String. Format exception "incorrect input string Format" SOLUTION

1. Escape

C # uses placeholders such as {0}, {1: yyyy-MM-dd}. What if the formatted string itself contains {or? The answer is: Use two {or} hyphens to represent a single one.

For example
StringStr1 = String. Format ("{Hello}, {0}, Now is {1: yyyy-MM-dd HH: mm: ss }}}",
"Jinglecat",
DateTime. Now );// {Hello}, Jinglecat, Now is {23:06:35}
StringStr2 = String. Format ("{Hello}, {0}, Now is {1: yyyy-MM-dd HH: mm: ss }}",
"Jinglecat",
DateTime. Now );// --> System. FormatException: the format of the input string is incorrect.

In fact, in many cases, characters with special meanings are escaped like this: for example,
In C #, when the String constant carries @ leading, two "hyphens are used to represent a" (half-width double quotation marks)
StringStr3 =@ "My UserName is" "Jinglecat "".";// My UserName is "Jinglecat ".
// String str4 = @ "My username's" jinglecat ""; // error cs1002: should be input;
// String str5 = @ "My username's \" jinglecat \ ""; // error cs1002: it should be input;

SQL string constant, expressed by two 'concatenation '(single quotation marks)
Declare @ Str6 Varchar(100)
Set @ Str6='My username is''Jinglecat''.'
Print @ Str6 -- My username is 'jinglecat '.

In a regular expression, two $ connections represent one $ (dollar)

Ii. String formatting in C #

The basic content is:Console. writeline(AndString. Format, It isConsole. writelineCall. The complete format is as follows:

{Index[,Width] [:Formatstring]}

Where,IndexIt is a parameter after the format string referenced by the formatting program, which starts from scratch;Width(If any) is to set the width of the format field (in space ).WidthPositive number indicates the right alignment of the result. negative number indicates the left alignment of the number in the field. (See the first two examples below .)

FormatstringIs optional. It contains the format description for setting the Type format. If the object is implementedIformattable,FormatstringWill be passed to the objectFormatMethod (in Beta 2 and later versions, the signature of this method is changedTostring (string, iformatprovider)). If the object is not implementedIformattableWill callObject. ToString ()While ignoringFormatstring.

Note that the current language is not differentiated in Beta 1.ToStringIn Beta 2 and later versions, "differentiate" languages. For example, for countries separated by "." and separated by ",", 1,234.56 will be formatted as 1.234, 56. UseCultureInfo. InvariantCultureAs a language.

To obtain complete information about the format, see the format Overview In the. NET Framework developer guide ).

Example: String. format ("[{0,-10:0 ##. #0}] ", 14) =" [014.00] ";-10 indicates left alignment, which occupies 10 digits in total and is not empty enough.

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 ("-> {} <-", "Hello ");	-> Hello <-
String. Format ("-> {1,-10} <-", "Hello ");	-> Hello <-

Numbers

Basic number formatting specifiers:

Specifier	Type	Format	Output (Passed dual 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	-1.2420.e + 004
F	Fixed point	{0: f}	1.42	-12400.00
G	General	{0: g}	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: x4}	System. FormatException	Cf90

Note: {0: n2} indicates the use of thousands of places to separate the two following novel points.

Custom number formatting:

Specifier	Type	Example	Output (Passed dual 1500.42)	Note
0	Zero placeholder	{. 0000}	1500.4200	Pads with zeroes.
#	Digit placeholder	{0 :(#).##}	(1500). 42
.	Decimal point	{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	Specified 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 currency formatting example at the bottom of this document makes it obvious:

Note:

If the number is a leading zero or trailing zero, the "#" character is replaced with a null value. The "0" character is replaced with zero characters regardless of the value of the corresponding number-therefore, the number is replaced with zero. The period (if any) indicates the position of the decimal separator.

So why should we use these letters at the same time, such as "### 0 .##"? If you want to set the format value to exactly zero, the "#" image character will be replaced with "NONE" (or even zero character ). You may "always" expect at least "0" to the left of the decimal point. Otherwise, if the value is zero, the field will not be output. In other words, only the "#" character is contained. A "0" format is often considered a programming error.

For example

String. Format ("{0: #####}, 14") = "14 ";

String. Format ("{0: 0 ##. #0}, 14") = "014.00"

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 10,200 2
T	Short Time	10: 11 pm
T	Long time	10:11:29
F	Full date & time	December 10,200 2 PM
F	Full date & time (long)	December 10,200 2 10:11:29
G	Default date & time	10/12/2002 PM
G	Default date & time (long)	10/12/2002 10:11:29
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 11,200 2 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	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
/	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 :( ###) #######}", 8005551212 );

This will output "(800) 555-1212 ″.