我怎么能得到本地时区在ios

Question

我需要根据ios设备的位置设置本地时区。

[dateFormat setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]]; 

或

[dateFormat setTimeZone:[NSTimeZone timeZoneWithName:@"GTC+5.30"]]; 

适合吗?

Answer 1

// get current date/time
NSDate *today = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
// display in 12HR/24HR (i.e. 11:25PM or 23:25) format according to User Settings
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
NSString *currentTime = [dateFormatter stringFromDate:today];
[dateFormatter release];
NSLog(@"User's current time in their preference format:%@",currentTime);

您可以使用以下命令获取本地时区名称:

NSTimeZone *timeZone = [NSTimeZone localTimeZone];
NSString *tzName = [timeZone name];

Answer 2

我是这样做的:

    NSString *strDateFormat = @"yyyy-MM-dd'T'HH:mm:ss.SSS";
    // ---------------------------------------------------------
    // input date is UTC date time, need to convert that time
    // to user's own local device timezone to get correct date
    // ---------------------------------------------------------
    NSDateFormatter *dateFormatterUTC = [[NSDateFormatter alloc] init];
    [dateFormatterUTC setDateFormat:strDateFormat];
    [dateFormatterUTC setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
    // get UTC Date first
    NSDate* utcDate = [dateFormatterUTC dateFromString:strDate];
    // get local date from UTC Date
    NSDateFormatter *dateFormatterLocal = [[NSDateFormatter alloc] init];
    [dateFormatterLocal setDateFormat:strDateFormat];
    [dateFormatterLocal setTimeZone:[NSTimeZone systemTimeZone]];
    // get final local date calculated by offsetting UTC Date
    NSDate *localDate = [dateFormatterUTC dateFromString:[dateFormatterLocal stringFromDate:utcDate]];
    NSDate *localNowDate = [dateFormatterUTC dateFromString:[dateFormatterLocal stringFromDate:[NSDate date]]];

Answer 3

NSString *dateStr = @"2012-07-16 07:33:01";
NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc] init]; 
[dateFormatter1 setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; 
NSDate *date = [dateFormatter1 dateFromString:dateStr];
NSLog(@"date : %@",date);
NSTimeZone *currentTimeZone = [NSTimeZone localTimeZone];
NSTimeZone *utcTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
NSInteger currentGMTOffset = [currentTimeZone secondsFromGMTForDate:date];
NSInteger gmtOffset = [utcTimeZone secondsFromGMTForDate:date];
NSTimeInterval gmtInterval = currentGMTOffset - gmtOffset;
NSDate *destinationDate = [[[NSDate alloc] initWithTimeInterval:gmtInterval sinceDate:date] autorelease];
NSDateFormatter *dateFormatters = [[NSDateFormatter alloc] init];
[dateFormatters setDateFormat:@"dd-MMM-yyyy hh:mm"];
[dateFormatters setDateStyle:NSDateFormatterShortStyle];
[dateFormatters setTimeStyle:NSDateFormatterShortStyle];
[dateFormatters setDoesRelativeDateFormatting:YES];
[dateFormatters setTimeZone:[NSTimeZone systemTimeZone]];  
dateStr = [dateFormatters stringFromDate: destinationDate];
NSLog(@"DateString : %@", dateStr);
- (Courtesy: Yuvaraj.M)

Answer 4

您可以使用NSTimeZone类的localTimeZone类方法来获取一个相对时区对象，该对象将自身解码为其所在地区的默认时区。

SRC: https://developer.apple.com/library/mac/documentation/cocoa/reference/foundation/classes/NSTimeZone_Class/Reference/Reference.html//apple_ref occ/clm/NSTimeZone/localTimeZone

如果需要纬度和经度:从http://www.iana.org/time-zones获取官方时区数据库。下载tzdata2013g.tar.gz。存档里有个文件叫zone。选项卡，为每个时区提供时间/长度，例如:

 CH      +4723+00832     Europe/Zurich

+4723+00832表示纬度= +47º23"，经度= +8º23"(SRC:从iPhone获取时区/国家)