我如何从NSDate获得小时和分钟？

在我的应用程序中，我需要分别获取小时和分钟：

NSString *currentHour=[string1 substringWithRange: NSMakeRange(0,2)];
        int currentHourInNumber=[currentHour intValue];

考虑string1包含11:59:13 AM来自日期选择器的内容。

在这里，如果我使用上面的代码，则大于9 NSMakeRange(0,1)可以获取小时。否则，我需要更改以获取1到9之间的小时。

是否有获取小时，分钟等的方法？

在此先感谢您提供示例代码。

使用NSDateFormatter转换string1为NSDate，然后获取所需的NSDateComponents：

Obj-C：

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"<your date format goes here"];
NSDate *date = [dateFormatter dateFromString:string1];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitHour | NSCalendarUnitMinute) fromDate:date];
NSInteger hour = [components hour];
NSInteger minute = [components minute];

迅捷1和2：

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "Your date Format"
let date = dateFormatter.dateFromString(string1)
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Hour, .Minute], fromDate: date)
let hour = comp.hour
let minute = comp.minute

迅捷3：

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "Your date Format"
let date = dateFormatter.date(from: string1)
let calendar = Calendar.current
let comp = calendar.dateComponents([.hour, .minute], from: date)
let hour = comp.hour
let minute = comp.minute

有关dateformat的更多信息位于官方unicode网站上

如果只需要它以字符串形式显示，则下面的代码会容易得多

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"HH:mm"];

NSString *startTimeString = [formatter stringFromDate:startTimePicker.date];

在我看来，这就是所要解决的问题，不需要格式化程序：

NSDate *date = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitHour | NSCalendarUnitMinute) fromDate:date];
NSInteger hour = [components hour];
NSInteger minute = [components minute];

NSDateComponents

您需要的所有信息都可以在这里找到：https :
//developer.apple.com/library/content/documentation/Cocoa/Conceptual/DatesAndTimes/Articles/dtCalendars.html

如果要使用C库，则可以这样做：

time_t t;
struct tm * timeinfo;

time (&t);
timeinfo = localtime (&t);

NSLog(@"Hour: %d Minutes: %d", timeinfo->tm_hour, timeinfo->tm_min);

并使用Swift：

var t = time_t()
time(&t)
let x = localtime(&t)

println("Hour: \(x.memory.tm_hour) Minutes: \(x.memory.tm_min)")

有关更多指导，请参见：http : //www.cplusplus.com/reference/ctime/localtime/

与iOS 8，苹果推出了一个辅助方法来检索hour，minute，second和nanosecond从一个NSDate对象。

目标C

NSDate *date = [NSDate currentDate];
NSInteger hour = 0;
NSInteger minute = 0;
NSCalendar *currentCalendar = [NSCalendar currentCalendar];
[currentCalendar getHour:&hour minute:&minute second:NULL nanosecond:NULL fromDate:date];
NSLog(@"the hour is %ld and minute is %ld", (long)hour, (long)minute);

迅速

let date = NSDate()
var hour = 0
var minute = 0
let calendar = NSCalendar.currentCalendar()
if #available(iOS 8.0, *) {
    calendar.getHour(&hour, minute: &minute, second: nil, nanosecond: nil, fromDate: date)
    print("the hour is \(hour) and minute is \(minute)")
}

雨燕2.0

您可以执行以下操作从日期获取小时和分钟：

let dateFromat = NSDateFormatter()
dateFromat.dateFormat = "hh:mm a"
let date = dateFromat.dateFromString(string1) // In your case its string1
print(date) // you will get - 11:59 AM

雨燕2.0

    let dateNow = NSDate()
    let calendar = NSCalendar.currentCalendar()
    let hour = calendar.component(NSCalendarUnit.Hour, fromDate: dateNow)
    let minute = calendar.component(NSCalendarUnit.Minute, fromDate: dateNow)
    print(String(hour))
    print(String(minute))

请注意打印语句中对String的强制转换，您可以轻松地将该值分配给变量，如下所示：

var hoursString = String(hour)
var minutesString = String(minute)

然后，您可以将值串联起来：

var compoundString = "\(hour):\(minute)"
print(compoundString)