Conversion between NSDate, NSString, and timestamp in iOS development, nsdatensstring

Conversion between NSDate, NSString, and timestamp in iOS development, nsdatensstring

1 // convert UTCDate (the World Standard Time) to the standard Date of the local time zone (the time displayed by the clock) 2 // NSDate * date = [NSDate date Date]; 06:54:41 + 0000 3 // After conversion: 14:54:41 + 0000 4-(NSDate *) getLocalDateFromUTCDate :( NSDate *) UTCDate {5 6 NSTimeZone * tz = [NSTimeZone ultulttimezone]; 7 NSInteger seconds = [tz secondsFromGMTForDate: UTCDate]; 8 return [NSDate dateWithTimeInterval: seconds sinceDate: UTCDate]; 9 10} 11 12 // convert the standard Date of the local time zone to UTCDate 13 // the current standard time of the local area: 14:54:41 + 0000 14 // convert it to the world standard time: 06:54:41 + 0000 15-(NSDate *) Expiration :( NSDate *) LocalDate {16 17 NSTimeZone * tz = [NSTimeZone defaultTimeZone]; 18 NSInteger seconds =-[tz secondsFromGMTForDate: LocalDate]; 19 return [NSDate dateWithTimeInterval: seconds sinceDate: LocalDate]; 20 21} 22 23 // obtain the current time String Based on UTCDate (time displayed on the clock) 24 // input: [NSDate date] 07:44:05 + 0000 25 // output: 15:44:05 26-(NSString *) localStringFromUTCDate :( NSDate *) UTCDate {27 28 NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init]; 29 NSTimeZone * tz = [NSTimeZone defaultTimeZone]; 30 [dateFormatter setTimeZone: tz]; 31 [dateFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss"]; 32 NSString * result = [dateFormatter stringFromDate: UTCDate]; 33 return result; 34 35} 36 37 // obtain the current time string (time displayed on the clock) based on the UTC string 38 // input: 07:44:05 39 // output: 15:44:05 40-(NSString *) localStringFromUTCString :( NSString *) UTCString {41 42 // convert the UTC string to UTCDate first; 43 NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init]; 44 NSTimeZone * tz = [NSTimeZone timeZoneWithAbbreviation: @ "GMT"]; 45 [dateFormatter setTimeZone: tz]; 46 [dateFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss "]; 47 NSDate * UTCDate = [dateFormatter dateFromString: UTCString]; 48 49 [dateFormatter setTimeZone: [NSTimeZone defaultTimeZone]; 50 NSString * result = [dateFormatter stringFromDate: UTCDate]; 51 return result; 52} 53 54 // convert the current time string to UTCDate 55-(NSDate *) UTCDateFromLocalString :( NSString *) localString {56 57 NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init]; 58 [dateFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss"]; 59 NSDate * date = [dateFormatter dateFromString: localString]; 60 return date; 61} 62 63 // convert the current time string to the UTC string 64-(NSString *) UTCStringFromLocalString :( NSString *) localString {65 66 NSDate * date = [self UTCDateFromLocalString: localString]; 67 NSString * string = [NSString stringWithFormat: @ "% @", date]; 68 NSString * result = [string substringToIndex: string. length-6]; 69 return result; 70 71} 72 73 // UTCDate to UTC string 74-(NSString *) UTCStringFromUTCDate :( NSDate *) UTCDate {75 76 NSDateFormatter * dataFormatter = [[NSDateFormatter alloc] init]; 77 [dataFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss"]; 78 NSTimeZone * tz = [NSTimeZone timeZoneWithAbbreviation: @ "GMT"]; 79 [dataFormatter setTimeZone: tz]; 80 NSString * UTCString = [dataFormatter stringFromDate: UTCDate]; 81 return UTCString; 82 83} 84 85 // convert the current time (UTCDate) to the timeStampFromUTCDate (NSDate *) UTCDate {87 88 NSTimeInterval timeInterval = [UTCDate timeIntervalSince1970]; 89 // * 1000, accurate to milliseconds; precise to seconds; 90 NSString * result = [NSString stringWithFormat: @ "%. 0f ", timeInterval]; 91 return result; 92 93} 94 95 // convert the current time string (time displayed on the clock) to the time stamp 96-(NSString *) timeStamapFromLocalString :( NSString *) localString {97 98 // convert it to UTCDate 99 NSDate * UTCDate = [self UTCDateFromLocalString: localString]; 100 NSString * timeStamap = [self accept: UTCDate]; 101 return timeStamap; 102 103} 104 105 // convert UTCString to timeStamapFromUTCString (NSString *) UTCString {106 107 // convert the UTC string to UTCDate first; 109 NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init]; 110 NSTimeZone * tz = [NSTimeZone timeZoneWithAbbreviation: @ "GMT"]; 111 [dateFormatter setTimeZone: tz]; 112 [dateFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss"]; 113 NSDate * UTCDate = [dateFormatter dateFromString: UTCString]; 114 115 NSString * timeStamap = [self timeStampFromUTCDate: UTCDate]; 116 return timeStamap; 117} 118 119 // time stamp to UTCDate120-(NSDate *) UTCDateFromTimeStamap :( NSString *) timeStamap {121 122 NSTimeInterval timeInterval = [timeStamap doubleValue]; 123 // 1000; if the input timeStamap is accurate to milliseconds, remember to/1000124 NSDate * UTCDate = [NSDate dateWithTimeIntervalSince1970: timeInterval]; 125 return UTCDate; 126 127}

If you want to convert the timestamp into a string, convert it based on the obtained UTCDate.