class1.cs

C#2005 实例源代码

using System;

namespace Example_IShape
{
	/// <summary>
	/// 接口：形状
	/// </summary>
	public interface IShape
	{
		/// <summary>
		/// 方法：求面积
		/// </summary>
		/// <returns></returns>
		double GetArea();
	}

	/// <summary>
	/// 矩形类
	/// </summary>
	public class Rectangle: IShape
	{
		public double dblWidth;		//宽
		public double dblHeitht;	//高

		/// <summary>
		/// 构造函数
		/// </summary>
		/// <param name="_dblWidth">宽</param>
		/// <param name="_dblHeight">高</param>
		public Rectangle(double _dblWidth,double _dblHeight)
		{
			this.dblWidth=_dblWidth;
			this.dblHeitht=_dblHeight;
		}

		/// <summary>
		/// 求矩形面积
		/// </summary>
		/// <returns>面积</returns>
		public double GetArea()
		{
			return this.dblHeitht*this.dblWidth;
		}
	}

	/// <summary>
	/// 三角形类
	/// </summary>
	public class Triangle: IShape
	{
		public double dblEdge1;		//边1
		public double dblEdge2;		//边2
		public double dblEdge3;		//边3

		/// <summary>
		/// 构造函数
		/// </summary>
		/// <param name="_dblEdge1">边1</param>
		/// <param name="_dblEdge2">边2</param>
		/// <param name="_dblEdge3">边3</param>
		public Triangle(double _dblEdge1,double _dblEdge2,double _dblEdge3)
		{
			this.dblEdge1=_dblEdge1;
			this.dblEdge2=_dblEdge2;
			this.dblEdge3=_dblEdge3;			
		}

		/// <summary>
		/// 求三角形面积：利用海伦公式
		/// </summary>
		/// <returns>面积</returns>
		public double GetArea()
		{
			double p=(this.dblEdge1+this.dblEdge2+this.dblEdge3)/2.0;
			double area=System.Math.Sqrt(p*(p-this.dblEdge1)*(p-this.dblEdge2)*(p-this.dblEdge3));
			return area;
		}
	}

		/// <summary>
		/// 圆形类
		/// </summary>
	public class Circle: IShape
	{
		public double dblRadius;	//半径

		/// <summary>
		/// 构造函数
		/// </summary>
		/// <param name="_dblRadius">半径</param>
		public Circle(double _dblRadius)
		{
			this.dblRadius=_dblRadius;
		}

		/// <summary>
		/// 求圆面积
		/// </summary>
		/// <returns>面积</returns>
		public double GetArea()
		{
			return 3.1415*this.dblRadius*this.dblRadius;
		}
	}


	/// <summary>
	/// Class1 的摘要说明。
	/// </summary>
	class IShapeTest
	{
		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			/*
			Rectangle r=new Rectangle(3,5);
			Console.WriteLine(r.GetArea());		//15

			Triangle t=new Triangle(3,4,5);
			Console.WriteLine(t.GetArea());		//6

			Circle c=new Circle(1);
			Console.WriteLine(c.GetArea());		//pi
			//*/

			///*
			//多态
			IShape s;
			s=new Rectangle(1,2);
			Console.WriteLine(s.GetArea());

			s=new Triangle(3,4,5);
			Console.WriteLine(s.GetArea());

			s=new Circle(1);
			Console.WriteLine(s.GetArea());
			//*/
		}
	}
}