class class1
{
public static void Main(string[] args)
{
//使用多态求矩形面积与周长和圆的面积与周长
Shape cl = new Circle();
double clarea = cl.GetArea();
double clpar = cl.GetPerimeter();
Console.WriteLine("这个圆的面积是{0},周长是{1}", Math.Round(clarea, ), Math.Round(clpar, )); Shape sq = new Square(, );
double sqarea = sq.GetArea();
double sqpar = sq.GetPerimeter();
Console.WriteLine("这个方形的面积是{0},周长是{1}", Math.Round(sqarea, ), Math.Round(sqpar, ));
Console.ReadKey();
} } //声明一个抽像类
public abstract class Shape
{
public abstract double GetArea();
public abstract double GetPerimeter();
} class Circle:Shape
{
private double _r; public double R
{
get {
return _r;
}
set {
_r = value;
}
} public Circle(double r)
{
this.R = r;
}
public override double GetArea()
{
return Math.PI * this.R * this.R;
} public override double GetPerimeter()
{
return * Math.PI * this.R;
}
} class Square : Shape
{
private double _height;
private double _width; public double Height
{
get
{
return _height;
}
set
{
_height = value;
}
} public double Width
{
get {
return _width;
}
set {
_width = value;
}
}
public Square(double w, double h)
{
this.Height = h;
this.Width = w;
}
public override double GetArea()
{
return this.Width * this.Height;
} public override double GetPerimeter()
{
return (this.Width + this.Height) * ;
}
}