C# 基础

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace Test
 8 {
 9     public enum TimeOfDay
10     {
11         Morning = 0,
12         Afternoon = 1,
13         Evening = 2
14     }
15     class Program
16     {
17         static void Main(string[] args)
18         {
19             TimeOfDay time = TimeOfDay.Afternoon;
20             Console.WriteLine(time.ToString()); //输出：Afternoon
21 
22             TimeOfDay time2 = (TimeOfDay)Enum.Parse(typeof(TimeOfDay), "afternoon", true);
23             Console.WriteLine((int)time2);
24         }
25     }
26 }
27 //Enum.Parse(枚举类型，需转换的字符串，bool(是否忽略大小写)),返回对象（此处TimeOfDay.Afternoon），需显示转换。

1 int[] arrays = new int[32];
2 Console.WriteLine(arrays.Length);//返回数组长度
3 
4 int[] arrays2;
5 Console.WriteLine(arrays2.Length);//报错

1 using System;
2 using Introduction = Wrox.ProCSharp.Basics;
3 
4 //...
5 
6 Introduction::NamespaceExample NSEx = new Introduction::NamespaceExample(); //命名空间别名修饰符::

1 int i = 730;
2 int j = 73;
3 Console.WriteLine("{0,4}\n+{1,4}\n----\n{2,4}", i, j, i + j);
4 decimal m = 940.23m;
5 decimal n = 73.7m;
6 Console.WriteLine("{0,9:C2}\n+{1,9:C2}\n------\n{2,9:C2}", m, n, m + n);
7 //{x,y:z} x表示参数索引，y表示宽度值（正值右对齐，负值左对齐），z表示格式字符串，如C2表示精度到小数点后两位或者{x,y:#.00}

1 //类中所有私有成员字段的名称
2 public int subscriberId;
3 
4 //成员字段通常下划线开始
5 public int _subscriberId;
6 
7 //传递的形参数
8 public void RecordSale(string salemanName, int quantity);