using System;

using System.Reflection;

using System.Linq;

​

public static class Program

{

    public static void Main()

    {

        var a = GetCustomAttribute<Sighs, MyAttributeForDemo>();

        Console.WriteLine(a.SomeNumber);

    }

    public static TAttribute GetCustomAttribute<TTarget, TAttribute>()

        where TAttribute : Attribute

    {

        return typeof(TTarget).GetTypeInfo().GetCustomAttributes().OfType<TAttribute>().SingleOrDefault();

    }

}

​

[MyAttributeForDemo(69)]

public class Sighs

{

}

​

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]

public class MyAttributeForDemo : Attribute

{

    public MyAttributeForDemo(int i)

    {

        SomeNumber = i;

    }

​

    public int SomeNumber { get; set; }

}

​