Question

添加评论后，我需要在标签上显示评论时间，如前一年前，前一天，前几分钟和前一秒，但它会返回-4425，-33434秒前＆＃34;随机数＆＃34;。

以下是我在我的应用中使用的代码。

NSString *inDateStr = [NSString stringWithFormat:@"%@",[[[dict objectForKey:@"d"] objectAtIndex:indexPath.row-1] objectForKey:@"created"]];
NSString *s = @"yyyy-MM-dd HH:mm:ss";

// about input date(GMT)
NSDateFormatter *inDateFormatter = [[NSDateFormatter alloc] init];
inDateFormatter.dateFormat = s;
inDateFormatter.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT-7.00"];
NSDate *inDate = [inDateFormatter dateFromString:inDateStr];

// about output date(IST)
NSDateFormatter *outDateFormatter = [[NSDateFormatter alloc] init];
outDateFormatter.timeZone = [NSTimeZone localTimeZone];
outDateFormatter.dateFormat = s;
NSString *outDateStr = [outDateFormatter stringFromDate:inDate];

// final output
NSLog(@"[in]%@ -> [out]%@", inDateStr, outDateStr);

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *dateStartingString = [[NSDate alloc] init];
NSString *datestartString = outDateStr;

dateStartingString = [dateFormatter dateFromString:datestartString];

NSTimeInterval timeDifference = [[NSDate date] timeIntervalSinceDate:dateStartingString];



double minutes = timeDifference / 60;
double hours = minutes / 60;
double seconds = timeDifference;
double days = minutes / 1440;

UILabel * dateLbl=[[UILabel alloc] initWithFrame:CGRectMake(155, [[CountArr objectAtIndex:indexPath.row] floatValue]-1, 80, 20)];
if(seconds>=86400)
    dateLbl.text=[NSString stringWithFormat:@"%.0f days ", days];
else if(seconds>=3600 && seconds<86400 )
    dateLbl.text=[NSString stringWithFormat:@"%.0f hours ", hours];
else if (seconds>=60 && seconds<3600 )
    dateLbl.text=[NSString stringWithFormat:@"%.0f minutes ", minutes];
else
    dateLbl.text=[NSString stringWithFormat:@"%.0f seconds ", seconds];

dateLbl.textColor=[UIColor lightGrayColor];
dateLbl.font = [UIFont systemFontOfSize:12];
[cell.contentView addSubview:dateLbl];

Answer 1

我相信NSDateFormatter只接受一个字符串并返回一个NSDate对象。设置时区用于设置NSDate的属性，但实际上并不转换所提供的时间。所以最后如果你在格林威治标准时间5:30放入，你将获得5:30的IST。

您希望使用NSCalender进行时区转换。

Answer 2

您可以使用此方法来获得日期差异确保日期格式正确。如果你得到负值，只需检查日期格式。

-(NSDateComponents *)getDateDifference:(NSString *)date
{
    NSDate *dateA=[NSDate date]; //Current date
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd"];
    NSDate *dateB = [dateFormatter dateFromString:date];//Convert nsstring to nsdate


    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; //Gregorian allocation
    NSDateComponents *components = [calendar components:NSDayCalendarUnit|NSHourCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit
                                               fromDate:dateA
                                                 toDate:dateB
                                                options:0]; //Get day and hour

    return components;
}


// Call method like 
NSDateComponents *difference = [self getDateDifference:marriageDate];
NSLog(@"diff year = %f",difference.year);

NSTimeInterval显示不正确的时间间隔

2 个答案: