IT工程師數位筆記本

/// <summary>
/// 自己做飯的情況
/// 沒有簡單工廠之前，客戶想吃什么菜只能自己炒的
/// </summary>
public class Customer
{
    /// <summary>
    /// 燒菜方法
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    public static Food Cook(string type)
    {
        Food food = null;
        // 客戶A說：我想吃西紅柿炒蛋怎么辦？
        // 客戶B說：那你就自己燒啊
        // 客戶A說： 好吧，那就自己做吧
        if (type.Equals("西紅柿炒蛋"))
        {
            food = new TomatoScrambledEggs();
        }
        // 我又想吃土豆肉絲, 這個還是得自己做
        // 我覺得自己做好累哦，如果能有人幫我做就好了？
        else if (type.Equals("土豆肉絲"))
        {
            food = new ShreddedPorkWithPotatoes();
        }
        return food;
    }
    static void Main(string[] args)
    {
        // 做西紅柿炒蛋
        Food food1 = Cook("西紅柿炒蛋");
        food1.Print();
        Food food2 = Cook("土豆肉絲");
        food1.Print();
        Console.Read();
    }
}
/// <summary>
/// 菜抽象類
/// </summary>
public abstract class Food
{
    // 輸出點了什么菜
    public abstract void Print();
}
/// <summary>
/// 西紅柿炒雞蛋這道菜
/// </summary>
public class TomatoScrambledEggs : Food
{
    public override void Print()
    {
        Console.WriteLine("一份西紅柿炒蛋！");
    }
}
/// <summary>
/// 土豆肉絲這道菜
/// </summary>
public class ShreddedPorkWithPotatoes : Food
{
    public override void Print()
    {
        Console.WriteLine("一份土豆肉絲");
    }
}

/// <summary>
/// 顧客充當客戶端，負責調用簡單工廠來生產對象
/// 即客戶點菜，廚師（相當于簡單工廠）負責燒菜(生產的對象)
/// </summary>
class Customer
{
    static void Main(string[] args)
    {
        // 客戶想點一個西紅柿炒蛋      
        Food food1 = FoodSimpleFactory.CreateFood("西紅柿炒蛋");
        food1.Print();
        // 客戶想點一個土豆肉絲
        Food food2 = FoodSimpleFactory.CreateFood("土豆肉絲");
        food2.Print();
        Console.Read();
    }
}
/// <summary>
/// 菜抽象類
/// </summary>
public abstract class Food
{
    // 輸出點了什么菜
    public abstract void Print();
}
/// <summary>
/// 西紅柿炒雞蛋這道菜
/// </summary>
public class TomatoScrambledEggs : Food
{
    public override void Print()
    {
        Console.WriteLine("一份西紅柿炒蛋！");
    }
}
/// <summary>
/// 土豆肉絲這道菜
/// </summary>
public class ShreddedPorkWithPotatoes : Food
{
    public override void Print()
    {
        Console.WriteLine("一份土豆肉絲");
    }
}
/// <summary>
/// 簡單工廠類, 負責 炒菜
/// </summary>
public class FoodSimpleFactory
{
    public static Food CreateFood(string type)
    {
        Food food = null;
        if (type.Equals("土豆肉絲"))
        {
            food = new ShreddedPorkWithPotatoes();
        }
        else if (type.Equals("西紅柿炒蛋"))
        {
            food = new TomatoScrambledEggs();
        }
        return food;
    }
}

public static Encoding GetEncoding(int codepage)
{
    Encoding unicode = null;
    if (encodings != null)
    {
        unicode = (Encoding)encodings[codepage];
    }
    if (unicode == null)
    {
        object obj2;
        bool lockTaken = false;
        try
        {
            Monitor.Enter(obj2 = InternalSyncObject, ref lockTaken);
            if (encodings == null)
            {
                encodings = new Hashtable();
            }
            unicode = (Encoding)encodings[codepage];
            if (unicode != null)
            {
                return unicode;
            }
            switch (codepage)
            {
                case 0:
                    unicode = Default;
                    break;
                case 1:
                case 2:
                case 3:
                case 0x2a:
                    throw new ArgumentException(Environment.GetResourceString("Argument_CodepageNotSupported", new object[] { codepage }), "codepage");
                case 0x4b0:
                    unicode = Unicode;
                    break;
                case 0x4b1:
                    unicode = BigEndianUnicode;
                    break;
                case 0x6faf:
                    unicode = Latin1;
                    break;
                case 0xfde9:
                    unicode = UTF8;
                    break;
                case 0x4e4:
                    unicode = new SBCSCodePageEncoding(codepage);
                    break;
                case 0x4e9f:
                    unicode = ASCII;
                    break;
                default:
                    unicode = GetEncodingCodePage(codepage);
                    if (unicode == null)
                    {
                        unicode = GetEncodingRare(codepage);
                    }
                    break;
            }
            encodings.Add(codepage, unicode);
            return unicode;
        }
}

switch (codepage)
{
    .......
    default:
    unicode = GetEncodingCodePage(codepage);
    if (unicode == null)
    {
        unicode = GetEncodingRare(codepage); //當編碼很少見時
    }
    break;
    ......
}