指针 PointerPlayground2 示例

using System;

namespace exercise {
    class Program {
        static unsafe void Main(string[] args) {
            //PointerPlayground2 该示例介绍指针的算术，以及结构指针和类成员指针。开始时，定义一个结构CurrencyStruct，
            //它把货币值表示为美元和美分，再定义一个等价的类CurrencyClass：

            //查看存储在栈中的项的地址
            Console.WriteLine("Szie of CurrencyStruct sturct is " + sizeof(CurrencyStruct));
            CurrencyStruct amount1, amount2;
            CurrencyStruct* pAmount = &amount1;
            long* pDollars = &pAmount->Dollars;
            byte* pCents = &(pAmount->Cents);
            Console.WriteLine("Address of amount1 is 0x{0:X}", (uint)&amount1);
            Console.WriteLine("Address of amount2 is 0x{0:X}", (uint)&amount2);
            Console.WriteLine("Address of pAmount is 0x{0:X}", (uint)&pAmount);
            Console.WriteLine("Address of pDollars is 0x{0:X}", (uint)&pAmount);
            Console.WriteLine("Address of pCents is 0x{0:X}", (uint)&pCents);
            pAmount->Dollars = 20;
            *pCents = 50;
            Console.WriteLine("amount1 contains " + amount1);

            //查看存储在堆中的项的地址
            Console.WriteLine("\nNow with classes");
            //now try it out with classes
            CurrencyClass amount3 = new CurrencyClass();
            fixed(long* pDollars2 = &amount3.Dollars)
            fixed(byte* pCents2 = &(amount3.Cents)) {
                Console.WriteLine("amount3,Dollars has address 0x{0:X}", (uint)pDollars2);
                Console.WriteLine("amount3.Cents has address 0x{0:X}", (uint)pCents2);
                *pDollars2 = -100;
                Console.WriteLine("amount3 conteans " + amount3);
            }
        }
    }

    internal struct CurrencyStruct {
        public long Dollars;
        public byte Cents;

        public override string ToString() {
            return "$" + this.Dollars + "." + this.Cents;
        }
    }

    internal class CurrencyClass {
        public long Dollars;
        public byte Cents;

        public override string ToString() {
            return "$" + this.Dollars + "." + this.Cents;
        }
    }
}