static void Main(string[] args)
{
bool endApp = false;
while (!endApp)
{
Console.WriteLine("请选择构造的形状:");
Console.WriteLine("\tc - 圆");
Console.WriteLine("\tr - 长方形");
Console.WriteLine("\ts - 正方形");
Console.WriteLine("\tt - 三角形");
string op = Console.ReadLine();
Graphical graphical = GraphicalFactory.CreateGraphical(op);
if (graphical.IsLegal())
{
graphical.area = graphical.AreaGraphical();
graphical.perimeter = graphical.PerimeterGraphical();
Console.WriteLine("该图形的面积为：" + graphical.area);
Console.WriteLine("该图形的周长为：" + graphical.perimeter);
}
else
{
Console.WriteLine("\t输入图形不合法");
}
Console.WriteLine("按“n”结束程序，或者其他键继续计算");
if (Console.ReadLine() == "n")
{
endApp = true;
}
}
}
public static Graphical CreateGraphical(String shape)
{
Graphical open = null;
switch (shape)
{
case "c": open = new Circle();
break;
case "r": open = new Rectangle();
break;
case "s": open = new Square();
break;
case "t": open = new Triangle();
break;
}
return(open);
}