解耦 ErrorHandlerAttribute 从服务实现注册

要为所有服务分离和重用相同的错误记录代码，你需要两个样板类并将它们放在某个库的某个库中。

ErrorhandlerAttribute 实现 IServiceBehavior。FaultErrorhandler 实现 IErrorhandler，记录所有异常。

[AttributeUsage(AttributeTargets.Class)]
public class ErrorHandlerAttribute : Attribute, IServiceBehavior
{
    Type mErrorType;
    public ErrorHandlerAttribute(Type t)
    {
        if (!typeof(IErrorHandler).IsAssignableFrom(t))
            throw new ArgumentException("Type passed to ErrorHandlerAttribute constructor must inherit from IErrorHandler");
        mErrorType = t;
    }

    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        foreach (ChannelDispatcher dispatcher in serviceHostBase.ChannelDispatchers)
        {
            dispatcher.ErrorHandlers.Add((IErrorHandler)Activator.CreateInstance(mErrorType));
        }
    }

    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
    }
}

class FaultErrorHandler : IErrorHandler
{
    public bool HandleError(Exception error)
    {
        // LOG ERROR
        return false; // false so the session gets aborted
    }

    public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
    {
    }
}

然后在你的服务实现中添加在 FaultErrorHandler 的 Type 实例中传递的 ErrorHandler 属性。ErrorHandler 将从调用 HandleError 的类型构造一个实例。

[ServiceBehavior]
[ErrorHandler(typeof(FaultErrorHandler))]
public class MyService : IMyService
{
}