设计模式之桥接模式

　　1，多重继承变化封装

　　2，桥接模式：解决多维度的变化

　　有一个手机抽象类如下：

    /// <summary>
    /// 抽象父类
    /// </summary>
    public abstract class BasePhone
    {
        /// <summary>
        /// 操作系统
        /// </summary>
        public abstract string System();

        /// <summary>
        /// 系统版本
        /// </summary>
        public abstract string Version();
        /// <summary>
        /// 打电话
        /// </summary>
        public abstract void Call();
        /// <summary>
        /// 发短信
        /// </summary>
        public abstract void Text();
    }

　　（1）现在我们想要一个iPhone和Galaxy，则需要代码如下：

 public class iPhone : BasePhone
    {
        public override string System()
        {
            return "IOS";
        }
        public override string Version()
        {
            return "9.3";
        }
        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.System(), this.Version());
        }

        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.System(), this.Version());
        }
    }

    public class Galaxy:BasePhone
    {
        public override string System()
        {
            return "Android";
        }

        public override string Version()
        {
            return "6.0";
        }

        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.System(), this.Version());
        }

        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.System(), this.Version());
        }
    }

　　调用如下：

            {
                BasePhone phone=new iPhone();
                phone.Call();
                phone.Text();
            }
            {
                BasePhone phone=new Galaxy();
                phone.Call();
                phone.Text();
            }

　　（2）如果现在我们想要刷机，将iPhone手机装Android系统，将Galaxy装IOS系统，则需要代码如下：

  /// <summary>
    /// 使用Android系统的iPhone手机
    /// </summary>
    public class iPhoneAndroid:BasePhone
    {
        public override string System()
        {
            return "Android";
        }

        public override string Version()
        {
            return "6.0";
        }

        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.System(), this.Version());
        }

        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.System(), this.Version());
        }
    }

    public class GalaxyIOS : BasePhone
    {
        public override string System()
        {
            return "IOS";
        }
        public override string Version()
        {
            return "9.3";
        }
        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.System(), this.Version());
        }

        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.System(), this.Version());
        }
    }

　　如果还有其它系统的手机，比如WinPhone，则每一款手机将会有iPhone,iPhoneAndroid,iPhoneWinPhone，如果操作系统为M，手机类型为N，则需要多的类的个数为M*N，随着系统和手机类型的增加，将会造成类泛滥，所以现在将变化进行封装，

　　（3）桥接模式

　　代码如下：

    public interface ISystem
    {
        string System();
        string Version();
    }

    public class AndroidSystem : ISystem
    {
        public string System()
        {
            return "Android";
        }
        public string Version()
        {
            return "6.0";
        }
    }

    public class IOSSystem: ISystem
    {
        public string System()
        {
            return "IOS";
        }
        public string Version( )
        {
            return "9.3";
        }
    }

    public class WinphoneSystem : ISystem
    {
        public string System()
        {
            return "Winphone";
        }
        public string Version()
        {
            return "10.0";
        }
    }

　　BasePhoneBridge:

    /// <summary>
    /// 抽象父类
    /// </summary>
    public abstract class BasePhoneBridge
    {
        /// <summary>
        /// 操作系统
        /// </summary>
        public ISystem SystemVersion { get; set; }
        ///// <summary>
        ///// 操作系统
        ///// </summary>
        //public abstract string System();

        ///// <summary>
        ///// 系统版本
        ///// </summary>
        //public abstract string Version();
        /// <summary>
        /// 打电话
        /// </summary>
        public abstract void Call();
        /// <summary>
        /// 发短信
        /// </summary>
        public abstract void Text();
    }

GalaxyBridge:

    public class GalaxyBridge : BasePhoneBridge
    {
        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
    }

　　iPhoneBridge :

    public class iPhoneBridge : BasePhoneBridge
    {
        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
    }

　　LumiaBridge:

    public class LumiaBridge : BasePhoneBridge
    {
        public override void Call()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Call", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
        public override void Text()
        {
            Console.WriteLine("Use OS{0}.{1}.{2} Text", this.GetType().Name, this.SystemVersion.System(), this.SystemVersion.Version());
        }
    }

　　调用方式：

            Console.WriteLine("**************Bridge***************");
            ISystem android = new AndroidSystem();
            ISystem ios = new IOSSystem();
            ISystem winphone = new WinphoneSystem();
            {
                BasePhoneBridge phone = new GalaxyBridge();
                phone.SystemVersion = android;
                phone.Call();
                phone.Text();
            }
            {
                BasePhoneBridge phone = new GalaxyBridge();
                phone.SystemVersion = ios;
                phone.Call();
                phone.Text();
            }
            {
                BasePhoneBridge phone = new GalaxyBridge();
                phone.SystemVersion = winphone;
                phone.Call();
                phone.Text();
            }    

　　效果：

　　此时，子类数量为操作系统M+手机类型N 个。

　　桥接模式缺点：使用麻烦，对于上端来说需要了解更多细节（需要知道怎么初始化操作系统）