C#study(temp)

//实例化的几种方式：
new
FileStream fs = File.Creat("data.inp");
使用反射(ReFlection)

public class Math
{
 public const double PI = 3.14059;//constants

are implicitly static
 public static double Pow(double x,double y)
 {...}
...
}

//只读字段与常量字段
public static readonly double Price = 3.72;

//alias（别名）
using BT = TeamX.BusinessTier;
.
.
.
BT.Customer c;
c = new BT.Customer(...);