C#中的类和静态变量
静态变量用于定义常量，因为可以通过调用该类而不创建其实例来检索其值。静态变量可以在成员函数或类定义之外初始化。您也可以在类定义中初始化静态变量。
示例
using System;
namespace StaticVarApplication {
class StaticVar {
public static int num;
public void count() {
num++;
}
public int getNum() {
return num;
}
}
class StaticTester {
static void Main(string[] args) {
StaticVar s1 = new StaticVar();
StaticVar s2 = new StaticVar();
s1.count();
s1.count();
s1.count();
s2.count();
s2.count();
s2.count();
Console.WriteLine("Variable num for s1: {0}", s1.getNum());
Console.WriteLine("Variable num for s2: {0}", s2.getNum());
Console.ReadKey();
}
}
}输出结果
Variable num for s1: 6 Variable num for s2: 6
类变量是对象的属性（从设计的角度来看），并且对它们进行私有化以实现封装。这些变量只能使用公共成员函数访问。
让我们看一个例子-
示例
using System;
namespace BoxApplication {
class Box {
private double length; // Length of a box
private double breadth; // Breadth of a box
private double height; // Height of a box
public void setLength( double len ) {
length = len;
}
public void setBreadth( double bre ) {
breadth = bre;
}
public void setHeight( double hei ) {
height = hei;
}
public double getVolume() {
return length * breadth * height;
}
}
class Boxtester {
static void Main(string[] args) {
Box Box1 = new Box(); // Declare Box1 of type Box
Box Box2 = new Box();
double volume;
//声明Box2类型的Box2-
//框1规格
Box1.setLength(6.0);
Box1.setBreadth(7.0);
Box1.setHeight(5.0);
//方框2规格
Box2.setLength(12.0);
Box2.setBreadth(13.0);
Box2.setHeight(10.0);
//盒子1的体积
volume = Box1.getVolume();
Console.WriteLine("Volume of Box1 : {0}" ,volume);
//盒子2的体积
volume = Box2.getVolume();
Console.WriteLine("Volume of Box2 : {0}", volume);
Console.ReadKey();
}
}
}输出结果
Volume of Box1 : 210 Volume of Box2 : 1560