字符 | 说明 | 示例 | 输出 |
| C | 货币 | string.Format("{0:C3}", 2) | ＄2.000 |
| D | 十进制 | string.Format("{0 3}", 2) | 002 |
| E | 科学计数法 | 1.20E+001 | 1.20E+001 |
| G | 常规 | string.Format("{0:G}", 2) | 2 |
| N | 用分号隔开的数字 | string.Format("{0:N}", 250000) | 250,000.00 |
| X | 十六进制 | string.Format("{0 000}", 12) | C |
| string.Format("{0:000.000}", 12.2) | 012.200 |
| Sample | Generates |
| String.Format("->{1,10}<-", "Hello"); | -> Hello<- |
| String.Format("->{1,-10}<-", "Hello"); | ->Hello <- |
Numbers Basic number formatting specifiers:
| Specifier | Type | Format | Output (Passed Double 1.42) | Output (Passed Int -12400) |
| c | Currency | {0:c} | ＄1.42 | -＄12,400 |
| d | Decimal (Whole number) | {0 } | System. FormatException | -12400 |
| e | Scientific | {0:e} | 1.420000e+000 | -1.240000e+004 |
| f | Fixed point | {0 } | 1.42 | -12400.00 |
| g | General | {0 } | 1.42 | -12400 |
| n | Number with commas for thousands | {0:n} | 1.42 | -12,400 |
| r | Round trippable | {0:r} | 1.42 | System. FormatException |
| x | Hexadecimal | {0 4} | System. FormatException | cf90 |
Custom number formatting:
| Specifier | Type | Example | Output (Passed Double 1500.42) | Note |
| 0 | Zero placeholder | {0:00.0000} | 1500.4200 | Pads with zeroes. |
| # | Digit placeholder | {0 #).##} | (1500).42 | |
| . | Decimal point | {0:0.0} | 1500.4 | |
| , | Thousand separator | {0:0,0} | 1,500 | Must be between two zeroes. |
| ,. | Number scaling | {0:0,.} | 2 | Comma adjacent to Period scales by 1000. |
| % | Percent | {0:0%} | 150042% | Multiplies by 100, adds % sign. |
| e | Exponent placeholder | {0:00e+0} | 15e+2 | Many exponent formats available. |
| ; | Group separator | see below | |
Thegroup separator is especially useful for formatting currency valueswhich require that negative values be enclosed in parentheses. Thiscurrency formatting example at the bottom of this document makes itobvious:
Dates Notethat date formatting is especially dependant on the system's regionalsettings; the example strings here are from my local locale.
| Specifier | Type | Example (Passed System.DateTime.Now) |
| d | Short date | 10/12/2002 |
| D | Long date | December 10, 2002 |
| t | Short time | 10:11 PM |
| T | Long time | 10:11:29 PM |
| f | Full date & time | December 10, 2002 10:11 PM |
| F | Full date & time (long) | December 10, 2002 10:11:29 PM |
| g | Default date & time | 10/12/2002 10:11 PM |
| G | Default date & time (long) | 10/12/2002 10:11:29 PM |
| M | Month day pattern | December 10 |
| r | RFC1123 date string | Tue, 10 Dec 2002 22:11:29 GMT |
| s | Sortable date string | 2002-12-10T22:11:29 |
| u | Universal sortable, local time | 2002-12-10 22:13:50Z |
| U | Universal sortable, GMT | December 11, 2002 3:13:50 AM |
| Y | Year month pattern | December, 2002 |
The 'U' specifier seems broken; that string certainly isn't sortable.
Custom date formatting:
| Specifier | Type | Example | Example Output |
| dd | Day | {0d} | 10 |
| ddd | Day name | {0dd} | Tue |
| dddd | Full day name | {0ddd} | Tuesday |
| f, ff, ... | Second fractions | {0ff} | 932 |
| gg, ... | Era | {0g} | A.D. |
| hh | 2 digit hour | {0:hh} | 10 |
| HH | 2 digit hour, 24hr format | {0:HH} | 22 |
| mm | Minute 00-59 | {0:mm} | 38 |
| MM | Month 01-12 | {0:MM} | 12 |
| MMM | Month abbreviation | {0:MMM} | Dec |
| MMMM | Full month name | {0:MMMM} | December |
| ss | Seconds 00-59 | {0:ss} | 46 |
| tt | AM or PM | {0:tt} | PM |
| yy | Year, 2 digits | {0:yy} | 02 |
| yyyy | Year | {0:yyyy} | 2002 |
| zz | Timezone offset, 2 digits | {0:zz} | -05 |
| zzz | Full timezone offset | {0:zzz} | -05:00 |
| : | Separator | {0 mm:ss} | 10:43:20 |
| / | Separator | {0d/MM/yyyy} | 10/12/2002 |
Enumerations
| Specifier | Type |
| g | Default (Flag names if available, otherwise decimal) |
| f | Flags always |
| d | Integer always |
| x | Eight digit hex. |
Some Useful Examples String.Format("{0:＄#,##0.00;(＄#,##0.00);Zero}", value);
Thiswill output "＄1,240.00" if passed 1243.50. It will output the sameformat but in parentheses if the number is negative, and will outputthe string "Zero" if the number is zero.String.Format("{0
###) ###-####}", 18005551212);This will output "(800) 555-1212".
变量.ToString()
字符型转换 转为字符串
12345.ToString("n"); //生成 12,345.00
12345.ToString("C"); //生成 ￥12,345.00
12345.ToString("e"); //生成 1.234500e+004
12345.ToString("f4"); //生成 12345.0000
12345.ToString("x"); //生成 3039 (16进制)
12345.ToString("p"); //生成 1,234,500.00%
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