类的继承和类之间的转换

namespace CSharpClass
{
class Person
{
private int age;
private string name;
public Person()//构造函数没有返回值，名称跟类名一样；
{
this.age = 20;
this.name = "chengyuan";
}
public int Age
{
get
{
return 30;
}
}
}
/// <summary>
/// 创建了两个继承的子类
/// </summary>
class Chinese : Person
{
private string hukou;
}
class Japenese : Person
{
private string Zone;
}
class Program
{
static void Main(string[] args)
{
Person p = new Person();
Console.WriteLine(p.Age );
Chinese c = new Chinese();
Person p1 = c;
//Chinese c1=p;这是错误的；
Chinese c2 = (Chinese)p;//（显示转换也是可以的）//如果转换失败，则抛出异常
Chinese c3 = p as Chinese;//as 转换如果失败，返回值是null
Console .ReadKey ();
}
}
}