设计模式》享元模式

字体 享元

    public class FontFlyWeight
    {
        //享元对象标识，用于作为存入键值对中的键值
        public const string NAME = "";
        private char fontContent;

        public char FontContent
        {
            get => fontContent;
            set => fontContent = value;
        }

        public FontFlyWeight(char font)
        {
            fontContent = font;
        }

        public string SetColor(string color)
        {
            Console.WriteLine($"将当前字体{FontContent}的字体颜色设置为{color}");
            return color;
        }

        public string SetSize(string size)
        {
            Console.WriteLine($"将当前字体{FontContent}的字体大小设置为{size}");
            return size;
        }
    }

    public class FontA : FontFlyWeight
    {
        public new const string NAME = "FontA";
        public FontA(char font) : base(font)
        {
        }
    }

    public class FontB : FontFlyWeight
    {
        public new const string NAME = "FontB";
        public FontB(char font) : base(font)
        {
        }
    }

    public class FontFactory
    {
        private static FontFactory m_instance;

        public static FontFactory GetInstance
        {
            get
            {
                if (m_instance == null)
                {
                    m_instance = new FontFactory();
                }
                return m_instance;
            }
        }

        private FontFactory()
        {
            AddFont(FontA.NAME, new FontA('a'));
            AddFont(FontB.NAME, new FontB('b'));
        }
        
        private Dictionary<string, FontFlyWeight> m_fontDic =
            new Dictionary<string, FontFlyWeight>();

        public void AddFont(string fontName, FontFlyWeight font)
        {
            if (m_fontDic.ContainsKey(fontName))
            {
                m_fontDic[fontName] = font;
            }
            else
            {
                m_fontDic.Add(fontName, font);
            }
        }

        public FontFlyWeight FindFont(string fontName)
        {
            if (m_fontDic.ContainsKey(fontName))
            {
                return m_fontDic[fontName];
            }

            return null;
        }

        public void RemoveFont(string fontName)
        {
            if (m_fontDic.ContainsKey(fontName))
            {
                m_fontDic.Remove(fontName);
            }
        }
    }


       static void Main(string[] args)
        {
            FontFlyWeight a, b;
            a = FontFactory.GetInstance.FindFont(FontA.NAME);
            
            var aa = FontFactory.GetInstance.FindFont(FontA.NAME);
            if (a.GetHashCode().Equals(aa.GetHashCode()))
            {
                Console.WriteLine("相同对象");
            }
     
        
        }
    }

参考地址