.Contract.Operations)
    {
        var behavior = operation.Behaviors.Find<DataContractSerializerOperationBehavior>();
        behavior.DataContractResolver = new DerivedTypeResolver(); // behavior is null here!
    }
}

为什么缺少该行为？

更新：我发现真正的问题是 WCF 使用的是 XmlSerializer 而不是 DataContractSerializer。有没有办法强制 DataContractSerializer 代替？ WCF 是否根据 wsdl 选择序列化程序？考虑到我（还）没有能力改变服务器端，我的选择是什么？ XmlSerializer 行为似乎没有自己解决类型的类似选项。

Answer 1

请参阅此处，例如，如果 DataContractSerializerOperationBehavior 不存在，如何创建它：

private void DataContractBehavior()
{
    WSHttpBinding b = new WSHttpBinding(SecurityMode.Message);
    Uri baseAddress = new Uri("http://localhost:1066/calculator");
    ServiceHost sh = new ServiceHost(typeof(Calculator), baseAddress);
    sh.AddServiceEndpoint(typeof(ICalculator), b, "");

    // Find the ContractDescription of the operation to find.
    ContractDescription cd = sh.Description.Endpoints[0].Contract;
    OperationDescription myOperationDescription = cd.Operations.Find("Add");

    // Find the serializer behavior.
    DataContractSerializerOperationBehavior serializerBehavior =
        myOperationDescription.Behaviors.
           Find<DataContractSerializerOperationBehavior>();

    // If the serializer is not found, create one and add it.
    if (serializerBehavior == null)
    {
        serializerBehavior = new DataContractSerializerOperationBehavior(myOperationDescription);
        myOperationDescription.Behaviors.Add(serializerBehavior);
    }

    // Change the settings of the behavior.
    serializerBehavior.MaxItemsInObjectGraph = 10000;
    serializerBehavior.IgnoreExtensionDataObject = true;

    sh.Open();
    Console.WriteLine("Listening");
    Console.ReadLine();
}

来自https://msdn.microsoft.com/en-us/library/system.servicemodel.description.datacontractserializeroperationbehavior.aspx的示例