如何获取变量的地址？（C#）

c#变量分为值类型和引用类型，值类型空间分配在栈上，引用类型空间分配的堆上（引用值是在栈上）；那么，如何获取变量的地址？

using System;
using System.Collections.Generic;
using System.Text;

namespace AddressOfVariable
{
    class Program
    {
        class Point
        {
            public int x;
            public int y;
        }

        static void Main(string[] args)
        {
            int number;
            //获取栈上变量的地址
            unsafe
            {
                int* p = &number;
                *p = 0xffff;
                Console.WriteLine("{0:x}", *p);
                Console.WriteLine("Address of numbe:0x{0:x}", (int)p);
            }

            string message = "Hello World!";
            //获取堆上变量的地址
            unsafe
            {
                fixed (char* p = message)
                {
                    Console.WriteLine("Address of message 0x{0:x}", (int)p);
                }
            }

            Point point = new Point();
            //获取堆上变量的地址
            unsafe
            {
                fixed (int* p = &point.x)
                {
                    Console.WriteLine("Address of point 0x{0:x}", (int)p);
                }
            }                
        }
    }
}