在c#[关闭]中,最好的OOP模式是什么

代码片段不会编译,因为它只是为了展示我想要实现的目标: 假设我有一个接口:

      public Interface IWalker 
      {
          //Compiles but not what I need
          double DistanceTravelled {get; set;}

          //Compiler error - cant be private for set, but that's what I need
          //double DistanceTravelled {get; private set;}
      }

      public abstract AbstractWalker : IWalker 
      {
           //Error:Cannot implement - but thats what I need
           //protected double DistanceTravelled {get; private set} 

           //Error the set is not public and I dont want the property to be public
           //public double DistanceTravelled { get;private  set; }

             //Compiles but not what i need at all since I want a protected 
             // property -a. and have it behave as readonly - b. but 
             // need it to be a part of the interface -c.
             public double DistanceTravlled {get; set;}

      }

我所有抽象行者的具体实例实际上都是IWalker的类型。 实现我在代码片段中指定的设计的最佳方法是什么?