21点游戏 书上的的范例，稍改了点，不够精简，只好先放着了

using System;public enum CardSuit {    Zero_Error,    梅花,    方块,    红桃,    黑桃}public enum CardValue {    Zero_Error,    Ace,    二,    三,    四,    五,    六,    七,    八,    九,    十,    Jack,    Queen,    King}struct card {    public CardSuit suit;    public CardValue val;    public int CardValue {        get {            int retval;            if ((int)this.val >= 10)                retval = 10;            else if ((int)this.val == 1)                retval = 11;            else                retval = (int)this.val;            return retval;        }    }    public override string ToString() {        return (string.Format("{0}{1}", this.suit.ToString("G"), this.val.ToString("G")));    }}class deck {    public card[] cards = new card[53];    int next;    public deck() {        next = 1;        cards[0].val = 0;        cards[0].suit = 0;        int currcard = 0;        for (int suitctr = 1; suitctr < 5; suitctr++) {            for (int valctr = 1; valctr < 14; valctr++) {                currcard = valctr + (suitctr - 1) * 13;                cards[currcard].val = (CardValue)valctr;                cards[currcard].suit = (CardSuit)suitctr;            }        }    }    public void shuffle() {        Random rnd = new Random();        int sort1;        int sort2;        card tmpcard = new card();        for (int ctr = 0; ctr < 100; ctr++) {            sort1 = (int)(rnd.NextDouble() * 52 + 1);            sort2 = (int)(rnd.NextDouble() * 52 + 1);            tmpcard = this.cards[sort1];            this.cards[sort1] = this.cards[sort2];            this.cards[sort2] = tmpcard;        }        this.next = 1;    }    public card dealCard() {        if (next > 52)            return (this.cards[0]);        else            return this.cards[next++];    }}class CardGame {    static deck mydeck = new deck();    static card[] pHand = new card[10];    static card[] cHand = new card[10];    public static void Main() {        int pCardCtr = 0;        int pTotal = 0;        int cTotal = 0;        bool playing = true;        while (playing == true) {            pTotal = 0;            cTotal = 0;            pCardCtr = 0;            for (int ctr = 0; ctr < 10; ctr++) {                pHand[ctr].val = 0;                pHand[ctr].suit = 0;            }            Console.WriteLine("\nShuffling cards...");            mydeck.shuffle();            Console.WriteLine("Dealing cards...");            pHand[0] = mydeck.dealCard();            cHand[0] = mydeck.dealCard();            pHand[1] = mydeck.dealCard();            cHand[1] = mydeck.dealCard();            cTotal = cHand[0].CardValue;            bool PlayersTurn = true;            do {                Console.WriteLine("\n玩家:");                pCardCtr = 0;                pTotal = 0;                do {                    Console.WriteLine(" Card{0}:{1}", pCardCtr + 1, pHand[pCardCtr].ToString());                    pTotal += pHand[pCardCtr].CardValue;                    pCardCtr++;                } while ((int)pHand[pCardCtr].val != 0);                Console.WriteLine("庄家:");                Console.WriteLine("Card1:{0}", cHand[0].ToString());                Console.WriteLine("====================");                Console.WriteLine("玩家 Total={0} \n庄家 Total={1}", pTotal, cTotal);                if (pTotal <= 21)                    PlayersTurn = GetPlayerOption(pCardCtr);                else                    PlayersTurn = false;            } while (PlayersTurn == true);            if (pTotal > 21)                Console.WriteLine("\n\n****BUSTED****\n");            else {                cTotal += cHand[1].CardValue;                int cCardCtr = 2;                Console.WriteLine("\n\n玩家\'s Total:{0}", pTotal);                Console.WriteLine("\nComputer:");                Console.WriteLine(" {0}", cHand[0].ToString());                Console.WriteLine(" {0} Total:{1}", cHand[1].ToString(), cTotal);                while (cTotal < 17) {                    cHand[cCardCtr] = mydeck.dealCard();                    cTotal += cHand[cCardCtr].CardValue;                    Console.WriteLine(" {0} Total:{1}", cHand[cCardCtr].ToString(), cTotal);                    cCardCtr++;                }                if (cTotal > 21) {                    Console.WriteLine("\n\nComputer Busted!");                    Console.WriteLine("YOU WON!!!");                }                else {                    if (pTotal > cTotal)                        Console.WriteLine("\n\nYOU WON!!!");                    else if (pTotal == cTotal)                        Console.WriteLine("\n\n平局");                    else                        Console.WriteLine("\n\nSorry,The Computer won");                }                Console.Write("\n\nDo you want to play again?");                string answer = Console.ReadLine();                try {                    if (answer[0] != 'y' && answer[0] != 'Y')                        playing = false;                }                catch {                    playing = false;                }            }        }    }    static bool GetPlayerOption(int cardctr) {        string buffer;        bool cont = true;        bool retval = true;        while (cont == true) {            Console.Write("\n\nH=Hit,S=Stay   ");            buffer = Console.ReadLine();            try {                if (buffer[0] == 'h' || buffer[0] == 'H') {                    pHand[cardctr] = mydeck.dealCard();                    cont = false;                }                else if (buffer[0] == 's' || buffer[0] == 'S') {                    retval = false;                    cont = false;                }                else                    Console.WriteLine("\n***Please enter an H or S and press Enter...");            }            catch {                cont = true;            }        }        return retval;    }}