c# tostring()格式的详细解释参见文档
| Format specifier | Name | Description | Examples |
|---|---|---|---|
| "C" or "c" | Currency | Result: A currency value. Supported by: All numeric types. Precision specifier: Number of decimal digits. Default precision specifier: Defined by NumberFormatInfo.CurrencyDecimalDigits. More information: The Currency ("C") Format Specifier. |
123.456 ("C", en-US) -> $123.46 123.456 ("C", fr-FR) -> 123,46 € 123.456 ("C", ja-JP) -> ¥123 -123.456 ("C3", en-US) -> ($123.456) -123.456 ("C3", fr-FR) -> -123,456 € -123.456 ("C3", ja-JP) -> -¥123.456 |
| "D" or "d" | Decimal | Result: Integer digits with optional negative sign. Supported by: Integral types only. Precision specifier: Minimum number of digits. Default precision specifier: Minimum number of digits required. More information: The Decimal("D") Format Specifier. |
1234 ("D") -> 1234 -1234 ("D6") -> -001234 |
| "E" or "e" | Exponential (scientific) | Result: Exponential notation. Supported by: All numeric types. Precision specifier: Number of decimal digits. Default precision specifier: 6. More information: The Exponential ("E") Format Specifier. |
1052.0329112756 ("E", en-US) -> 1.052033E+003 1052.0329112756 ("e", fr-FR) -> 1,052033e+003 -1052.0329112756 ("e2", en-US) -> -1.05e+003 -1052.0329112756 ("E2", fr-FR) -> -1,05E+003 |
| "F" or "f" | Fixed-point | Result: Integral and decimal digits with optional negative sign. Supported by: All numeric types. Precision specifier: Number of decimal digits. Default precision specifier: Defined by NumberFormatInfo.NumberDecimalDigits. More information: The Fixed-Point ("F") Format Specifier. |
1234.567 ("F", en-US) -> 1234.57 1234.567 ("F", de-DE) -> 1234,57 1234 ("F1", en-US) -> 1234.0 1234 ("F1", de-DE) -> 1234,0 -1234.56 ("F4", en-US) -> -1234.5600 -1234.56 ("F4", de-DE) -> -1234,5600 |
| "G" or "g" | General | Result: The more compact of either fixed-point or scientific notation. Supported by: All numeric types. Precision specifier: Number of significant digits. Default precision specifier: Depends on numeric type. More information: The General ("G") Format Specifier. |
-123.456 ("G", en-US) -> -123.456 -123.456 ("G", sv-SE) -> -123,456 123.4546 ("G4", en-US) -> 123.5 123.4546 ("G4", sv-SE) -> 123,5 -1.234567890e-25 ("G", en-US) -> -1.23456789E-25 -1.234567890e-25 ("G", sv-SE) -> -1,23456789E-25 |
| "N" or "n" | Number | Result: Integral and decimal digits, group separators, and a decimal separator with optional negative sign. Supported by: All numeric types. Precision specifier: Desired number of decimal places. Default precision specifier: Defined by NumberFormatInfo.NumberDecimalDigits. More information: The Numeric ("N") Format Specifier. |
1234.567 ("N", en-US) -> 1,234.57 1234.567 ("N", ru-RU) -> 1 234,57 1234 ("N1", en-US) -> 1,234.0 1234 ("N1", ru-RU) -> 1 234,0 -1234.56 ("N3", en-US) -> -1,234.560 -1234.56 ("N3", ru-RU) -> -1 234,560 |
| "P" or "p" | Percent | Result: Number multiplied by 100 and displayed with a percent symbol. Supported by: All numeric types. Precision specifier: Desired number of decimal places. Default precision specifier: Defined by NumberFormatInfo.PercentDecimalDigits. More information: The Percent ("P") Format Specifier. |
1 ("P", en-US) -> 100.00 % 1 ("P", fr-FR) -> 100,00 % -0.39678 ("P1", en-US) -> -39.7 % -0.39678 ("P1", fr-FR) -> -39,7 % |
| "R" or "r" | Round-trip | Result: A string that can round-trip to an identical number. Supported by: Single, Double, and BigInteger. Note: Recommended for the BigInteger type only. For Double types, use "G17"; for Single types, use "G9". Precision specifier: Ignored. More information: The Round-trip ("R") Format Specifier. |
123456789.12345678 ("R") -> 123456789.12345678 -1234567890.12345678 ("R") -> -1234567890.1234567 |
| "X" or "x" | Hexadecimal | Result: A hexadecimal string. Supported by: Integral types only. Precision specifier: Number of digits in the result string. More information: The HexaDecimal ("X") Format Specifier. |
255 ("X") -> FF -1 ("x") -> ff 255 ("x4") -> 00ff -1 ("X4") -> 00FF |
