编辑代码

using System;

namespace FirstTry {
    class Rectangle {
        double length;
        double width;
        public void Acceptdetails(){
            length=7;
            width=5;
        }
        public double GetArea(){
            return length*width;
        }
        public void Display(){
            Console.WriteLine("length:{0}",length);
            Console.WriteLine("width:{0}",width);
            Console.WriteLine("Area:{0}",GetArea());
        }
    }
    class ExecuteRectangle{
        static void Main(string[]args){
            Rectangle r=new Rectangle();
            r.Acceptdetails();
            r.Display();
            Console.ReadLine();

        }
    }
}