NSDate的處理：前一天、後一天等關於時區偏移的處理以及在資料庫中的使用
阿新 • • 發佈：2019-02-14
看來很多網上關於日期的處理，今天、昨天、前天、後天、一週等，滿心歡喜的拿著去驗證結果總是不盡如人意，看別別人的程式碼看的腦漲，自己就寫一個簡單的，自己來用，以後用其他的方法，我會在完善，再次記錄，以方便以後查閱
--宋飛祥 2014.7.19
直接上程式碼，很容易理解：
#import <Foundation/Foundation.h> @interface MyCutomNSDateDeal : NSObject +(NSInteger)timeZoneOffset; +(NSInteger)preDayOfTheDate_start:(NSDate *)date; +(NSInteger)preDayOfTheDate_end:(NSDate *)date; +(NSInteger)nextDayOfTheDate_start:(NSDate *)date; +(NSInteger)nextDayOfTheDate_end:(NSDate *)date; @end
#import "MyCutomNSDateDeal.h" @implementation MyCutomNSDateDeal +(NSInteger)timeZoneOffset { NSDate *date = [NSDate date]; NSTimeZone *zone = [NSTimeZone systemTimeZone]; NSInteger offset = [zone secondsFromGMTForDate:date]; return offset; } /** * 根據給出的日期，返回該日期的前一天的起點（相對於日期起點，seconds的計數） * * @param date 日期 * * @return 返回的是seconds計數，相對於日曆系統起始至該日期前一天的起點（就是0點） */ +(NSInteger)preDayOfTheDate_start:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]-24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } /** * 根據給出的日期，返回該日期的前一天的終點(也就是給出日期的起點） * * @param date 給定的日期 * * @return 返回的是seconds計數 */ +(NSInteger)preDayOfTheDate_end:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } +(NSInteger)nextDayOfTheDate_start:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]+24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } +(NSInteger)nextDayOfTheDate_end:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]+ 2*24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } //+(NSInteger)preWeekOfTheDate_ @end
使用如下：
這裡我取得date 為當天的，使用者可以換成自己想要的相對日期即可！！
列印結果如下：NSDate *today = [NSDate date]; NSLog(@"today ::::: %@",today); NSInteger today_int = [MyCutomNSDateDeal preDayOfTheDate_start:today]; NSDate *per_start = [NSDate dateWithTimeIntervalSince1970:today_int]; NSLog(@"per_start _:_ %@",per_start); NSDate *per_end = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal preDayOfTheDate_end:today]]; NSLog(@"per_end -:- %@",per_end); NSDate *next_start = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal nextDayOfTheDate_start:today]]; NSDate *next_end = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal nextDayOfTheDate_end:today]]; NSLog(@"next_start === %@",next_start); NSLog(@"next_end === %@",next_end);
2014-07-19 <span style="color:#FF0000;">15:26:30.565 </span>FMDBSortByDateDemo[4423:60b] today ::::: 2014-07-19 <span style="color:#FF0000;">07:26:30</span> +0000
2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] per_start _:_ 2014-07-18 00:00:00 +0000
2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] per_end -:- 2014-07-19 00:00:00 +0000
2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] next_start === 2014-07-20 00:00:00 +0000
2014-07-19 15:26:30.567 FMDBSortByDateDemo[4423:60b] next_end === 2014-07-21 00:00:00 +0000這裡我想說的是：我專案中用到要存資料和date，而資料庫（FMDB）是不支援date格式的，我採取的是把相對日曆起點的seconds（秒）存起來，通過比對秒數來取想要的資料！
如果大家有好的方法，可以交流！！
下面是我的資料庫取值過程：
NSInteger inter = [MyCutomNSDateDeal preDayOfTheDate_end:today];
NSString *sql = [NSString stringWithFormat:@"SELECT * FROM Temperature WHERE Date > %i ",inter];
// NSString *sql = [NSString stringWithFormat:@"SELECT * FROM Temperature WHERE Date between %li and %li",from,to];
if ([db open]) {
FMResultSet *rs = [db executeQuery:sql];
while ([rs next]) {
NSString *name = [rs stringForColumn:@"Name"];
NSInteger time = [rs intForColumn:@"Date"];
NSDate *date = [NSDate dateWithTimeIntervalSince1970:time];
float temp = [rs doubleForColumn:@"Temperature"];
NSString *event = [rs stringForColumn:@"Event"];
NSLog(@"Name:%@,Date:%@,Temperature:%f,Event:%@",name,date,temp,event);
}
}兩個sql語句都驗證了，是正確的，有一點我要說的是，我們在處理取出的資料時，加上了偏移量，所以我們存取資料時，也要加上偏移量，應該如下：
-(void)temperatureAndDateUpdate:(float)value
{
NSDate *date = [NSDate date];
NSInteger time = [date timeIntervalSince1970];
time = time + [MyCutomNSDateDeal timeZoneOffset]; //加上時區偏移量
NSDate *date1 = [NSDate dateWithTimeIntervalSince1970:time];
NSLog(@"temperature update date1 === %@",date1);
if ([db open]) {
[db executeUpdate:@"INSERT INTO Temperature(Name,Date,Temperature,Event) VALUES (?,?,?,?)",@"SFX",[NSNumber numberWithInteger:time],[NSNumber numberWithFloat:value],@"吃藥"];
NSLog(@"success!!");
}else
{
NSLog(@"error: %@ %@",[db lastError],[db lastErrorMessage]);
}
[db close];
}