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。

 // Hello1.cs
 public class Hello1
 {
    public static void Main()
    {
       System.Console.WriteLine("Hello, World!");
    }
 }

 // Hello3.cs
 // arguments: A B C D
 using System;

 public class Hello3
 {
    public static void Main(string[] args)
    {
       Console.WriteLine("Hello, World!");
       Console.WriteLine("You entered the following {0} command line arguments:",
          args.Length );
       for (int i=; i < args.Length; i++)
       {
          Console.WriteLine("{0}", args[i]);
       }
    }
 }

 // Hello4.cs
 using System;

 public class Hello4
 {
    public static int Main(string[] args)
    {
       Console.WriteLine("Hello, World!");
       return ;
    }
 }

2、通过foreach语句来遍历容器。

 // cmdline2.cs
 // arguments: John Paul Mary
 using System;

 public class CommandLine2
 {
    public static void Main(string[] args)
    {
        Console.WriteLine("Number of command line parameters = {0}",
           args.Length);
        foreach(string s in args)
        {
           Console.WriteLine(s);
        }
    }
 }

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.

 //多维数组
 string[,] names;

 //数组的数组
 byte[][] scores;

 int[] numbers = new int[];
 string[,] names = new string[,];

 //初始化数组的数组
 byte[][] scores = new byte[][];
 for (int x = ; x < scores.Length; x++)
 {
    scores[x] = new byte[];
 }

5、数组的多种初始化.

 // 初始化一维数组
 int[] numbers = new int[] {, , , , };
 string[] names = new string[] {"Matt", "Joanne", "Robert"};

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

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

 // 初始化二维数组
 int[,] numbers = new int[, ] { {, }, {, }, {, } };
 string[,] siblings = new string[, ] { {"Mike","Amy"}, {"Mary","Albert"} };

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

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

 // 初始化交错数组
 int[][] numbers = new int[][] { new int[] {,,}, new int[] {,,,,} };

 int[][] numbers = new int[][] { new int[] {,,}, new int[] {,,,,} };

 int[][] numbers = { new int[] {,,}, new int[] {,,,,} };

6、访问数组成员.

 int[,] numbers = { {, }, {, }, {, }, {, }, {, } };
 numbers[, ] = ;

 // 访问交错数组
 numbers[][] = ;
 numbers[][] = ;

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.

 int[,] numbers = new int[, ] {{, }, {, }, {, }};
 foreach(int i in numbers)
 {
    Console.Write("{0} ", i);
 }

8、通过以下方式定义属性.

     private string myName ="N/A";
     private int myAge = ;

     // Declare a Name property of type string:
     public string Name
     {
         get
         {
            return myName;
         }
         set
         {
            myName = value;
         }
     }

     // Declare an Age property of type int:
     public int Age
     {
         get
         {
            return myAge;
         }
         set
         {
            myAge = value;
         }
     }

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