C# 处理异常

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

namespace Ch13CardLib
{
    public class CardOutOfRangeException : Exception
    {
        private Cards deckContents;

        public Cards DeckContents
        {
            get
            {
                return deckContents;
            }
        }

        public CardOutOfRangeException(Cards sourceDeckContents) :
            base("There are only 52 cards in the deck.")
        {
            deckContents = sourceDeckContents;
        }
    }
}

继承Exception

base("There are only 52 cards in the deck.")

触发时会传出括号中的文字信息，调用方法：

public Card GetCard(int cardNum)
        {
            if (cardNum >= 0 && cardNum <= 51)
            {
                // Code modified in section "Expanding and Using CardLib"
                if ((cardNum == 51) && (LastCardDrawn != null))
                    LastCardDrawn(this);
                return cards[cardNum];
            }
            else
                throw new CardOutOfRangeException(cards.Clone() as Cards);
        }

或者使用下面的方法调用CardOutOfRangeException ：

 Deck deck1 = new Deck();
         try
         {
             Card myCard = deck1.GetCard(60);
         }
         catch (CardOutOfRangeException e)
         {
             Console.WriteLine(e.Message);
             Console.WriteLine(e.DeckContents[0]);
         }
         Console.ReadKey();