Autofac：注册组件和解决取决于解析父 [英] Autofac: Register component and resolve depending on resolving parent

问题描述

我想注册一个组件基于这可能是解决该类参数来解决。 （这听起来有点混乱，所以我将展示一个例子）。

I'm wanting to register a component to resolve with parameters based on the class that it might be resolving for. (That sounds a bit confusing, so I'll show an example).

下面是一个使用记录器的对象：

Here's an object that uses a logger:

class MyObject : IMyObject
{
    public ILogger Logger;
    public MyObject(ILogger logger)
    {
        Logger = logger;
    }
}

现在传递的可能是从类类不同的记录。所以，我已经得到了如何做一个相当补丁的想法如下：

Now the logger that is passed in COULD be different from class to class. So I've got a rather patched idea for how to do that below:

class MyLogger : ILogger
{
    public string Name{get; protected set;}

    public static ILogger GetLogger(string className)
    {
        Name = className;
        MyLogger logger;
        // Do something to choose a logger for that specific class
        return logger;
    }
}

所以，当我注册的Logger我希望能够告诉它的类名。我希望有办法做到这一点类似于这样：

So when I register Logger I want to be able to tell it the className. I'm hoping there's a way to do it similar to this:

ContainerBuilder builder = new ContainerBuilder();

builder.Register<MyLogger>(ctx =>
    {
        string className = //Get resolving class name somehow;
        return MyLogger.GetLogger(className);
    }).As<ILogger>();

builder.Register<MyObject>().As<IMyObject>();

var container = builder.Build();

IMyObject myObj = container.Resolve<IMyObject>();

//myObject.Logger.Name should now == "MyObject"

我想这样做，这种方式的原因是为了避免登记各班我在code autofac记录器实现。我希望能够注册所有的XML对象，并简单地有LoggerModule，添加此注册。

The reason I want to do it this way is to avoid registering each class I implement with a logger with autofac in code. I want to be able to register all of the objects in xml, and simply have a LoggerModule, that adds this registration.

在此先感谢！

推荐答案

下面是我做的（ILog的只是我身边的log4net自己的包装）：

Here's what I do (ILog is just my own wrapper around log4net):

public class LoggingModule : Module
{
    protected override void Load(ContainerBuilder builder)
    {
        builder.Register((c, p) => GetLogger(p.TypedAs<Type>()));
    }

    protected override void AttachToComponentRegistration(
        IComponentRegistry registry, IComponentRegistration registration)
    {
        registration.Preparing +=
            (sender, args) =>
            {
                var forType = args.Component.Activator.LimitType;

                var logParameter = new ResolvedParameter(
                    (p, c) => p.ParameterType == typeof (ILog),
                    (p, c) => c.Resolve<ILog>(TypedParameter.From(forType)));

                args.Parameters = args.Parameters.Union(new[] {logParameter});
            };
    }

    public static ILog GetLogger(Type type)
    {
        return new Log4NetLogger(type);
    }
}

public interface ILog
{
    void Debug(string format, params object[] args);
    void Info(string format, params object[] args);
    void Warn(string format, params object[] args);

    void Error(string format, params object[] args);
    void Error(Exception ex);
    void Error(Exception ex, string format, params object[] args);

    void Fatal(Exception ex, string format, params object[] args);
}

public class Log4NetLogger : ILog
{
    private readonly log4net.ILog _log;

    static Log4NetLogger()
    {
        XmlConfigurator.Configure();
    }

    public Log4NetLogger(Type type)
    {
        _log = LogManager.GetLogger(type);
    }

    public void Debug(string format, params object[] args)
    {
        _log.DebugFormat(format, args);
    }

    public void Info(string format, params object[] args)
    {
        _log.InfoFormat(format, args);
    }

    public void Warn(string format, params object[] args)
    {
        _log.WarnFormat(format, args);
    }

    public void Error(string format, params object[] args)
    {
        _log.ErrorFormat(format, args);
    }

    public void Error(Exception ex)
    {
        _log.Error("", ex);
    }

    public void Error(Exception ex, string format, params object[] args)
    {
        _log.Error(string.Format(format, args), ex);
    }

    public void Fatal(Exception ex, string format, params object[] args)
    {
        _log.Fatal(string.Format(format, args), ex);
    }
}

这篇关于Autofac：注册组件和解决取决于解析父的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！