ASp.net vnext中的AssemblyNeutral属性

我最近遇到AssemblyNeutral了ASP.net vnext的属性。

如果需要具体说明，那么您将在“日志记录”存储库中找到该属性的用法。https://github.com/aspnet/logging

还有许多其他存储库，但这很简单。

现在，根据许多博客，如果我们使用AssemblyNeutral属性，那么该接口或类型不与程序集绑定，因此我们可以AssemblyNeutral在其他需要相同合同的框架中定义具有属性的相同接口。

因此，创建示例我在ASP.net vnext类库项目中创建了自己的小型记录器库，但是它给我造成类型转换错误。

 namespace MyLogger
{
    #if ASPNET50 || ASPNETCORE50
    [Microsoft.Framework.Runtime.AssemblyNeutral]
    #endif
    public interface ILogger
    {      
        void Write(LogLevel logLevel, int eventId, object state, Exception exception, Func<object, Exception, string> formatter);
        bool IsEnabled(LogLevel logLevel);
        IDisposable BeginScope(object state);
    }

    #if ASPNET50 || ASPNETCORE50
    [Microsoft.Framework.Runtime.AssemblyNeutral]
    #endif
    public interface ILoggerFactory
    {       
        ILogger Create(string name);
        void AddProvider(ILoggerProvider provider);
    }
    #if ASPNET50 || ASPNETCORE50
    [Microsoft.Framework.Runtime.AssemblyNeutral]
    #endif
    public interface ILoggerProvider
    {        
        ILogger Create(string name);
    }

    #if ASPNET50 || ASPNETCORE50
    [Microsoft.Framework.Runtime.AssemblyNeutral]
    #endif
    public enum LogLevel
    {
        Verbose = 1,
        Information = 2,
        Warning = 3,
        Error = 4,
        Critical = 5,
    }

    public class MyLogger : ILogger
    {
        public IDisposable BeginScope(object state)
        {
            return null;  
        }

        public bool IsEnabled(LogLevel logLevel)
        {
            return true;
        }

        public void Write(LogLevel logLevel, int eventId, object state, Exception exception, Func<object, Exception, string> formatter)
        {
            System.IO.File.AppendAllText("C:\\Testlog.txt", "This is test log" + System.Environment.NewLine);
        }
    }

    public class MyLoggerProvider : ILoggerProvider
    {
        private readonly Func<string, LogLevel, bool> _filter;

        public MyLoggerProvider(Func<string, LogLevel, bool> filter)
        {
            _filter = filter;
        }

        public ILogger Create(string name)
        {
            return new MyLogger();
        }       
    }

    public static class MyLoggerExtentions
    {
        public static ILoggerFactory AddMyLogger(this ILoggerFactory factory, Func<string, LogLevel, bool> filter)
        {
            factory.AddProvider(new MyLoggerProvider(filter));
            return factory;
        }
    }
}

现在，我尝试在SampleApp（日志存储库SampleApp）中使用。您可以看到它给了我投射错误。为什么这样 ？