C# Keynote

【C# Keynote】

1、 Main 方法必须包含在一个类内，参数类型、返回值类型可以有多种变化。

 1 // Hello1.cs

 2 public class Hello1

 3 {

 4    public static void Main()

 5    {

 6       System.Console.WriteLine("Hello, World!");

 7    }

 8 }

 9 

10 // Hello3.cs

11 // arguments: A B C D

12 using System;

13 

14 public class Hello3

15 {

16    public static void Main(string[] args)

17    {

18       Console.WriteLine("Hello, World!");

19       Console.WriteLine("You entered the following {0} command line arguments:",

20          args.Length );

21       for (int i=0; i < args.Length; i++)

22       {

23          Console.WriteLine("{0}", args[i]); 

24       }

25    }

26 }

27 

28 // Hello4.cs

29 using System;

30 

31 public class Hello4

32 {

33    public static int Main(string[] args)

34    {

35       Console.WriteLine("Hello, World!");

36       return 0;

37    }

38 }

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2、通过foreach语句来遍历容器。

 1 // cmdline2.cs

 2 // arguments: John Paul Mary

 3 using System;

 4 

 5 public class CommandLine2

 6 {

 7    public static void Main(string[] args)

 8    {

 9        Console.WriteLine("Number of command line parameters = {0}",

10           args.Length);

11        foreach(string s in args)

12        {

13           Console.WriteLine(s);

14        }

15    }

16 }

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3、C# 数组从零开始建立索引，声明数组时，方括号 ([]) 必须跟在类型后面，而不是标识符后面。在 C# 中，将方括号放在标识符后是不合法的语法。

 

　　另一细节是，数组的大小不是其类型的一部分，而在 C 语言中它却是数组类型的一部分。这使您可以生成Heap上的数组。

4、声明多维数组，以及数组的数组.

 1 //多维数组

 2 string[,] names;

 3 

 4 //数组的数组

 5 byte[][] scores;

 6 

 7 int[] numbers = new int[5];

 8 string[,] names = new string[5,4];

 9 

10 //初始化数组的数组

11 byte[][] scores = new byte[5][];

12 for (int x = 0; x < scores.Length; x++) 

13 {

14    scores[x] = new byte[4];

15 }

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5、数组的多种初始化.

 1 // 初始化一维数组

 2 int[] numbers = new int[5] {1, 2, 3, 4, 5};

 3 string[] names = new string[3] {"Matt", "Joanne", "Robert"};

 4 

 5 int[] numbers = new int[] {1, 2, 3, 4, 5};

 6 string[] names = new string[] {"Matt", "Joanne", "Robert"};

 7 

 8 int[] numbers = {1, 2, 3, 4, 5};

 9 string[] names = {"Matt", "Joanne", "Robert"};

10 

11 // 初始化二维数组

12 int[,] numbers = new int[3, 2] { {1, 2}, {3, 4}, {5, 6} };

13 string[,] siblings = new string[2, 2] { {"Mike","Amy"}, {"Mary","Albert"} };

14 

15 int[,] numbers = new int[,] { {1, 2}, {3, 4}, {5, 6} };

16 string[,] siblings = new string[,] { {"Mike","Amy"}, {"Mary","Albert"} };

17 

18 int[,] numbers = { {1, 2}, {3, 4}, {5, 6} };

19 string[,] siblings = { {"Mike", "Amy"}, {"Mary", "Albert"} };

20 

21 // 初始化交错数组

22 int[][] numbers = new int[2][] { new int[] {2,3,4}, new int[] {5,6,7,8,9} };

23 

24 int[][] numbers = new int[][] { new int[] {2,3,4}, new int[] {5,6,7,8,9} };

25 

26 int[][] numbers = { new int[] {2,3,4}, new int[] {5,6,7,8,9} };

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6、访问数组成员.

1 int[,] numbers = { {1, 2}, {3, 4}, {5, 6}, {7, 8}, {9, 10} };

2 numbers[1, 1] = 5;

3 

4 // 访问交错数组

5 numbers[0][0] = 58;

6 numbers[1][1] = 667;

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7、在 C# 中，数组实际上是对象。System.Array 是所有数组类型的抽象基类型。多维数组也可以使用foreach来访问.

1 int[,] numbers = new int[3, 2] {{9, 99}, {3, 33}, {5, 55}};

2 foreach(int i in numbers)

3 {

4    Console.Write("{0} ", i);

5 }

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8、通过以下方式定义属性.

 1     private string myName ="N/A";

 2     private int myAge = 0;

 3 

 4     // Declare a Name property of type string:

 5     public string Name

 6     {

 7         get 

 8         {

 9            return myName; 

10         }

11         set 

12         {

13            myName = value; 

14         }

15     }

16 

17     // Declare an Age property of type int:

18     public int Age

19     {

20         get 

21         { 

22            return myAge; 

23         }

24         set 

25         { 

26            myAge = value; 

27         }

28     }

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参考：http://msdn.microsoft.com/zh-cn/library/aa288453(v=vs.71).aspx