C#练习4

//错误的程序
using System;
class Test
{
    unsafe static void WriteLocations(byte[]arr)
    {
        fixed(byte*p_arr=arr)
        {
            byte* p_elem = p_arr;
            for(int i=0;i<arr.Length;i++)
                byte value=*p_elem;
            string addr=int.Format((int)p_elem,"x");
            Console.WriteLine("arr[{0}]at0x{1}is{2}",i,addr,value);
            p_elem++;
        }
    }
}
static void Main()
{
byte[]Array=new byte[]{1,2,3,4,5};
WriteLocations(arr);
}

static void Main()
{
F();
G();
{
H();
I();
}
}

static void Main(String[]args)
{
if(args.Length==0)
goto done;
Console.WriteLine(args.Length);
done:
Console.WriteLine("Done");
}

static void Main()
{
const float pi=3.14;
const int r=123;
Console.WriteLine(pi*i*i);
}

static void Main()
{
int a;
int b=2,c=3;
a=1;
Console.WriteLine(a+b+c);
}

static int F

using System;
class MyClass
{
    public MyClass()
    {
        Console.WriteLine("Constructor");
    }
    public MyClass(int value)
    {
        MyField = value;
        Console.WriteLine("Destructor");
    }
    ~MyClass()
    {
        Console.WriteLine("Destructor");
    }
    public const int MyConst = 12;
    public int MyField = 34;
    public void MyMethod()
    {
        Console.WriteLine("MyClass.MyMethod");
    }
    public int Myproperty()
    {
        get{
            return MyField;
        }
        set{
            MyField=value;
        }
    }
    public int this[int index]{
        get
        {
            return 0;
        }
        set
        {
            Console.WriteLine("this[{0}]{1}", index, value);
        }
    }
    public event EventHandler MyEvent;
    public static MyClass operator+(MyClass a,MyClass b)
    {
        return new MyClass(a.MyField + b.MyField);
    }
    internal class MyNestedClass { }
   
}

class Constans
{
    public const int A = 1;
    public const int B = A + 1;
}

class Test
{
    static void Main()
    {
        Console.WriteLine("{0},{1}", Constans.A, Constans.B);
    }
}

//Fields
class Color
{
    internal ushort redpart;
    internal ushort bluepart;
    internal ushort greenpart;
    public Color(ushort red,ushort blue,ushort green)
    {
        redpart = red;
        bluepart = blue;
        greenpart = green;
    }
}

class Color
{
    public static Color Red = new Color(0XFF, 0, 0);
    public static Color Blue = new Color(0, 0XFF, 0);
    public static Color Green = new Color(0, 0, 0XFF);
    public static Color While = new Color(0, 0, 0);
}

using System;
class Point
{
    public double x, y;
    public Point(){
    this.x=0;
    this.y=0;
}
public Point(double x,double y)
    {
        this.x = x;
        this.y = y;
    }
    public static double Distance(Point a,Point b)
{
    double xdiff = a.x - b.x;
    double ydiff = a.y - b.y;
    return Math.Sqrt(xdiff * xdiff + ydiff * ydiff);
}
    public override string ToString()
    {
        return string.Format("{0},{1}",x,y);
    }
}
class Test
{
    static void Main()
    {
        Point a = new Point();
        Point b = new Point(3, 4);
        double d = Point.Distance(a, b);
        Console.WriteLine("Distance from {0} to {1} is {2}", a, b, d);
    }
}

using System;
class Point
{
    public double x, y;
    public Point(double x, double y) {
        this.x = x;
        this.y = y; 
    }
    ~Point()
    {
        Console.WriteLine("Destructed {0}", this);
    }
    public override string ToString()
    {
        return string.Format("{0},{1}",x,y);
    }
}

using System;
class Test
{
    static void Main()
    {
        Type type = typedef(Class1);
        object[] arr = type.GetCustomAttributes(typeof(HelpAttribute));
        if (arr.Length == 0)
            Console.WriteLine("Class1 has no Help attribute.");
        else
        {
            HelpAttribute ha = (HelpAttribute)arr[0];
            Console.WriteLine("Ur1={0},Topic={1}", ha.Ur1, ha.Topic);
        }
    }
}

using System;
class Test
{
    static void Main()
    {
        Type type = typedef(Class1);
        object[] arr = type.GetCustomAttributes(typeof(HelpAttribute));
        if (arr.Length == 0)
            Console.WriteLine("Class1 has no Help attribute.");
        else
        {
            HelpAttribute ha = (HelpAttribute)arr[0];
            Console.WriteLine("Ur1={0},Topic={1}", ha.Ur1, ha.Topic);
        }
    }
}