日期格式化
格式化字符串的方法：《String.Format（）》
日期格式化的参考：《标准日期和时间格式字符串》
日期类型的格式化中，长格式与短格式指操作系统的区域选项的格式设置。
date formatting
Date formats are very dependant on the culture information passed. The examples below are shown using the UK culture.
specifier type output
(June 8, 1970 12:30:59)d Short Date 08/06/1970 D Long Date 08 June 1970 t Short Time 12:30 T Long Time 12:30:59 f Full date and time 08 June 1970 12:30 F Full date and time (long) 08 June 1970 12:30:59 g Default date and time 08/06/1970 12:30 G Default date and time (long) 08/06/1970 12:30:59 M Day / Month 8 June r RFC1123 date string Mon, 08 Jun 1970 12:30:59 GMT s Sortable date/time 1970-06-08T12:30:59 u Universal time, local timezone 1970-06-08 12:30:59Z Y Month / Year June 1970 custom date formatting
specifier type output
(June 8, 1970 12:30:59)dd Day 08 ddd Short Day Name Mon dddd Full Day Name Monday hh 2 digit hour 12 HH 2 digit hour (24 hour) 12 mm 2 digit minute 30 MM Month 06 MMM Short Month name Jun MMMM Month name June ss seconds 59 tt AM/PM PM yy 2 digit year 70 yyyy 4 digit year 1970 : seperator, e.g. {0:hh:mm:ss} 12:30:59 / seperator, e.g. {0:dd/MM/yyyy} 08/06/1970
文件大小格式化
写了3个扩展方法，用来将long类型格式化成1024为权的字节表示法。
使用方法：
long size=10000000000;
string r1=size.FormatFileSize();
string r2=size.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.KB);
string r3=size.FormatFileSizeWithoutUnit(MyExtendMethod.FormatFileSizeUnit.KB);
结果分别为：
r1: "9 GB"
r2: "9,765,625 KB"
r3: "9,765,625"
源码和演示
using System; class Test { static void Main() { TestDateTimeFormat(); TestFormatFileSize(); } static void TestDateTimeFormat() { DateTimeOffset now= DateTimeOffset.Now; //DateTimeOffset Console.WriteLine("{0}",now.DateTime); //DateTime Console.WriteLine("{0}",now); Console.WriteLine("{0}: {1:d}","d",now); Console.WriteLine("{0}: {1:D}","D",now); Console.WriteLine("{0}: {1:t}","t",now); Console.WriteLine("{0}: {1:T}","T",now); Console.WriteLine("{0}: {1:f}","f",now); Console.WriteLine("{0}: {1:F}","F",now); Console.WriteLine("{0}: {1:g}","g",now); Console.WriteLine("{0}: {1:G}","G",now); Console.WriteLine("{0}: {1:M}","M",now); Console.WriteLine("{0}: {1:r}","r",now); Console.WriteLine("{0}: {1:s}","s",now); Console.WriteLine("{0}: {1:u}","u",now); Console.WriteLine("{0}: {1:Y}","Y",now); Console.WriteLine(); } static void TestFormatFileSize() { long[] l={1012,1012101,1012101210,101210121012,1012101210121012}; for(int i=0;i<l.Length;i++) Console.WriteLine(l[i].FormatFileSize()); Console.WriteLine(); long m=10000000000; Console.WriteLine(m.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.Bytes)); Console.WriteLine(m.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.KB)); Console.WriteLine(m.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.MB)); Console.WriteLine(m.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.GB)); Console.WriteLine(m.FormatFileSize(MyExtendMethod.FormatFileSizeUnit.TB)); Console.WriteLine(); } } //扩展方法 public static class MyExtendMethod { /// <summary> /// 将文件大小格式化为指定单位的字符串（结果不带单位符号） /// </summary> /// <param name="size"></param> /// <param name="unit"></param> /// <returns></returns> public static string FormatFileSizeWithoutUnit(this long size, FormatFileSizeUnit unit) { string result; switch (unit) { case FormatFileSizeUnit.KB: { double d = size / 1024f; result = string.Format("{0:#,##0.##}", d > 1 ? d : 1); } break; case FormatFileSizeUnit.MB: { double d = size / 1048576f; result = string.Format("{0:#,##0.##}", d > 1 ? d : 1); } break; case FormatFileSizeUnit.GB: { double d = size / 1073741824f; result = string.Format("{0:#,##0.##}", d > 1 ? d : 1); } break; case FormatFileSizeUnit.TB: { double d = size / 1099511627776f; result = string.Format("{0:#,##0.##}", d > 1 ? d : 1); } break; case FormatFileSizeUnit.Bytes: default: result = string.Format("{0:#,##0}", size); break; } return result; } /// <summary> /// 将文件大小格式化为指定单位的字符串 /// </summary> /// <param name="size"></param> /// <param name="unit"></param> /// <returns></returns> public static string FormatFileSize(this long size, FormatFileSizeUnit unit) { string result = FormatFileSizeWithoutUnit(size, unit); switch (unit) { case FormatFileSizeUnit.KB: result += " KB"; break; case FormatFileSizeUnit.MB: result += " MB"; break; case FormatFileSizeUnit.GB: result += " GB"; break; case FormatFileSizeUnit.TB: result += " TB"; break; case FormatFileSizeUnit.Bytes: default: result += " 字节"; break; } return result; } /// <summary> /// 将文件大小自动格式化为字符串 /// </summary> /// <param name="size"></param> /// <returns></returns> public static string FormatFileSize(this long size) { if (size < 1024) return FormatFileSize(size, FormatFileSizeUnit.Bytes); if (size < 1048576) return FormatFileSize(size, FormatFileSizeUnit.KB); if (size < 1073741824) return FormatFileSize(size, FormatFileSizeUnit.MB); if (size < 1099511627776) return FormatFileSize(size, FormatFileSizeUnit.GB); return FormatFileSize(size, FormatFileSizeUnit.TB); } public enum FormatFileSizeUnit { Bytes = 0, KB, MB, GB, TB } }