program.cs

来自「c#开发宝典 光盘内容。本光盘主要为书中的源程序」· CS 代码 · 共 46 行

using System;
using System.Collections.Generic;
using System.Text;

namespace Example8_7 {
    class Program {
        /// <summary>
        /// 圆的结构表示
        /// </summary>
        struct Round {
            /// <summary>
            /// 圆的半径
            /// </summary>
            public double r;

            /// <summary>
            /// 构造函数，负责初始化圆的半径
            /// </summary>
            /// <param name="x">圆的半径</param>
            public Round(double x) {
                r = x;
            }

            /// <summary>
            /// 求圆的面积
            /// </summary>
            /// <param name="r">圆的半径</param>
            /// <returns>圆的面积</returns>
            public double Area() {
                return Math.PI * r * r;
            }
        }

        static void Main(string[] args) {
            Round myRound1;
            myRound1.r = 2;
            Console.WriteLine("一号圆的面积为： {0}", myRound1.Area());

            Round myRound2 = new Round(2);
            Console.WriteLine("二号圆的面积为： {0}", myRound2.Area());

            Console.ReadLine();
        }
    }
}