<C#任务导引教程>练习八
//66,静态成员与非静态成员的访问方式
using System;
class Text
{
public int x;
public static int y;//静态数据成员
void F()
{
x = 1;//正确，等价于this.x=1
y = 1;//正确，等价于Text.y=1
}
static void G()//静态 函数 成员
{
// x = 1;错误，不能访问this.x
y = 1;//正确，等价于Text.y=1
}
}
class Program
{
static void Main()
{
Text t = new Text();
t.x = 1;
//t.y = 1;错误，不能在类的实例中访问静态成员
//Text.x = 1;错误，不能按类访问非静态成员
Text.y = 1;
}
}
//67,静态数据成员的定义和引用
using System;
class MyClass
{
private int A,B,C;
private static int sum;
public MyClass(int a, int b, int c)
{
A = a;
B = b;
C = c;
sum += A + B + C;
}
public void PrintMumber()
{
Console.WriteLine("{0};{1};{2}", A, B, C);
}
public int PrintSum(MyClass m)
{
return MyClass.sum;
}
}
class MainClass
{
static void Main()
{
MyClass M = new MyClass(3, 4, 5);
MyClass N = new MyClass(5, 6, 7);
M.PrintMumber();
N.PrintMumber();
//Console.WriteLine("{0};{1}", M.PrintMumber(M), N.PrintMumber(N));
Console.WriteLine("{0};{1}", M.PrintSum(M), N.PrintSum(N));
}
}
//68,使用静态方法访问静态数据成员
using System;
class M
{
private int A;
private static int B = 10;
public M(int a)
{
A = a;
B += a;
}
public static void fun(M m)
{
Console.WriteLine("A={0}", m.A);
Console.WriteLine("B={0}", B);
}
}
class MainClass
{
static void Main()
{
M P = new M(6);//对于类M中的一般非静态数据成员A是通过对象m来访问的，而对于静态数据成员B，则采用类直接访问的方式
M Q = new M(8);//对于静态方法成员的调用方式，在C#中只能用类来直接调用
M.fun(P);// 6,16
M.fun(Q);//8 18
}
}
//69,用对象成员处理有关类的问题
using System;
class A
{
char c;
public A(char m)
{
c = m;
}
public void print()
{
Console.WriteLine("c={0}", c);
}
}
class B
{
int p;
public B(char m,int n)
{
A a = new A(m);
a.print();
p = n;
}
~B() { }
public void print()
{
Console.WriteLine("p={0}", p);
}
}
class MainClass
{
static void Main()
{
B b = new B('M', 20);
b.print();
}
}
//70,结构和类的使用的对比之一
using System;
struct sPoint
{
public int x, y;
public sPoint(int a, int b)
{
x = a;
y = b;
}
}
class cPoint
{
public int x, y;
public cPoint(int a, int b)
{
x = a;
y = b;
}
}
class Program
{//在结构中将结构对象sp复制给新对象s后，开辟了各自的对象空间，即两个变量分别引用两个对象，每个变量都有自己的数据副本，操作一个
//变量不影响其他变量，在类中将对象cp复制给新对象c后，共用同一对象空间，即两个变量只引用同一个对象，操作一个变量会影响另一个变量
public static void Main()
{
sPoint sp = new sPoint(12, 12);
sPoint s = sp;
sp.x = 112;
Console.WriteLine("结构:");
Console.WriteLine("x的值: " + s.x + "\ty的值: " + s.y);
cPoint cp = new cPoint(12, 12);
cPoint c = cp;
cp.x = 112;
Console.WriteLine("类：");
Console.WriteLine("x的值: " + c.x + "\ty的值：" + c.y);
}
}
//71,结构和类的使用对比之二
using System;
class ClassPoint
{
public int x, y;
public ClassPoint(int x, int y)
{
this.x = x;
this.y = y;
}
}
struct StructPoint
{
public int x, y;
public StructPoint(int x, int y)
{
this.x = x;
this.y = y;
}
}
class Program
{//程序创建并初始化了一个含有10个点的数组，对于作为类的实现的Point，出现了11个实例对象，其中数组生命需要一个对象，他的10个元素每个都需要创建一个对象，
//然而用结构体来实现，只需要创建一个对象，如果在类中也像结构中一样，把“cp[i]=new ClassPoint”一句删去，系统会报告“未处理的异常，未将对象引用设置到对象的
//的实例,"可见，在类中必须为每个元素创建一个对象的实例，而在结构中却不需要，如果数组很大，用类和结构在处理有诸如“点”之类的问题的执行效率上，差别是非常大的
