iOS Development--nsdateformatter

The NSDate object contains two parts, date, and time. The formatted time string is mainly for the date and time

1. Basic usage

1nsdate* now =[NSDate Date];2nsdateformatter* FMT =[[NSDateFormatter alloc] init];3Fmt.datestyle =Kcfdateformattershortstyle;4Fmt.timestyle =Kcfdateformattershortstyle;5Fmt.locale = [[Nslocale alloc] Initwithlocaleidentifier:@"en_US"];6nsstring* datestring =[FMT Stringfromdate:now];7NSLog (@"%@", datestring);

Print output: 10/29/12, 2:27 PM
This uses the system to provide a formatted string, which is set through fmt.datestyle and fmt.timestyle . The parameters used in the instance are Kcfdateformattershortstyle, plus:

1typedef cf_enum (Cfindex, Cfdateformatterstyle) {//date and time format styles2Kcfdateformatternostyle =0,//No output3Kcfdateformattershortstyle =1,//10/29/12, 2:27 PM4Kcfdateformattermediumstyle =2,//Oct, 2:36:59 PM5Kcfdateformatterlongstyle =3,//October, 2:38:46 PM gmt+08:006Kcfdateformatterfullstyle =4      //Monday, October, 2:39:56 PM China7};

2. Customizing the regional language
As in the example above, we are using the regional language is en_US, which refers to American English. If we switch to Simplified Chinese, the code is:

1 fmt.locale = [[Nslocale alloc] Initwithlocaleidentifier:@ "zh_cn"];

Then the corresponding output is:

1typedef cf_enum (Cfindex, Cfdateformatterstyle) {//date and time format styles2Kcfdateformatternostyle =0,//No output3Kcfdateformattershortstyle =1,//12-10-29 pm 2:524Kcfdateformattermediumstyle =2,//2012-10-29 pm 2:51:435Kcfdateformatterlongstyle =3,//October 29, 2012 gmt+0800 2:51 P.M. 08 sec6Kcfdateformatterfullstyle =4      //Monday, October 29, 2012, China Standard Time 2:46 P.M. 49 seconds7};

World-wide regional language code, see International for Unicode (ICU), Http://userguide.icu-project.org/formatparse/datetime

3. Custom date and time formats
NSDateFormatter provides a custom date-time method, mainly by setting the property DateFormat, which is commonly set as follows:

1nsdate* now =[NSDate Date];2nsdateformatter* FMT =[[NSDateFormatter alloc] init];3Fmt.locale = [[Nslocale alloc] Initwithlocaleidentifier:@"ZH_CN"];4Fmt.dateformat =@"yyyy-mm-dd ' T ' HH:mm:ss";5nsstring* datestring =[FMT Stringfromdate:now];6NSLog (@"%@", datestring);

Print output: 2012-10-29t16:08:40

In addition to the listed above, you can also specify a number of formats, see Http://userguide.icu-project.org/formatparse/datetime.
You can also print out localized string information in conjunction with locale settings.

1nsdate* now =[NSDate Date];2nsdateformatter* FMT =[[NSDateFormatter alloc] init];3Fmt.locale = [[Nslocale alloc] Initwithlocaleidentifier:@"ZH_CN"];4Fmt.dateformat =@"yyyy-mm-dd a HH:mm:ss eeee";5nsstring* datestring =[FMT Stringfromdate:now];6NSLog (@"\n%@", datestring);

Print output: 2012-10-29 16:25:27 Mon

4. Custom month week and other characters
NSDateFormatter also provides the appropriate way to modify these characters. In general, use the default character below the corresponding region language to be OK. But you do have the need, and you can do it. The corresponding method is very numerous, as follows:

Managing AM and PM Symbols

• –amsymbol
• –setamsymbol:
• –pmsymbol
• –setpmsymbol:

Managing Weekday Symbols

• –weekdaysymbols
• –setweekdaysymbols:
• –shortweekdaysymbols
• –setshortweekdaysymbols:
• –veryshortweekdaysymbols
• –setveryshortweekdaysymbols:
• –standaloneweekdaysymbols
• –setstandaloneweekdaysymbols:
• –shortstandaloneweekdaysymbols
• –setshortstandaloneweekdaysymbols:
• –veryshortstandaloneweekdaysymbols
• –setveryshortstandaloneweekdaysymbols:

Managing Month Symbols

• –monthsymbols
• –setmonthsymbols:
• –shortmonthsymbols
• –setshortmonthsymbols:
• –veryshortmonthsymbols
• –setveryshortmonthsymbols:
• –standalonemonthsymbols
• –setstandalonemonthsymbols:
• –shortstandalonemonthsymbols
• –setshortstandalonemonthsymbols:
• –veryshortstandalonemonthsymbols
• –setveryshortstandalonemonthsymbols:

Managing Quarter Symbols

• –quartersymbols
• –setquartersymbols:
• –shortquartersymbols
• –setshortquartersymbols:
• –standalonequartersymbols
• –setstandalonequartersymbols:
• –shortstandalonequartersymbols
• –setshortstandalonequartersymbols:

Managing Era Symbols

• –erasymbols
• –seterasymbols:
• –longerasymbols
• –setlongerasymbols:

Zz:http://www.cnblogs.com/xinus/archive/2012/10/29/nsdateformatter_samples.html

iOS Development--nsdateformatter