将 DatePicker 日期转换为 UTC 格式 returns NULL

Question

我有 4 个 UITextfiled，开始日期、开始时间和结束日期、结束时间。然后我将我的日期和时间发送到我的 UTC 函数，但它返回 null。

NSString *str1 = _startDateField.text;
str1 = [str1 stringByAppendingString:@" "];
str1 = [str1 stringByAppendingString:_startTimeField.text];
NSLog(@"str1 : %@", str1);
NSString *str2 = _endDateField.text;
str2 = [str2 stringByAppendingString:@" "];
str2 = [str2 stringByAppendingString:_endTimeField.text];
NSLog(@"str2 : %@", str2);
// Convert string to date object
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd-MMM-yyyy HH:mm"];
NSDate *date1 = [dateFormat dateFromString:str1];
NSDate *date2 = [dateFormat dateFromString:str2];
NSLog(@"%@", date1);
NSLog(@"%@", date2);
NSString *startTime = [self getUTCFormateDate:date1];
NSString *endTime = [self getUTCFormateDate:date2];
NSLog(@"str1 : %@", startTime);
NSLog(@"str2 : %@", endTime);

转换为UTC格式：

-(NSString *)getUTCFormateDate:(NSDate *)localDate {
    NSLog(@"%@", localDate);
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
    [dateFormatter setTimeZone:timeZone];
    [dateFormatter setDateFormat:@"dd-MMM-yyyy HH:mm"];
    NSString *dateString = [dateFormatter stringFromDate:localDate];
    NSLog(@"%@", dateString);
    return dateString;
}

我想从我的文本字段中读取日期和时间并将它们转换为 UTC 格式。

Answer 1

你的代码很好而且正确，我添加了 defaultTimeZone 来获取时区并将时间减去 utc 时间。我得到了输出。

检查这个

NSString *str1 = @"26-Nov-2019";
str1 = [str1 stringByAppendingString:@" "];
str1 = [str1 stringByAppendingString:@"9:35 am"];
NSLog(@"str1 : %@", str1);
NSString *str2 = @"26-Nov-2019";
str2 = [str2 stringByAppendingString:@" "];
str2 = [str2 stringByAppendingString:@"11:59"];
NSLog(@"str2 : %@", str2);

// Convert string to date object
NSDate *date1 = [self getUTCDate:str1];
NSDate *date2 = [self getUTCDate:str2];

NSLog(@"date1 %@", date1);
NSLog(@"date2 %@", date2);

NSString *startTime = [self getUTCFormateDate:date1];
NSString *endTime = [self getUTCFormateDate:date2];
NSLog(@"str1 : %@", startTime);
NSLog(@"str2 : %@", endTime);


-(NSDate *)getUTCDate:(NSString *)currentDate {
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"dd-MMM-yyyy HH:mm"];

    NSDate *date1 = [dateFormat dateFromString:currentDate];
    if (date1 == nil) {
         [dateFormat setDateFormat:@"dd-MMM-yyyy hh:mm a"];
         date1 = [dateFormat dateFromString:currentDate];
    }
    return date1;
}

-(NSString *)getUTCFormateDate:(NSDate *)localDate {
    NSLog(@"%@", localDate);
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
    [dateFormatter setTimeZone:timeZone];
    [dateFormatter setDateFormat:@"dd-MMM-yyyy HH:mm"];
    NSLocale *twelveHourLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    dateFormatter.locale = twelveHourLocale;
    NSTimeInterval timeZoneoffset = [[NSTimeZone defaultTimeZone] secondsFromGMT];
    NSTimeInterval utcTimeInterval = [localDate timeIntervalSinceReferenceDate] - timeZoneoffset;
    NSDate *utcCurrentDate = [NSDate dateWithTimeIntervalSinceReferenceDate:utcTimeInterval];
    NSString *dateString = [dateFormatter stringFromDate:utcCurrentDate];
    NSLog(@"dateString %@", dateString);
    return dateString;
}

将 DatePicker 日期转换为 UTC 格式 returns NULL

Converting DatePicker Date to UTC Format returns NULL

xcode

cocoa-touch

objective-c

nsdateformatter

ios