| Any other single character | Unknown specifier | Result: Throws a FormatException at run time. |
其它各种的tostring()格式做法，详见https://docs.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings
| Format specifier | Description | Examples |
|---|---|---|
| "d" | Short date pattern. More information:The short date ("d") format specifier. |
2009-06-15T13:45:30 -> 6/15/2009 (en-US) 2009-06-15T13:45:30 -> 15/06/2009 (fr-FR) 2009-06-15T13:45:30 -> 2009/06/15 (ja-JP) |
| "D" | Long date pattern. More information:The long date ("D") format specifier. |
2009-06-15T13:45:30 -> Monday, June 15, 2009 (en-US) 2009-06-15T13:45:30 -> 15 июня 2009 г. (ru-RU) 2009-06-15T13:45:30 -> Montag, 15. Juni 2009 (de-DE) |
| "f" | Full date/time pattern (short time). More information: The full date short time ("f") format specifier. |
2009-06-15T13:45:30 -> Monday, June 15, 2009 1:45 PM (en-US) 2009-06-15T13:45:30 -> den 15 juni 2009 13:45 (sv-SE) 2009-06-15T13:45:30 -> Δευτέρα, 15 Ιουνίου 2009 1:45 μμ (el-GR) |
| "F" | Full date/time pattern (long time). More information: The full date long time ("F") format specifier. |
2009-06-15T13:45:30 -> Monday, June 15, 2009 1:45:30 PM (en-US) 2009-06-15T13:45:30 -> den 15 juni 2009 13:45:30 (sv-SE) 2009-06-15T13:45:30 -> Δευτέρα, 15 Ιουνίου 2009 1:45:30 μμ (el-GR) |
| "g" | General date/time pattern (short time). More information: The general date short time ("g") format specifier. |
2009-06-15T13:45:30 -> 6/15/2009 1:45 PM (en-US) 2009-06-15T13:45:30 -> 15/06/2009 13:45 (es-ES) 2009-06-15T13:45:30 -> 2009/6/15 13:45 (zh-CN) |
| "G" | General date/time pattern (long time). More information: The general date long time ("G") format specifier. |
2009-06-15T13:45:30 -> 6/15/2009 1:45:30 PM (en-US) 2009-06-15T13:45:30 -> 15/06/2009 13:45:30 (es-ES) 2009-06-15T13:45:30 -> 2009/6/15 13:45:30 (zh-CN) |
| "M", "m" | Month/day pattern. More information: The month ("M", "m") format specifier. |
2009-06-15T13:45:30 -> June 15 (en-US) 2009-06-15T13:45:30 -> 15. juni (da-DK) 2009-06-15T13:45:30 -> 15 Juni (id-ID) |
| "O", "o" | round-trip date/time pattern. More information: The round-trip ("O", "o") format specifier. |
DateTime values: 2009-06-15T13:45:30 (DateTimeKind.Local) --> 2009-06-15T13:45:30.0000000-07:00 2009-06-15T13:45:30 (DateTimeKind.Utc) --> 2009-06-15T13:45:30.0000000Z 2009-06-15T13:45:30 (DateTimeKind.Unspecified) --> 2009-06-15T13:45:30.0000000 DateTimeOffset values: 2009-06-15T13:45:30-07:00 --> 2009-06-15T13:45:30.0000000-07:00 |
| "R", "r" | RFC1123 pattern. More information: The RFC1123 ("R", "r") format specifier. |
2009-06-15T13:45:30 -> Mon, 15 Jun 2009 20:45:30 GMT |
| "s" | Sortable date/time pattern. More information: The sortable ("s") format specifier. |
2009-06-15T13:45:30 (DateTimeKind.Local) -> 2009-06-15T13:45:30 2009-06-15T13:45:30 (DateTimeKind.Utc) -> 2009-06-15T13:45:30 |
| "t" | Short time pattern. More information: The short time ("t") format specifier. |
2009-06-15T13:45:30 -> 1:45 PM (en-US) 2009-06-15T13:45:30 -> 13:45 (hr-HR) 2009-06-15T13:45:30 -> 01:45 م (ar-EG) |
| "T" | Long time pattern. More information: The long time ("T") format specifier. |
2009-06-15T13:45:30 -> 1:45:30 PM (en-US) 2009-06-15T13:45:30 -> 13:45:30 (hr-HR) 2009-06-15T13:45:30 -> 01:45:30 م (ar-EG) |
| "u" | Universal sortable date/time pattern. More information: The universal sortable ("u") format specifier. |
With a DateTime value: 2009-06-15T13:45:30 -> 2009-06-15 13:45:30Z With a DateTimeOffset value: 2009-06-15T13:45:30 -> 2009-06-15 20:45:30Z |
| "U" | Universal full date/time pattern. More information: The universal full ("U") format specifier. |
2009-06-15T13:45:30 -> Monday, June 15, 2009 8:45:30 PM (en-US) 2009-06-15T13:45:30 -> den 15 juni 2009 20:45:30 (sv-SE) 2009-06-15T13:45:30 -> Δευτέρα, 15 Ιουνίου 2009 8:45:30 μμ (el-GR) |
| "Y", "y" | Year month pattern. More information: The year month ("Y") format specifier. |
2009-06-15T13:45:30 -> June 2009 (en-US) 2009-06-15T13:45:30 -> juni 2009 (da-DK) 2009-06-15T13:45:30 -> Juni 2009 (id-ID) |
| Any other single character | Unknown specifier. | Throws a run-time FormatException. |
