iOS开发·NSDate日期基本操作方法
一、基本操作方法
1. 当前时间创建NSDate
NSDate *myDate = [NSDate date];
NSLog(@"myDate = %@",myDate);2. 从现在开始的24小时
NSTimeInterval secondsPerDay = 24*60*60;
NSDate *tomorrow = [NSDate dateWithTimeIntervalSinceNow:secondsPerDay];
NSLog(@"myDate = %@",tomorrow);3. 根据已有日期创建日期
NSTimeInterval secondsPerDay1 = 24*60*60;
NSDate *now = [NSDate date];
NSDate *yesterDay = [now addTimeInterval:-secondsPerDay1];
NSLog(@"yesterDay = %@",yesterDay);4. 比较日期
BOOL sameDate = [now isEqualToDate:yesterDay];
NSLog(@"sameDate = %lu",sameDate);5. 获取较早的日期
NSDate *earlierDate = [yesterDay earlierDate:now];
NSLog(@"earlierDate = %@",earlierDate);6. 获取较晚的日期
NSDate *laterDate = [yesterDay laterDate:now];
NSLog(@"laterDate = %@",laterDate);7. 两个日期之间相隔多少秒
NSTimeInterval secondsBetweenDates= [yesterDay timeIntervalSinceDate:now];
NSLog(@"secondsBetweenDates= %lf",secondsBetweenDates);8. 通过NSCalendar类来创建日期
NSDateComponents *comp = [[NSDateComponentsalloc]init];
[comp setMonth:06];
[comp setDay:01];
[comp setYear:2001];
NSCalendar *myCal = [[NSCalendaralloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *myDate1 = [myCal dateFromComponents:comp];
NSLog(@"myDate1 = %@",myDate1);9. 从已有日期获取日期
unsigned units = NSMonthCalendarUnit|NSDayCalendarUnit|NSYearCalendarUnit;
NSDateComponents *comp1 = [myCal components:units fromDate:now];
NSInteger month = [comp1 month];
NSInteger year = [comp1 year];
NSInteger day = [comp1 day]; 10. NSDateFormatter实现日期的输出
NSDateFormatter *formatter = [[NSDateFormatteralloc]init];
[formatter setDateStyle:NSDateFormatterFullStyle];//直接输出的话是机器码
//或者是手动设置样式[formatter setDateFormat:@"yyyy-mm-dd"];
NSString *string = [formatter stringFromDate:now];
NSLog(@"string = %@",string);
NSLog(@"formater = %@",formatter); 11. 获取日期格式对象
- (NSDateFormatter *)dateFormatter {
if (dateFormatter == nil) {
dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
}
return dateFormatter;
}二、日期比较操作
1. 方法调用
//获取被比较的指定日期
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd-MM-yyyy-HHmmss"];
NSDate *date = [dateFormatter dateFromString:@"30-09-2016-000000"];
//调用
[self compareOneDay:[self getCurrentTime] withAnotherDay:date] 2. 方法实现
#pragma mark -得到当前时间
- (NSDate *)getCurrentTime{
NSDateFormatter *formatter=[[NSDateFormatter alloc]init];
[formatter setDateFormat:@"dd-MM-yyyy-HHmmss"];
NSString *dateTime=[formatter stringFromDate:[NSDate date]];
NSDate *date = [formatter dateFromString:dateTime];
NSLog(@"---------- currentDate == %@",date);
return date;
}
- (int)compareOneDay:(NSDate *)oneDay withAnotherDay:(NSDate *)anotherDay
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd-MM-yyyy-HHmmss"];
NSString *oneDayStr = [dateFormatter stringFromDate:oneDay];
NSString *anotherDayStr = [dateFormatter stringFromDate:anotherDay];
NSDate *dateA = [dateFormatter dateFromString:oneDayStr];
NSDate *dateB = [dateFormatter dateFromString:anotherDayStr];
NSComparisonResult result = [dateA compare:dateB];
NSLog(@"date1 : %@, date2 : %@", oneDay, anotherDay);
if (result == NSOrderedDescending) {
//NSLog(@"Date1 is in the future");
return 1;
}
else if (result == NSOrderedAscending){
//NSLog(@"Date1 is in the past");
return -1;
}
//NSLog(@"Both dates are the same");
return 0;
} 拓展文献
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