获取NSDate并在swift中将其从24小时格式转换为12小时格式

我看过其他语言的这篇文章，但没有看过斯威夫特的。我以

2015-08-31 21:36:00+0000的格式保存了一个日期，并且我能够使用下面的代码提取日期、月份、年份和工作日，以生成
2015年8月31日星期一
。当我尝试使用：

let hourInt = components.hour
var hourString = String(hourInt)

它打印出四个小时的差异。在本例中，“17”表示“21”。我该怎么办
将其显示为晚上9:36

let flags: NSCalendarUnit =  NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitHour |  NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitWeekday | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitYear
let date = NSDate()
let dateFormatter: NSDateFormatter = NSDateFormatter()
let components = NSCalendar.currentCalendar().components(flags, fromDate: array.date)


let weekday = components.weekday
let weekdays = dateFormatter.weekdaySymbols
let weekdayString = weekdays[weekday-1] as! String

let month = components.month
let months = dateFormatter.monthSymbols
let monthString = months[month-1] as! String

let dayInt = components.day
var dayString = String(dayInt)

let year = components.year
let yearString = String(year)
println(weekdayString + ", " + monthString + " " + dayString + ", " + yearString)

---

如果要删除时区信息，请传递GMT时区。 此代码与您的代码完全相同

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy"
dateFormatter.timeZone = NSTimeZone(abbreviation: "GMT")
println(dateFormatter.stringFromDate(array.date))

---

如果要删除时区信息，请传递GMT时区。 此代码与您的代码完全相同

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy"
dateFormatter.timeZone = NSTimeZone(abbreviation: "GMT")
println(dateFormatter.stringFromDate(array.date))

---

日期字符串后缀+0000表示它是UTC时间。如果要以UTC时间显示时间，则需要在设置日期格式化程序时指定它

let dateString = "2015-08-31 21:36:00 +0000"
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
if let date = df.dateFromString(dateString) {
    // now you have your date object
    // to display UTC time you have to specify timeZOne UTC
    df.timeZone = NSTimeZone(forSecondsFromGMT: 0)
    df.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
    let stringFromDate = df.stringFromDate(date)
    println(stringFromDate)   // "Monday, August 31, 2015 9:36:00 PM"
}

---

日期字符串后缀+0000表示它是UTC时间。如果要以UTC时间显示时间，则需要在设置日期格式化程序时指定它

let dateString = "2015-08-31 21:36:00 +0000"
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
if let date = df.dateFromString(dateString) {
    // now you have your date object
    // to display UTC time you have to specify timeZOne UTC
    df.timeZone = NSTimeZone(forSecondsFromGMT: 0)
    df.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
    let stringFromDate = df.stringFromDate(date)
    println(stringFromDate)   // "Monday, August 31, 2015 9:36:00 PM"
}

---

将NSDateFormatter的区域设置设置为

en_US\u POSIX

修复了我的问题

let sharedFormatter:NSDateFormatter = {
    let formatter = NSDateFormatter()
    formatter.locale = NSLocale(localeIdentifier:"en_US_POSIX")
    return formatter
}()

sharedFormatter.dateFormat = "MMM d YYYY, h:mm a"
let dateString = sharedFormatter.stringFromDate(NSDate()) 
// Aug 2 2016, 5:45 PM

---

将NSDateFormatter的区域设置设置为

en_US\u POSIX

修复了我的问题

let sharedFormatter:NSDateFormatter = {
    let formatter = NSDateFormatter()
    formatter.locale = NSLocale(localeIdentifier:"en_US_POSIX")
    return formatter
}()

sharedFormatter.dateFormat = "MMM d YYYY, h:mm a"
let dateString = sharedFormatter.stringFromDate(NSDate()) 
// Aug 2 2016, 5:45 PM

---

Swift 5.0

let dateString = "2015-08-31 21:36:00 +0000"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"

if let date = dateFormatter.date(from: dateString) {
    // now you have your date object
    // to display UTC time you have to specify timeZOne UTC
    dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
    dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
    let stringFromDate = dateFormatter.string(from: date)
    print(stringFromDate)   // "Monday, August 31, 2015 9:36:00 PM"
}

---

Swift 5.0

let dateString = "2015-08-31 21:36:00 +0000"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"

if let date = dateFormatter.date(from: dateString) {
    // now you have your date object
    // to display UTC time you have to specify timeZOne UTC
    dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
    dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
    let stringFromDate = dateFormatter.string(from: date)
    print(stringFromDate)   // "Monday, August 31, 2015 9:36:00 PM"
}

---

使用NSDateFormatter，并记住设置时区。NSDates是绝对时间点，不知道时区。请参阅使用NSDateFormatter，并记住设置时区。NSDates是绝对时间点，不知道时区。看见