iOS:将 UTC 时区转换为设备本地时区

Question

我正在尝试将以下时区转换为设备本地时区:

2013-08-03T05:38:39.590Z

请告诉我如何将其转换为本地时区。

我该怎么做？

Answer 1

时区可以应用于 NSDateFormatter ，您可以从中生成按时差区分的 NSDate 变量。

NSString* input = @"2013-08-03T05:38:39.590Z";
NSString* format = @"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";

// Set up an NSDateFormatter for UTC time zone
NSDateFormatter* formatterUtc = [[NSDateFormatter alloc] init];
[formatterUtc setDateFormat:format];
[formatterUtc setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

// Cast the input string to NSDate
NSDate* utcDate = [formatterUtc dateFromString:input];

// Set up an NSDateFormatter for the device's local time zone
NSDateFormatter* formatterLocal = [[NSDateFormatter alloc] init];
[formatterLocal setDateFormat:format];
[formatterLocal setTimeZone:[NSTimeZone localTimeZone]];

// Create local NSDate with time zone difference
NSDate* localDate = [formatterUtc dateFromString:[formatterLocal stringFromDate:utcDate]];

NSLog(@"utc:   %@", utcDate);
NSLog(@"local: %@", localDate);

[formatterUtc release];
[formatterLocal release];