检测时间格式是否为12小时或24小时格式

Question

有没有什么方法可以检测到应用的当前设备是否使用12小时我们的24h格式，这样我可以使用一个NSDateFormatter 12小时和一个24小时，具体取决于用户的语言/放置设置？就像UIDatePicker检测并显示AM/PM选取器是否为12h格式一样。

Answer 1

我觉得它很容易。我只是说此代码viewDidLoad：

NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
[formatter setLocale:[NSLocale currentLocale]]; 
[formatter setDateStyle:NSDateFormatterNoStyle]; 
[formatter setTimeStyle:NSDateFormatterShortStyle]; 
NSString *dateString = [formatter stringFromDate:[NSDate date]]; 
NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]]; 
NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]]; 
BOOL is24h = (amRange.location == NSNotFound && pmRange.location == NSNotFound); 
[formatter release]; 
NSLog(@"%@\n",(is24h ? @"YES" : @"NO")); 

而且它完美地返回YES或NO取决于语言环境。

Answer 2

这里是斯威夫特版本：

func using12hClockFormat() -> Bool { 

    let formatter = NSDateFormatter() 
    formatter.locale = NSLocale.currentLocale() 
    formatter.dateStyle = NSDateFormatterStyle.NoStyle 
    formatter.timeStyle = NSDateFormatterStyle.ShortStyle 

    let dateString = formatter.stringFromDate(NSDate()) 
    let amRange = dateString.rangeOfString(formatter.AMSymbol) 
    let pmRange = dateString.rangeOfString(formatter.PMSymbol) 

    return !(pmRange == nil && amRange == nil) 
} 

Answer 3

这里是一个雨燕3.0更新版本

func using12hClockFormat() -> Bool { 

    let formatter = DateFormatter() 
    formatter.locale = Locale.current 
    formatter.dateStyle = .none 
    formatter.timeStyle = .short 

    let dateString = formatter.string(from: Date()) 
    let amRange = dateString.range(of: formatter.amSymbol) 
    let pmRange = dateString.range(of: formatter.pmSymbol) 

    return !(pmRange == nil && amRange == nil) 
} 

Answer 4

这是为我工作迅速解决，以上这两个没有。

let dateString : String = DateFormatter.dateFormat(fromTemplate: "j", options: 0, locale: Locale.current)!
 

if(dateString.contains("a")){ 
    // 12 h format 
     return true 
    }else{ 
    // 24 h format 
     return false 
    } 

Answer 5

目标C类NSDate+Extensions：

@import Foundation; 

@interface NSDate (Extensions) 

- (NSString *)getTimeString; 

@end 


#import "NSDate+Extensions.h" 

@implementation NSDate (Extensions) 

- (NSString *)getTimeString 
{ 
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
    if ([self isTwelveHourDateFormat]) { 
     [formatter setDateFormat:@"hh:mm\ndd MMM"]; 
    } 
    else { 
     [formatter setDateFormat:@"HH:mm\ndd MMM"]; 
    } 
    return [formatter stringFromDate:self]; 
} 

- (BOOL)isTwelveHourDateFormat 
{ 
    NSString *dateFormat = [NSDateFormatter dateFormatFromTemplate:@"j" options:0 locale:[NSLocale currentLocale]]; 
    return [dateFormat containsString:@"a"]; 
} 

@end