NSDate 的一些操作（比较、创建、在现有date加减一定时间等）-白红宇

NSDate 的一些操作（比较、创建、在现有date加减一定时间等）

阅读量：6123 次

发布时间：2019-06-21

本文共 1895 字，大约阅读时间需要 6 分钟。

创建当前

[cpp]

NSDate *date = [NSDate date];

从现在开始的24小时

NSTimeterval a_day = 24*60*60;

NSDate *tomorrow = [NSDate dateWithTimeIntervalSinceNow:a_day];

根据已有日期创建日期

[cpp]

NSTimeInterval a_day = 24*60*60;

NSDate *date = [NSDate date];

NSDate *tomorrow = [date addTimeInterval: date];

日期比较

[cpp]

BOOL isEqual = [date isEqualToDate:tomorrow];

f(isEqual){

NSLog(@"equal");

//较早的日期

[cpp]

NSDate *earlier_date = [tomorrow earlierDate:date];

NSLog(@"earlierDate = %@",earlierDate);

//较晚的日期

[cpp]

NSDate *laterDate = [tomorrow laterDate:date];

NSLog(@"laterDate = %@",laterDate);

//两个日期之间相隔多少秒

[cpp]

NSTimeInterval secondsInterval= [date timeIntervalSinceDate:tomorrow];

NSLog(@"secondsInterval= %lf",secondsInterval);

//通过NSCalendar类来创建日期

[cpp]

NSDateComponents *comps = [[NSDateComponentsalloc]init];

[comps setMonth:01];

[comps setDay:31];

[comps setYear:2013];

NSCalendar *calendar = [[NSCalendaralloc]initWithCalendarIdentifier:NSGregorianCalendar];

NSDate *date = [calendar dateFromComponents:comps];

//从已有日期获取日期

[cpp]

unsigned units = NSMonthCalendarUnit|NSDayCalendarUnit|NSYearCalendarUnit;

NSDateComponents *_comps = [calendar components:units fromDate:date];

NSInteger month = [_comps month];

NSInteger year = [_comps year];

NSInteger day = [_comps day];

//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 *dateString = [formatter stringFromDate:date];

NSLog(@"dateString = %@",dateString);

NSLog(@"formater = %@",formatter);

//获取日期格式对象

[cpp]

1. - (NSDateFormatter *)getDateFormatter {
2. if (dateFormatter == nil) {
3. dateFormatter = [[NSDateFormatter alloc] init];
4. [dateFormatter setDateStyle:NSDateFormatterMediumStyle];
5. [dateFormatter setTimeStyle:NSDateFormatterNoStyle];
6. }
7. return dateFormatter;
8. }