new作為修飾符
using System;
namespace Anytao.net.My_Must_net
{
    class Number
    {
        public static int i = 123;

        public void ShowInfo()
        {
            Console.WriteLine("base class---");
        }

        public virtual void ShowNumber()
        {
            Console.WriteLine(i.ToString());
        }
    }

    class IntNumber : Number
    {
        new public static int i = 456;

        public new virtual void ShowInfo()
        {
            Console.WriteLine("Derived class---");
        }

        public override void ShowNumber()
        {
            Console.WriteLine("Base number is {0}", Number.i.ToString());
            Console.WriteLine("New number is {0}", i.ToString());            
        }
    }

    class Tester
    {
        public static void Main(string[] args)
        {
            Number num = new Number();
            num.ShowNumber();
            IntNumber intNum = new IntNumber();
            intNum.ShowNumber();

            Number number = new IntNumber();
            //究竟調用了誰？
            number.ShowInfo();
            //究竟調用了誰？
            number.ShowNumber();
        }
    }
}

class Genericer<T> where T : new()
{
    public T GetItem()
    {
        return new T();
    }
}

Code
class MyCls
{
    private string _name;

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }

    public MyCls()
    {
        _name = "Emma";
    }
}

Code
class MyGenericTester
{
    public static void Main(string[] args)
    {
        Genericer<MyCls> MyGen = new Genericer<MyCls>();
        Console.WriteLine(MyGen.GetItem().Name);
    }
}