NSTimeInterval顯示不正確的時間間隔

Question

添加評論後，我需要顯示與一年前，一天前，幾分鐘前和第二次前的標籤上的評論時間，但它會返回-4425，-33434秒前的「隨機數」。

這是我在下面顯示的代碼在我的應用程序中使用。

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只接受一個字符串並返回一個NSDate對象。設置時區是爲了設置NSDate的屬性，但並不實際轉換所提供的時間。所以最後如果你在格林威治標準時間5點30分，你會得到5點30分的IST。

您會改爲使用NSCalender來進行時區轉換。

Answer 2

您可以使用此方法獲取日期差異。
確保日期格式正確。如果您收到負值，請檢查日期格式。

-(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);