实现此目的的一种方法是拦截 XML 响应并将根元素名称更改为唯一的名称,然后再对其进行反序列化。这可以通过自定义 IClientMessageFormatter 和操作上的关联属性轻松完成。
我刚刚写了这个,所以“湿油漆”等等,但看起来是这样的:
/// <summary>
/// An operation attribute that changes the XML root name in responses
/// </summary>
/// <example>
///
/// [ServiceContract]
/// [XmlSerializerFormat]
/// public interface IRedBlueServiceApi
/// {
/// [OperationContract]
/// [WebGet(...)]
/// [XmlChangeRoot("RedResponse")]
/// RedResponse GetRed();
///
/// [OperationContract]
/// [WebGet(...)]
/// [XmlChangeRoot("BlueResponse")]
/// BlueResponse GetBlue();
/// }
///
/// [XmlRoot("RedResponse")]
/// public class RedResponse
/// {...}
///
/// [XmlRoot("BlueResponse")]
/// public class BlueResponse
/// {...}
/// </example>
[DefaultProperty("NewRootElementName")]
public class XmlChangeRootAttribute : Attribute, IOperationBehavior
{
public XmlChangeRootAttribute(string newRootElementName)
{
NewRootElementName = newRootElementName;
}
public string NewRootElementName { get; set; }
#region IOperationBehavior Members
public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation)
{
// Inject our xml root changer into the client request/response pipeline
clientOperation.Formatter = new XmlRootChangeFormatter(clientOperation.Formatter, NewRootElementName);
}
#endregion
#region Unrelated Overrides
public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
{
}
public void AddBindingParameters(OperationDescription operationDescription,
BindingParameterCollection bindingParameters)
{
}
public void Validate(OperationDescription operationDescription)
{
}
#endregion
}
/// <summary>
/// A simple wrapper around an existing IClientMessageFormatter
/// that alters the XML root name before passing it along
/// </summary>
public class XmlRootChangeFormatter : IClientMessageFormatter
{
private readonly IClientMessageFormatter _innerFormatter;
private readonly string _newRootElementName;
public XmlRootChangeFormatter(IClientMessageFormatter innerFormatter, string newRootElementName)
{
if (innerFormatter == null)
throw new ArgumentNullException("innerFormatter");
if (String.IsNullOrEmpty(newRootElementName))
throw new ArgumentException("newRootElementName is null or empty");
_innerFormatter = innerFormatter;
_newRootElementName = newRootElementName;
}
#region IClientMessageFormatter Members
public Message SerializeRequest(MessageVersion messageVersion, object[] parameters)
{
return _innerFormatter.SerializeRequest(messageVersion, parameters);
}
public object DeserializeReply(Message message, object[] parameters)
{
if (!message.IsEmpty)
{
var doc = XDocument.Load(message.GetReaderAtBodyContents());
if (doc.Root == null)
throw new SerializationException("Could not find root in WCF messasge " + message);
// Change the root element name
doc.Root.Name = _newRootElementName;
// Create a new 'duplicate' message with the modified XML
var modifiedReply = Message.CreateMessage(message.Version, null, doc.CreateReader());
modifiedReply.Headers.CopyHeadersFrom(message.Headers);
modifiedReply.Properties.CopyProperties(message.Properties);
message = modifiedReply;
}
return _innerFormatter.DeserializeReply(message, parameters);
}
#endregion
}