我编写了将当前时间转换为 utc-gmt 或 gmt -utc 的函数。如果 msgArrivedDate 为空，这些函数就可以正常工作。如果不是(这意味着 msgArrivedDate 来自不转换的休息服务。

jSON 解析部分:

NSArray *messageSentTime = [[args valueForKey:@"messageSendDate"] objectAtIndex:0];

    for(int i=0 ;i< [messageSentTime count]; i++)
    {
        //[self timeZoneFormatter:@"GMT" :[messageSentTime objectAtIndex:i]];

        NSLog(@"Converted time = %@",[self timeZoneFormatter:@"GMT" :[messageSentTime objectAtIndex:i]]);

函数部分:

-(id)timeZoneFormatter:(NSString *)formatType : (NSString *)msgArrivedDate
{
    NSDate *date;

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];


    if([msgArrivedDate length] > 0)
    {

        date = [dateFormatter dateFromString:msgArrivedDate];

    } else {

        date = [NSDate date];
    }


    if([formatType isEqualToString:@"UTC"])
    {
        [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];

    }

    if([formatType isEqualToString:@"GMT"])
    {
        [dateFormatter setTimeZone:[NSTimeZone localTimeZone]];

    }

    NSString *dateString = [dateFormatter stringFromDate:date];

    return dateString;
}

ReST 以 UTC 格式返回这些值:

"2013-09-24 15:03:17",
"2013-09-25 12:09:22",
"2013-09-25 13:07:45",
"2013-09-25 13:08:19",
"2013-09-25 14:22:38"

当我调用该函数时，(NSLog(@"Converted time = %@",[self timeZoneFormatter:@"GMT":[messageSentTime objectAtIndex:i]])) 返回:

 messageSentTime = (
    "2013-09-24 15:03:17",
    "2013-09-25 12:09:22",
    "2013-09-25 13:07:45",
    "2013-09-25 13:08:19",
    "2013-09-25 14:22:38" )

我想我只是遗漏了这里的小问题 :( 还找不到......

最佳答案

改变这个:

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

为此:

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];

编辑:此方法将处理日期字符串从 UTC 到 GMT 以及从 GMT 到 UTC 的转换:

- (id)translateDate:(NSString *)msgArrivedDate
               from:(NSString *)fromTimeZone
                 to:(NSString *)toTimeZone {
    NSDate *date = nil;
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

    if([fromTimeZone isEqualToString:@"UTC"]) {
        [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
    }

    if([fromTimeZone isEqualToString:@"GMT"]) {
        [dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
    }

    if([msgArrivedDate length] > 0) {
        date = [dateFormatter dateFromString:msgArrivedDate];
    } else {
        date = [NSDate date];
    }

    if([toTimeZone isEqualToString:@"UTC"]) {
        [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
    }

    if([toTimeZone isEqualToString:@"GMT"]) {
        [dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
    }

    NSString *dateString = [dateFormatter stringFromDate:date];
    return dateString;
}

将“2013-09-25 14:22:38”从 UTC 转换为 GMT(即本地时间，在您使用的 GMT 中)将导致 2013-09-25 15:22:38，同样，将“2013-09-25 14:22:38”从 GMT 转换为 UTC 将导致 2013-09-25 13:22:38。

关于ios - GMT 和 UTC 格式器与 NSDateFormatter，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19024092/