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String.Format格式說明

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字符

說明

示例

輸出

C 貨幣 string.Format("{0:C3}", 2) ＄2.000 D 十進制 string.Format("{0:D3}", 2) 002 E 科學計數法 1.20E+001 1.20E+001 G 常規 string.Format("{0:G}", 2) 2 N 用分號隔開的數字

="BACKGROUND-COLOR: #ffffff">string.Format("{0:N}", 250000) 250,000.00 X 十六進制 string.Format("{0:X000}", 12) C

string.Format("{0:000.000}", 12.2) 012.200

Strings

There really isn''t any formatting within a strong, beyond it''s alignment. Alignment works for any argument being printed in a String.Format call.

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:d} System.
FormatException -12400 e ScIEntific {0:e} 1.420000e+000 -1.240000e+004 f Fixed point {0:f} 1.42 -12400.00 g General {0:g} 1.42<

/td> -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:x4} 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

The group separator is especially useful for formatting currency values which require that negative values be enclosed in parentheses. This currenc

y formatting example at the bottom of this document makes it obvious:

Dates

Note that date formatting is especially dependant on the system''s regional settings; 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

ont> 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 {0:dd} 10 ddd

="2">Day name {0:ddd} Tue dddd Full day name {0:dddd} Tuesday f, ff, ... Second fractions {0:fff} 932 gg, ... Era {0:gg} 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:hh:mm:ss} 10:43:20

er">/ Separator {0:dd/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);

This will output "＄1,240.00" if passed 1243.50. It will output the same format but in parentheses if the number is negative, and will output the string "Zero" if the number is zero.

String.Format("{0:(###) ###-####}", 18005551212);

This will output "(800) 555-1212".

變量.ToString()

字符型轉換轉為字符串
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進制)
12345.ToString("p"); //生成 1,234,500.00%