获取某月的开始日期和结束日期

 1获取某月的开始日期和结束日期#region 获取某月的开始日期和结束日期
 2        /**//// <summary>
 3        /// 获取某月的开始日期和结束日期
 4        /// </summary>
 5        /// <param name="year">年份</param>
 6        /// <param name="month">月份</param>
 7        /// <param name="dtStart">开始日期</param>
 8        /// <param name="dtEnd">结束日期</param>
 9        public static void GetSedtOfMonth(int year, byte month, out DateTime dtStart, out DateTime dtEnd)
10        {
11            // 获取本月的天数
12            byte days = GetDaysOfMonth(year, month);
13            // 返回本月的开始日期和结束日期
14            dtStart = new DateTime(year, month, 1);
15            dtEnd = new DateTime(year, month, days);
16        }
17        #endregion

 1获取某月的天数#region 获取某月的天数
 2        /**//// <summary>
 3        /// 获取某月的天数
 4        /// </summary>
 5        /// <param name="year">年份</param>
 6        /// <param name="month">月份</param>
 7        /// <returns>天数</returns>
 8        public static byte GetDaysOfMonth(int year, byte month)
 9        {
10            byte days = 31;
11            switch(month)
12            {
13                case 1:
14                    days = 31;
15                    break;
16                case 3:
17                    goto case 1;
18                case 5:
19                    goto case 1;
20                case 7:
21                    goto case 1;
22                case 8:
23                    goto case 1;
24                case 10:
25                    goto case 1;
26                case 12:
27                    goto case 1;
28                case 4:
29                    days = 30;
30                    break;
31                case 6:
32                    goto case 4;
33                case 9:
34                    goto case 4;
35                case 11:
36                    goto case 4;
37                case 2:
38                    if ((year % 4 == 0 && year % 100 != 0) || year % 400 ==0)
39                    {
40                        days = 29;
41                    }
42                    else
43                    {
44                        days = 28;
45                    }
46                    break;
47                default:
48                    days = 31;
49                    break;
50            }
51            return days;
52        }
53        #endregion