如何配置WCF已知类型的编程？

Question

我的客户机/服务器应用程序使用WCF进行通信，这已经很大。然而当前的体系结构的一个缺点是，我必须使用的已知类型的配置对于某些类型的发送。我使用一个内部的发布/订阅机制和这个要求是不可避免的。

的问题是，它很容易忘记添加已知的类型，如果你这样做，WCF默默的一些线索，以什么地方出了错失败。

在我的申请，我所知道的集合，将要发送的类型。我想，通过它目前包含像这样的App.config文件编程方式执行的构成，而不是声明：

<system.runtime.serialization>
  <dataContractSerializer>
    <declaredTypes>
      <add type="MyProject.MyParent, MyProjectAssembly">
        <knownType type="MyProject.MyChild1, MyProjectAssembly"/>
        <knownType type="MyProject.MyChild2, MyProjectAssembly"/>
        <knownType type="MyProject.MyChild3, MyProjectAssembly"/>
        <knownType type="MyProject.MyChild4, MyProjectAssembly"/>
        <knownType type="MyProject.MyChild5, MyProjectAssembly"/>
      </add>
    </declaredTypes>
  </dataContractSerializer>
</system.runtime.serialization>

相反，我想要做的是这样的：

foreach (Type type in _transmittedTypes)
{
    // How would I write this method?
    AddKnownType(typeof(MyParent), type);
}

有人可以解释我怎么可以这样做？

修改请理解，我试图在运行时动态地设置公知的类型，而不是在声明性配置或在源代码中使用的属性。

这基本上是一个关于WCF API，而不是一个风格问题的问题。

修改2 此MSDN页页面状态：

  

您还可以类型添加到所述ReadOnlyCollection，通过的DataContractSerializer的KnownTypes属性访问。

不幸的是这一切都表示，并没有做出非常多的意义因为KnownTypes是一个只读属性，属性的值是一个ReadOnlyCollection。

Answer 1

将 [ServiceKnownType] 您[ServiceContract]接口：

[ServiceKnownType("GetKnownTypes", typeof(KnownTypesProvider))]

然后创建类称为KnownTypesProvider：

internal static class KnownTypesProvider
{
    public static IEnumerable<Type> GetKnownTypes(ICustomAttributeProvider provider)
    {
         // collect and pass back the list of known types
    }
}

和然后就可以传回你需要的任何类型的

Answer 2

有来解决问题2种的其他方式：

予。使用KnownTypeAttribute（字符串）：

[DataContract]
[KnownType("GetKnownTypes")]
public abstract class MyParent
{
    static IEnumerable<Type> GetKnownTypes()
    {
        return new Type[] { typeof(MyChild1), typeof(MyChild2), typeof(MyChild3) };
    }
}

II。使用构造的DataContractSerializer

[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class | 
                AttributeTargets.Interface)]
public class MyHierarchyKnownTypeAttribute : Attribute, IOperationBehavior, IServiceBehavior, IContractBehavior
{
    private void IOperationBehavior.AddBindingParameters(
            OperationDescription description, 
            BindingParameterCollection parameters)
    {
    }

    void IOperationBehavior.ApplyClientBehavior(
            OperationDescription description, 
            ClientOperation proxy)
    {
        ReplaceDataContractSerializerOperationBehavior(description);
    }

    private void IOperationBehavior.ApplyDispatchBehavior(
            OperationDescription description, 
            DispatchOperation dispatch)
    {
        ReplaceDataContractSerializerOperationBehavior(description);
    }

    private void IOperationBehavior.Validate(OperationDescription description)
    {
    }

    private void IServiceBehavior.AddBindingParameters(
          ServiceDescription serviceDescription,
          ServiceHostBase serviceHostBase,
          System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints,
          BindingParameterCollection bindingParameters)
    {
        ReplaceDataContractSerializerOperationBehavior(serviceDescription);
    }

    private void IServiceBehavior.ApplyDispatchBehavior(
            ServiceDescription serviceDescription, 
            ServiceHostBase serviceHostBase)
    {
        ReplaceDataContractSerializerOperationBehavior(serviceDescription);
    }

    private void IServiceBehavior.Validate(ServiceDescription serviceDescription,
            ServiceHostBase serviceHostBase)
    {
    }

    private void IContractBehavior.AddBindingParameters(
            ContractDescription contractDescription,
            ServiceEndpoint endpoint, 
            BindingParameterCollection bindingParameters)
    {
    }

    private void IContractBehavior.ApplyClientBehavior(
            ContractDescription contractDescription,
            ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        ReplaceDataContractSerializerOperationBehavior(contractDescription);
    }

    private void IContractBehavior.ApplyDispatchBehavior(
            ContractDescription contractDescription,
            ServiceEndpoint endpoint, DispatchRuntime dispatchRuntime)
    {
        ReplaceDataContractSerializerOperationBehavior(contractDescription);
    }

