[英]How to inject object into WCF's IErrorHandler?
I have this situation: I have WCF service. 我有这种情况:我有WCF服务。 I'm handling all exceptions by
MyErrorHandler
with implemented interface IErrorHandler
. 我正在通过
MyErrorHandler
使用实现的接口IErrorHandler
处理所有异常。 There whole working code is below. 整个工作代码如下。
What I want to do, but have no idea how: I want to inject an object (for example ILogger) into MyErrorHandler
class. 我想做什么,但不知道如何做:我想将一个对象(例如ILogger)注入
MyErrorHandler
类。 It basically means I have to inject an object here: [GlobalErrorHandlerBehaviour(typeof(MyErrorHandler))]
. 这基本上意味着我必须在这里注入一个对象:
[GlobalErrorHandlerBehaviour(typeof(MyErrorHandler))]
。 Could you please help me solve this problem? 您能帮我解决这个问题吗?
[ServiceContract]
public interface ITestService
{
[OperationContract]
int GetTest();
}
[GlobalErrorHandlerBehaviour(typeof(MyErrorHandler))]
public class TestService : ITestService
{
public TestService(ILogger logger)
{
// Here, I'm already injecting logger.
// It's not imported for my question so I removed it for now
}
public int GetTest()
{
throw new Exception("Test");
}
}
// This is attribute added to TestService class
// How can I inject (via constructor) ILogger, or any other class??
public class GlobalErrorHandlerBehaviourAttribute : Attribute, IServiceBehavior
{
private readonly Type errorHandlerType;
public GlobalErrorHandlerBehaviourAttribute(Type errorHandlerType)
{
this.errorHandlerType = errorHandlerType;
}
public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
{
}
public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
IErrorHandler handler = (IErrorHandler)Activator.CreateInstance(errorHandlerType);
foreach(ChannelDispatcherBase channelDispatcherBase in serviceHostBase.ChannelDispatchers)
{
ChannelDispatcher channelDispatcher = channelDispatcherBase as ChannelDispatcher;
if (channelDispatcher != null)
{
channelDispatcher.ErrorHandlers.Add(handler);
}
}
}
public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
}
}
public class MyErrorHandler : IErrorHandler
{
//--------------------------------------------------//
// I MUST INJECT ILOGGER HERE (or any other object) //
//--------------------------------------------------//
public bool HandleError(Exception error)
{
return true;
}
public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
FaultException fe = new FaultException();
MessageFault message = fe.CreateMessageFault();
fault = Message.CreateMessage(version, message, null);
}
}
Btw. 顺便说一句。 I want to use DI and inject something in
IErrorHandler
I don't want to use private static readonly
method with logger. 我想使用DI并在
IErrorHandler
注入一些内容, IErrorHandler
我不想在IErrorHandler
中使用private static readonly
方法。
This question is related to yours. 这个问题与您有关。 Basically, you don't need
GlobalErrorHandlerBehaviourAttribute
. 基本上,您不需要
GlobalErrorHandlerBehaviourAttribute
。 You can add behaviour to your service manually. 您可以手动将行为添加到服务中。 What you have to do is to create your
ServiceHost
. 您要做的就是创建
ServiceHost
。 In this answer I explained more explicitly how to do it. 在此答案中,我更明确地说明了如何执行此操作。
Here is the working code of host application, that has injected ILogger
into IErrorHandler
: 这是将
ILogger
注入IErrorHandler
的主机应用程序的工作代码:
using System;
using System.Collections.ObjectModel;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
namespace ConsoleHost
{
class Program
{
static void Main(string[] args)
{
var logger = new DummyLogger();
var errorHandler = new TestErrorHandler(logger);
ServiceHost host = new TestServiceHost(errorHandler, typeof(TestService), new Uri("net.tcp://localhost:8002"));
host.Open();
Console.WriteLine("Press enter to exit");
Console.ReadKey();
}
}
[ServiceContract]
public interface ITestService
{
[OperationContract]
string Test(int input);
}
public class TestService : ITestService
{
public string Test(int input)
{
throw new Exception("Test exception!");
}
}
public class TestErrorHandler : IErrorHandler
{
private ILogger Logger { get; }
public TestErrorHandler(ILogger logger)
{
Logger = logger;
}
public bool HandleError(Exception error)
{
Logger.Log(error.Message);
return true;
}
public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
FaultException fe = new FaultException();
MessageFault message = fe.CreateMessageFault();
fault = Message.CreateMessage(version, message, null);
}
}
public class TestServiceHost : ServiceHost
{
private readonly IErrorHandler errorHandler;
public TestServiceHost(IErrorHandler errorHandler, Type serviceType, params Uri[] baseAddresses)
: base(serviceType, baseAddresses)
{
this.errorHandler = errorHandler;
}
protected override void OnOpening()
{
Description.Behaviors.Add(new ErrorHandlerBehaviour(errorHandler));
base.OnOpening();
}
class ErrorHandlerBehaviour : IServiceBehavior, IErrorHandler
{
private readonly IErrorHandler errorHandler;
public ErrorHandlerBehaviour(IErrorHandler errorHandler)
{
this.errorHandler = errorHandler;
}
bool IErrorHandler.HandleError(Exception error)
{
return errorHandler.HandleError(error);
}
void IErrorHandler.ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
errorHandler.ProvideFault(error, version, ref fault);
}
void IServiceBehavior.ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
foreach (ChannelDispatcher channelDispatcher in serviceHostBase.ChannelDispatchers)
{
channelDispatcher.ErrorHandlers.Add(this);
}
}
void IServiceBehavior.AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
{
}
void IServiceBehavior.Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
}
}
}
// Dummy logger
public interface ILogger
{
void Log(string input);
}
public class DummyLogger : ILogger
{
public void Log(string input) => Console.WriteLine(input);
}
}
Config: 配置:
<system.serviceModel>
<services>
<service name="ConsoleHost.TestService">
<endpoint address="net.tcp://localhost:8002/TestService"
binding="netTcpBinding"
contract="ConsoleHost.ITestService" />
</service>
</services>
</system.serviceModel>
This is interesting question but setting up DI container is not that straight forward in WCF. 这是一个有趣的问题,但是在WCF中设置DI容器并不是那么简单。 You have perform following setup:
您已执行以下设置:
See the complete code sample on MSDN for how to setup DI in WCF . 有关如何在WCF中设置DI的信息,请参见MSDN上的完整代码示例。 Once DI is setup you just need to change the ErrorHandler implementation to use ILogger via constructor injection:
设置DI后,您只需更改ErrorHandler实现即可通过构造函数注入使用ILogger:
public class MyErrorHandler : IErrorHandler
{
private ILogger logger;
public MyErrorHandler(ILogger logger)
{
this.logger = logger;
}
}
Here's an additional source for more options of setting up InstanceProvider with another type of DI. 这里有一个额外的来源与另一种类型的DI的建立InstanceProvider更多的选择。
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