iOS将服务器时间转换为设备本地时间？

Question

我收到一些问题将服务器时间（阿根廷）转换为设备本地时间。 这里是我当前的代码 -

-(NSString *)getLocalTimeStringFrom:(NSString *)sourceTime 
{ 
    static NSDateFormatter* df = nil; 
    if (df == nil) 
    { 
     df = [[NSDateFormatter alloc]init]; 
    } 
    df.dateFormat = @"HH:mm:ss"; 

    NSDate* d = [df dateFromString:sourceTime]; 
    NSTimeZone *sourceZone = [NSTimeZone timeZoneWithAbbreviation:@"ART"];//America/Argentina/Buenos_Aires (GMT-3) 
    NSTimeZone *localTimeZone = [NSTimeZone systemTimeZone]; //Asia/Kolkata (IST) 

    [df setTimeZone: sourceZone]; 
    NSLog(@"sourceZone time is %@" , [df stringFromDate: d]); 
    [df setTimeZone: localTimeZone]; 
    NSLog(@"local time is %@" , [df stringFromDate: d]); 

    NSLog(@"original time string was %@" , sourceTime); 
    return [df stringFromDate: d]; 
} 

这里是日志如果sourceTime字符串00:05:00

2015-09-28 15:04:24.118 DeviceP[230:17733] sourceZone time is 15:35:00 
2015-09-28 15:04:24.121 DeviceP[230:17733] local time is 00:05:00 
2015-09-28 15:04:33.029 DeviceP[230:17733] original time string was 00:05:00 

请注意，我让本地时间相同时间字符串我传递给方法。我看起来像各种SO后this和this。 任何帮助，将不胜感激。

Answer 1

由于您的时间字符串在ART中，因此您应该在设置字符串日期之前设置日期格式化程序的时区。像下面这样的手段

-(NSString *)getLocalTimeStringFrom:(NSString *)sourceTime 
{ 
    static NSDateFormatter* df = nil; 
    if (!df) { 
     df = [[NSDateFormatter alloc]init]; 
     df.dateFormat = @"HH:mm:ss"; 
    } 

    NSTimeZone *sourceZone = [NSTimeZone timeZoneWithAbbreviation:@"ART"]; 
    [df setTimeZone: sourceZone]; 
    NSDate *ds = [df dateFromString:sourceTime]; 
    NSLog(@"sourceZone time is %@" , [df stringFromDate: ds]); 

    NSTimeZone *localTimeZone = [NSTimeZone systemTimeZone]; 
    [df setTimeZone: localTimeZone]; 
    NSLog(@"local time is %@" , [df stringFromDate: ds]); 

    return [df stringFromDate: d]; 
}