    private void IContractBehavior.Validate(ContractDescription contractDescription,
            ServiceEndpoint endpoint)
    {
    }    

    private static void ReplaceDataContractSerializerOperationBehavior(
            ServiceDescription description)
    {
        foreach (var endpoint in description.Endpoints)
        {
            ReplaceDataContractSerializerOperationBehavior(endpoint);
        }
    }

    private static void ReplaceDataContractSerializerOperationBehavior(
            ContractDescription description)
    {
        foreach (var operation in description.Operations)
        {
            ReplaceDataContractSerializerOperationBehavior(operation);
        }
    }

    private static void ReplaceDataContractSerializerOperationBehavior(
            ServiceEndpoint endpoint)
    {
        // ignore mex
        if (endpoint.Contract.ContractType == typeof(IMetadataExchange))
        {
            return;
        }
        ReplaceDataContractSerializerOperationBehavior(endpoint.Contract);
    }

    private static void ReplaceDataContractSerializerOperationBehavior(
            OperationDescription description)
    {
        var behavior = 
         description.Behaviors.Find<DataContractSerializerOperationBehavior>();
        if (behavior != null)
        {
            description.Behaviors.Remove(behavior);
            description.Behaviors.Add(
                new ShapeDataContractSerializerOperationBehavior(description));
        }
    }

    public class ShapeDataContractSerializerOperationBehavior 
            : DataContractSerializerOperationBehavior
    {
        public ShapeDataContractSerializerOperationBehavior(
                OperationDescription description)
            : base(description) { }

        public override XmlObjectSerializer CreateSerializer(Type type, 
                string name, string ns, IList<Type> knownTypes)
        {
            var shapeKnownTypes = 
                new List<Type> { typeof(Circle), typeof(Square) };
            return new DataContractSerializer(type, name, ns, shapeKnownTypes);
        }

        public override XmlObjectSerializer CreateSerializer(Type type, 
                XmlDictionaryString name, XmlDictionaryString ns, 
                IList<Type> knownTypes)
        {
            //All magic here!
            var knownTypes = 
                new List<Type> { typeof(MyChild1), typeof(MyChild2), typeof(MyChild3) };
            return new DataContractSerializer(type, name, ns, knownTypes);
        }
    }
}

[ServiceContract()]
[MyHierarchyKnownTypeAttribute]
public interface IService {...}

请注意：必须使用两面这个属性：客户端和服务端

Answer 3

我需要做的是为了让继承正常工作。我不想有保有派生类型的列表。

 [KnownType("GetKnownTypes")]
 public abstract class BaseOperationResponse
 {

    public static Type[] GetKnownTypes()
    {
        Type thisType = System.Reflection.MethodBase.GetCurrentMethod().DeclaringType;
        return thisType.Assembly.GetTypes().Where(t => t.IsSubclassOf(thisType)).ToArray();
    }

我知道该函数的第一行是矫枉过正，但它只是意味着我可以将其粘贴到任何基类而无需修改。

Answer 4

网络.CONFIG

<applicationSettings>
<HostProcess.Properties.Settings>
<setting name="KnowTypes" serializeAs="Xml">
<value>
 <ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <string>a.AOrder,a</string>
   <string>b.BOrder,b</string>
   <string>c.COrder,c</string>
 </ArrayOfString>
</value>
</setting>
</HostProcess.Properties.Settings>

static class Helper
{
    public static IEnumerable<Type> GetKnownTypes(ICustomAttributeProvider provider)
    {
        System.Collections.Generic.List<System.Type> knownTypes =
        new System.Collections.Generic.List<System.Type>();
        // Add any types to include here.
        Properties.Settings.Default.KnowTypes.Cast<string>().ToList().ForEach(type =>
            {
                knownTypes.Add(Type.GetType(type));
            });

        return knownTypes;
    }
}


[ServiceContract]
[ServiceKnownType("GetKnownTypes", typeof(Helper))]
public interface IOrderProcessor
{
    [OperationContract]
    string ProcessOrder(Order order);
}

---

该命令是抽象基类

---

[DataContract]
public abstract class Order
{
    public Order()
    {
        OrderDate = DateTime.Now;
    }
    [DataMember]
    public string OrderID { get; set; }
    [DataMember]
    public DateTime OrderDate { get; set; }
    [DataMember]
    public string FirstName { get; set; }
    [DataMember]
    public string LastName { get; set; }
}

Answer 5

有点大材小用，但作品是一种面向未来的

var knownTypes =
    AppDomain.CurrentDomain
    .GetAssemblies()
    .Where(a =>
    {
        var companyAttribute = a.GetCustomAttribute<AssemblyCompanyAttribute>();
        if (companyAttribute == null) return false;
        return companyAttribute.Company.ToLower().Contains("[YOUR COMPANY NAME]");
    })
    .SelectMany(a => a.GetTypes()).Where(t => t.IsSerializable && !t.IsGenericTypeDefinition);

var serializer = new DataContractSerializer(type, knownTypes);