C # in the ToString () format detailed

int.tostring (format):

The format string takes the form Axx, where a is the format specifier, specifies the format type, XX is the precision specifier, and controls the number of significant digits or decimal places for the formatted output, as follows:

Format specifier

Description	Example	Output
C	Currency	2.5.ToString ("C")	￥2.50
D	Decimal number	25.ToString ("D5")	00025
E	Scientific type	25000.ToString ("E")	2.500000E+005
F	Fixed point	25.ToString ("F2")	25.00
G	Conventional	2.5.ToString ("G")	2.5
N	Digital	2500000.ToString ("N")	2,500,000.00
P	Percentage
X	Hexadecimal	255.ToString ("X")	Ff

to use formatting in String.Format:

These structural objects can also be formatted in the String.Format method, which is contained between "{}" and separated by ":". ":" is preceded by the String.Format index value, as is the general format, and ":" is followed by the format type of these structures. If you use placeholders, you use the "," split with the index, a positive number to the right, and a negative to the left, and the absolute value represents the width of the characters, for example:

String. Format ("The value is {0,7:f3}", 123.45);
The result is: "     123.2"
//Where: 7 represents a placeholder (right-aligned), occupies 7 digits, and if use-7 is left-aligned, occupies seven digits.

Format character description
0 decimal left integer decimal right placeholder
# non-0 o'clock digit placeholder
. Decimal point
, Thousand separator
% multiplied by 100 plus% to indicate
\ escape Sequence
' String
"" String
; Split positive numbers and 0


format string data type value output
##### Double 123 123
00000 Double 123 00123
(###) ###-Double 1234567890 (123) 456–7890
#.## Double 1.2 1.2
0.00 Double 1.2 1.20
00.00 Double 1.2 01.20
#,# Double 1234567890 1,234,567,890
#,, Double 1234567890 1235
#,,, Double 1234567890 1
#,# #0, Double 1234567890 1,235
#0. ##% Double 0.086 8.6%
0.## #E +0 Double 86000 8.6E+4
0.## #E +000 Double 86000 8.6E+004
0.## #E -000 Double 86000 8.6E004
[##-##-##] Double 123456 [12-34-56]
# #;(# #) Double 1234 1234
# #;(# #) Double-1234 (1234)