解耦 ErrorHandlerAttribute 從服務實現註冊

要為所有服務分離和重用相同的錯誤記錄程式碼，你需要兩個樣板類並將它們放在某個庫的某個庫中。

ErrorhandlerAttribute 實現 IServiceBehavior。FaultErrorhandler 實現 IErrorhandler，記錄所有異常。

[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)
    {
    }
}

然後在你的服務實現中新增在 FaultErrorHandler 的 Type 例項中傳遞的 ErrorHandler 屬性。ErrorHandler 將從呼叫 HandleError 的型別構造一個例項。

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