我想要注册一个组件,以根据它可能解析的类来解析参数。 (这听起来有点令人困惑,所以我会举一个例子)。
这是一个使用记录器的对象:
class MyObject : IMyObject
{
public ILogger Logger;
public MyObject(ILogger logger)
{
Logger = logger;
}
}
现在,在COULD中传递的记录器在类与类之间是不同的。所以我对如何做到这一点有一个相当修补的想法:
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;
}
}
因此,当我注册Logger时,我希望能够告诉它className。我希望有一种方法可以做到这一点:
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"
我想这样做的原因是为了避免在代码中使用带有autofac的记录器注册我实现的每个类。我希望能够在xml中注册所有对象,并且只需要一个LoggerModule来添加此注册。
提前致谢!
答案 0 :(得分:14)
这就是我所做的(ILog只是我自己的log4net包装器):
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);
}
}