/*结构和类的差别：1，结构是值类型，他在栈区分配地址。类是引用类型，他在堆区分配地址 2，结构成员默认的访问级别是public，而类成员默认访问级别是private
3，结构不能作为基类型，类可以作为基类型 4，结构无析构函数，类有析构函数*/
static void Main()
{
ClassPoint[] cp = new ClassPoint[10];
for(int i=0;i<cp.Length;i++)
{
cp[i] = new ClassPoint(i, i);
Console.WriteLine("({0},{1})", cp[i].x, cp[i].y);
}
Console.WriteLine();
StructPoint[] sp = new StructPoint[10];
for (int i = 0; i < sp.Length; i++)
{
Console.Write("({0},{1})", sp[i].x, sp[i].y);
}
Console.WriteLine();
}
}
//72,枚举类型
using System;
class Program
{
enum Color { black, blue, yellow = 14, white };
public static void Main()
{
int a1 = (int)Color.black;
int a2 = (int)Color.blue;
int a3 = (int)Color.yellow;
int a4 = (int)Color.white;
Console.WriteLine("Black:{0}", a1);
Console.WriteLine("blue:{0}", a2);
Console.WriteLine("yellow:{0}", a3);
Console.WriteLine("white:{0}", a4);
}
}
//73,运算符重载
using System;
class Point
{
public int x = 0;
public int y = 0;
public Point(int a, int b)
{
x = a;
y = b;
}
public void Print1()
{
Console.WriteLine("第一个矢量的端点坐标是:（{0}，{1})", x, y);
}
public void Print2()
{
Console.WriteLine("第二个矢量的端点坐标是:({0},{1})", x, y);
}
public static Point operator +(Point a, Point b)
{
return new Point(a.x + b.x, a.y + b.y);
}
}
class Program
{
public static void Main()
{
Point a = new Point(3, 2);
Point b = new Point(1, 5);
Point c = a + b;
a.Print1();
b.Print2();
Console.WriteLine("两矢量的端点坐标是:" + '(' + c.x + ',' + c.y + ')');
}
}
//74,throw:抛出异常，try:捕获异常，catch:处理异常
using System;
class Program
{
public static void Main()
{
try
{
Console.WriteLine("1/2={0:F2}", Div(1, 2));
Console.WriteLine("5/3={0:F2}", Div(5,3));
Console.WriteLine("5/0={0:F2}", Div(5,0));
Console.WriteLine("10/3={0:F2}", Div(10,3));
}
catch(Exception)
{
Console.WriteLine("发现异常！");
Console.WriteLine("被零抛出！\n在除法运算中除数不能为零!");
}
Console.WriteLine("主函数结束.");
}
public static double Div(double a, double b)
{
if (b == 0)
throw new Exception();
return a / b;
}
}
//75，异常情况
using System;
class Program
{
public static void Main()
{
Console.Write("请输入编号:");
string number = Console.ReadLine();
Console.Write("请输入工资:");
double earnings = Convert.ToDouble(Console.ReadLine());
Console.Write("请输入年龄:");
int age = Convert.ToInt32(Console.ReadLine());
int f = test(number);
int g = test(earnings);
int h = test(age);
if (f == 1 && g == 1 && h == 1)
Console.WriteLine("\n编号:{0}\n工资:{1:C2}\n年龄:{2}", number, earnings, age);
}
public static int test(string p)
{
int f = 1;
try
{
if (p[0] >= '0' && p[0] <= '9')
throw new Exception();
}
catch (Exception)
{
f = 0;
Console.WriteLine("编号错误:{0}", p[0]);
}
return f;
}
public static int test(double d)
{
int g = 1;
try
{
if (d < 0 || d > 20000)
throw new Exception();
}
catch (Exception)
{
g = 0;
Console.WriteLine("工资错误:{0}", d);
}
return g;
}
public static int test(int a)
{
int w = 1;
try
{
if (a < 18 || a > 60)
throw new Exception();
}
catch (Exception)
{
w = 0;
Console.WriteLine("年龄错误:{0}", a);
}
return w;
}
}
