如何从 NSDate 变量获取工作日和/或月份名称？

Question

好吧。我们遇到的问题是 NSString 填充了日期 格式为 yyyyMMdd，我们想要做的是获取当前工作日和月份名称。函数 dagOmvandlare 将日期字符串转换为工作日和月份。然后在 viewDidload 上调用该函数来命名我们所有的按钮标题，从英语到瑞典语月份。

我们当前的解决方案如下所示：

-(NSString *)dagOmvandlare:(id) suprDatum{

   NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
   dateFormatter.dateFormat = @"yyyyMMdd";

   NSDate *date = [dateFormatter dateFromString:suprDatum];


   NSString * monthString = [date descriptionWithCalendarFormat:@"%B"timeZone:nil
                                                         locale:[[NSUserDefaults standardUserDefaults] dictionaryRepresentation]];

   if ([monthString isEqualToString:@"January"]) {
       monthString = @"Januari";
   }
   else
       if ([monthString isEqualToString:@"February"]) {
           monthString = @"Februari";
       }
       else
           if ([monthString isEqualToString:@"May"]) {
               monthString = @"Maj";
           }
           else
               if ([monthString isEqualToString:@"June"]) {
                   monthString = @"Juni";
               }
               else
                   if ([monthString isEqualToString:@"July"]) {
                       monthString = @"Juli";
                   }
                   else
                       if ([monthString isEqualToString:@"August"]) {
                           monthString = @"Augusti";
                       }
                       else
                           if ([monthString isEqualToString:@"October"]) {
                               monthString = @"Oktober";
                           }
                           else
                               if ([monthString isEqualToString:@"March"]) {
                                   monthString = @"Mars";
                               }

   return monthString;

}



- (void)viewDidLoad {
   [super viewDidLoad];

    [button3 setTitle:(NSString *)[self dagOmvandlare:self.datum1] forState:UIControlStateNormal];
    [button2 setTitle:(NSString *)[self dagOmvandlare:self.datum2] forState:UIControlStateNormal];
    [bmanad1 setTitle:(NSString *)[self dagOmvandlare:self.datum3] forState:UIControlStateNormal];

}

到目前为止，我们发现

NSString * monthString = [date descriptionWithCalendarFormat:@"%B"timeZone:nil
                                                         locale:[[NSUserDefaults standardUserDefaults] dictionaryRepresentation]];

苹果公司关于非公共 api 的指南不允许使用 。所以主要问题是，还有什么其他方法可以从包含 yyyyMMdd 格式的日期的日期字符串中获取工作日和月份名称？

Answer 1

无需手动转换为瑞典语单词。 iPhone 会为你做这件事。试试这个：

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"yyyyMMdd";
NSDate *date = [dateFormatter dateFromString:@"20111010"];

// set swedish locale
dateFormatter.locale=[[NSLocale alloc] initWithLocaleIdentifier:@"sv_SE"];

dateFormatter.dateFormat=@"MMMM";
NSString *monthString = [[dateFormatter stringFromDate:date] capitalizedString];
NSLog(@"month: %@", monthString);

dateFormatter.dateFormat=@"EEEE";
NSString *dayString = [[dateFormatter stringFromDate:date] capitalizedString];
NSLog(@"day: %@", dayString);

输出：

month: Oktober
day: Måndag

Answer 2

简单的 Swift 3 扩展：

// Weekday
extension Date {
    func dayOfWeek() -> String? {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "EEEE"
        return dateFormatter.string(from: self).capitalized
        // or capitalized(with: locale)
    }
}

print(Date().dayOfWeek()!) // Wednesday

// Month Name
extension Date {
    func monthName() -> String? {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "MMMM"
        return dateFormatter.string(from: self).capitalized
        // or capitalized(with: locale)
    }
}

print(Date().monthName()!) // October

Answer 3

NSString *strDate=@"20110407";
NSDateFormatter *df=[[[NSDateFormatter alloc] init] autorelease];
[df setDateFormat:@"yyyyMMdd"];
NSDate *targetDate=[df dateFromString:strDate];
[df setDateFormat:@"EEEE MMMM dd, yyyy"];
NSString *s=[df stringFromDate:targetDate];

NSLog(@"Date: %@", s);

Answer 4

希望这会有所帮助

NSCalendar *calendar= [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDate *date = [NSDate date];
NSDateComponents *dateComponents = [calendar components:unitFlags fromDate:date];

NSInteger year = [dateComponents year];
NSInteger month = [dateComponents month];
NSInteger day = [dateComponents day];
NSInteger hour = [dateComponents hour];
NSInteger minute = [dateComponents minute];
NSInteger second = [dateComponents second];

[calendar release];

这可能有用

另一个SO问题可能会帮助你如何使用 NSDate 从今天的日期查找工作日？

Answer 5

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"EEEE"];
NSString *dayName = [dateFormatter stringFromDate:Date];

this dayName 将在用户的区域设置中可用。

Answer 6

正如苹果所说，创建（并让 ARC 处理）格式化程序的成本很高，因此：

1）在文件中声明：

private var localDateFormatter : DateFormatter?

..
extension Date {

2）使用惰性方法：

if localDateFormatter == nil{

        localDateFormatter = DateFormatter()

        let locale = Locale(identifier: "en_US_POSIX")

....}
    let newTime = localDateFormatter!.date(from: self)

如果您在一个类中拥有所有内容，那么 static / let 成员会很好。 （我们不能在扩展中使用变量...:(全局变量似乎很糟糕，但没办法...）

Answer 7

您可以使用（对于 Swift 和 Türkiye 本地化）：

dateFormatter.locale = NSLocale(localeIdentifier: "tr_TR") as Locale

Answer 8

- (void) getMonthFromDate:(NSString *) stringDate
{
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    NSDate *date = [dateFormat dateFromString:stringDate];
    NSCalendar* calendar = [NSCalendar currentCalendar];
    NSDateComponents* components = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:date]; // Get necessary date components

    NSLog(@"%lu", [components day]);
    NSLog(@"%lu %@",[components day],[[dateFormat monthSymbols] objectAtIndex:[components month]]);

}