ios-时间换算

经常会遇到时间转换的，在此收藏一个时间换算的方法〜

 #pragma mark 时间换算

 + (NSString *)setcreateTime:(NSString *)str
 {
     //yyyy-MM-dd- HH:MMss"];

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

     //[formatter setDateStyle:NSDateFormatterMediumStyle];

     //[formatter setTimeStyle:NSDateFormatterShortStyle];

     [formatter setDateFormat:@"yyyy"];

     [formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"CCT"]];

     NSDate *date = [NSDate dateWithTimeIntervalSince1970:[str doubleValue]];

     NSString *dateStr = [formatter stringFromDate:date];

     //本地时间
     NSDate * senddate=[NSDate date];
     NSDateFormatter * dateformatter=[[NSDateFormatter alloc] init];
     [dateformatter setDateFormat:@"YYYY"];
     NSString * locationString=[dateformatter stringFromDate:senddate];

     //[dateformatter setDateFormat:@"YYYY-MM-dd-HH-mm-ss"];

     //判断创建时间 与 本地时间 是否同一年
     if ([dateStr isEqualToString:locationString]) {
         [formatter setDateFormat:@"MM-dd HH:mm"];
     }else{
         [formatter setDateFormat:@"yyyy-MM-dd HH:mm"];
     }

     date = [NSDate dateWithTimeIntervalSince1970:[str doubleValue]];
     dateStr = [formatter stringFromDate:date];

     return [self compareCurrentTime:date :dateStr];
 }

 + (NSString *) compareCurrentTime:(NSDate*) compareDate :(NSString *)str
 {
     NSTimeInterval  timeInterval = [compareDate timeIntervalSinceNow];
     timeInterval = -timeInterval;
     long temp = ;
     NSString *result;
     if (timeInterval < ) {
         if (timeInterval > ) {
             result = [NSString stringWithFormat:@"%d秒前",(int)timeInterval+];
         }else if (timeInterval < -){
             result = str;
         }
         else{
             result = [NSString stringWithFormat:@"%d秒前",];
         }

     }
     else if((temp = timeInterval/) <){
         result = [NSString stringWithFormat:@"%ld分钟前",temp];
     }else{
         result = str;
     }

     return  result;
 }