标签: nsdate

假设我想要删除存储在NSString变量中的值,我将为其分配一个值nil.这个有可能.但是,如果我想删除已经包含某些值的日期变量,我该怎么办？

我想创建一个直到日期的天数倒计时.我对几小时或几分钟不感兴趣,只是从当前日期到设定日期的天数.这就是我一直在尝试的:

    NSDate *date = [NSDate date];
NSString *dateString = [date description];
// this **dateString** string will have **"yyyy-MM-dd HH:mm:ss +0530"**
//  NSMutableString *mutString = dateString;
NSArray *arr = [dateString componentSeperatedByString:@" "];
// arr will have [0] -> yyyy-MM-dd, [1] -> HH:mm:ss, [2] -> +0530 (time zone)

但它不起作用,因为当前日期是以分钟和秒为单位的时间.

//NSDate *currentDate = [[NSDate alloc] init];
NSString *start = [arr objectAtIndex:0];//[NSString stringWithFormat:@"%@", currentDate];//@"2011-11-05";
NSLog(@"%@",start);
NSString *end = @"2011-6-03";

NSDateFormatter *f = [[NSDateFormatter alloc] init];
[f setDateFormat:@"yyyy-MM-dd"];
NSDate *startDate = [f dateFromString:start];
NSDate *endDate …

这是我的代码

"时间间隔"= 1372418789000;

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd hh:mm:ss"];
NSDate *date = [NSDate dateWithTimeIntervalSince1970:1372418789000];
NSString *formattedDateString = [dateFormatter stringFromDate:date];
NSLog(@"formattedDateString: %@", formattedDateString);

输出格式为DateString:45460-03-21 10:53:20

但我要求的输出是2013-06-28 04:26:29 America/Los_Angeles

我在IBAction中有以下代码.我想测量AVSpeechSynthesizer在一系列方向上运行所花费的确切时间.但是,executionTime会立即记录而不是在循环结束时记录(返回不到一秒,而不是我预期的10-15秒).我做错了什么？

NSDate *methodStart = [NSDate date];

for (NSString* direction in directions) {

    AVSpeechUtterance *aDirection = [[AVSpeechUtterance alloc] initWithString:direction];
    aDirection.rate = .3;
    [self.synthesizer speakUtterance:aDirection];
}

NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];
NSLog(@"executionTime = %f", executionTime);

我有一个像这样的NSDateFormatter:

YYYY/MM/dd HH:mm:ss

我可以从转换NSDate到NSString和NSString到NSDate.但我想要的是在格式化时获取NSDate.我想把它转换成NSString然后转换回来,NSDate但这种方式很可怕,我确信有一种更简单的方法,对吧？

我有一个NSString格式的日期:"Jun 25, 2014 10:10:15 AM"

我需要把这个日期从一个NSDate.但我在日期格式上尝试了一些格式,并且NSDate设备上的值始终为nil.如果我在设备上或在模拟器上运行Xcode它的工作,但我生成.ipa并发送到iPhone无法正常工作.

码:

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"MMM dd, yyyy HH:mm:ss a"];
NSDate * dataStringFormatted = [dateFormat dateFromString: @"Jun 25, 2014 10:10:15 AM"];

我试过格式:

@"MMM dd, yyyy HH:mm:ss a"
@"MMM dd, yyyy H:mm:ss a"
@"MMM dd, yyyy HH:mm:ss aa"
@"MMM dd, yyyy H:mm:ss aa"
@"MMM dd, yyyy HH:mm:ss aaa"
@"MMM dd, yyyy H:mm:ss aaa"
@"MMMM dd, yyyy H:mm:ss aa"
@"MMMM dd, yyyy H:mm:ss aaa"
@"MMMM dd, …

我想以X年Y个月Z天的形式计算年龄.这是我的代码

 NSString *dateString = @"15-Sep-1997";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"dd-MMM-yyyy"];

NSDate *PrevDate = [dateFormatter dateFromString:dateString];


NSDate *today = [NSDate date];
NSLog(@"Prev date = %@", PrevDate);
NSLog(@"today =%@", today);
NSInteger  years;
NSInteger months;
NSInteger days;

NSCalendar *calendar = [NSCalendar currentCalendar];
unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents *dateComponentsNow = [calendar components:unitFlags fromDate:today];
NSDateComponents *dateComponentsBirth = [calendar components:unitFlags fromDate:PrevDate];

if (([dateComponentsNow month] < [dateComponentsBirth month]) ||
    (([dateComponentsNow month] == [dateComponentsBirth month]) && ([dateComponentsNow day] < [dateComponentsBirth day]))) { …

我想检测系统设置中完成的时间格式更改.我使用下面的代码,但它总是给我时间旧的格式.我怎样才能获得新的时间格式？

#pragma mark
#pragma mark - application change time format
-(void)applicationSignificantTimeChange:(UIApplication *)application
{
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setLocale:[NSLocale currentLocale]];
    [formatter setDateStyle:NSDateFormatterNoStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    [formatter setTimeZone:[NSTimeZone localTimeZone]];
    NSString *dateString = [formatter stringFromDate:[NSDate date]];
    NSLog(@"dataString ::%@",dateString);
    NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]];
    NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]];
    is12Hour = (amRange.length > 0 || pmRange.length > 0);
}

我正在尝试使用以下代码初始化NSTimeInterval:

NSTimeInterval *timeStamp = [[NSDate date] timeIntervalSince1970];

但它不断抛出错误:

使用不兼容类型'NSTimeInterval'(又名'double')的表达式初始化'NSTimeInterval*'(又名'double*')

我该如何解决？

我有CoreDatamyDate = date,Entity列并返回输出:

let mydate = coreDataValues[0].myDate!
print(mydate)

OUTPUT == 2017-02-01 12:45:40 +0000 

我想转换mydate成datetime下面的例子;

2017-12-20-23-59-59

我该怎么做 ？

泰