1、两种方法
1 传统方法
NSDate *nowDate = [NSDate date]; // 当前日期
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd HH-mm-ss";
NSDate *creat = [formatter dateFromString:(任意时间)];// 将传入的字符串转化成时间
NSTimeInterval delta = [nowDate timeIntervalSinceDate:creat]; // 计算出相差多少秒
//打印结果格式为 delta ==== 181078.541819
2 便捷方法
NSDate *nowDate = [NSDate date]; // 当前时间
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd HH-mm-ss";
NSDate *creat = [formatter dateFromString:creat_time]; // 传入的时间
// 这里有个需要注意的地方，不要将时间戳的字符串直接作为creat_time ，如果是时间戳，那么
NSString *timeString = @"1532754000"; // 时间戳字符串
NSTimeInterval time=[timeString doubleValue]/1000;//传入的时间戳str如果是精确到毫秒的记得要/1000 (注意： 这句话不要全盘复制，如果传入的时间戳没有精确到毫秒不要除1000)
NSDate *creat =[NSDate dateWithTimeIntervalSince1970:time];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSCalendarUnit unit = NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
NSDateComponents *compas = [calendar components:unit fromDate:creat toDate:nowDate options:0];
NSLog(@"year=%zd month=%zd day=%zd hour=%zd minute=%zd",compas.year,compas.month,compas.day,compas.hour,compas.minute);
2.封装一些简单实用的方法，NSDate的分类
import "NSDate+Extension.h"
#import <Foundation/Foundation.h>
@interface NSDate (Extension)
/**
*传入时间与当前时间的差值
*/
- (NSDateComponents *)deltaFrom:(NSDate *)date;
/**
*是否为今年
*/
- (BOOL)isThisYear;
/**
*是否为今天
*/
- (BOOL)isToday;
/**
*是否为昨天
*/
- (BOOL)isYestoday;
/**
*返回只有年月日的时间
*/
- (NSDate *)dateWithYMD;
import "NSDate+Extension.m"
#import "NSDate+Extension.h"
@implementation NSDate (Extension)
- (NSDateComponents *)deltaFrom:(NSDate *)date{
NSCalendar *calendar = [NSCalendar currentCalendar];
NSCalendarUnit unit = NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
NSDateComponents *compas = [calendar components:unit fromDate:self toDate:date options:0];
return compas;
}
- (BOOL)isThisYear{
// 日历
NSCalendar *calendar = [NSCalendar currentCalendar];
NSInteger nowYear = [calendar component:NSCalendarUnitYear fromDate:[NSDate date]];
NSInteger selfYear = [calendar component:NSCalendarUnitYear fromDate:self];
return nowYear == selfYear;
}
// 第一种方法
//- (BOOL)isToday{
// // 日历
// NSCalendar *calendar = [NSCalendar currentCalendar];
// NSCalendarUnit unit = NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear;
// NSDateComponents *nowComp = [calendar components:unit fromDate:[NSDate date]];
// NSDateComponents *selfComp = [calendar components:unit fromDate:self];
// return nowComp.year == selfComp.year
// && nowComp.month == selfComp.month
// && nowComp.day == selfComp.day;
//}
// 第二种方法
- (BOOL)isToday{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd";
NSString *nowString = [formatter stringFromDate:[NSDate date]];
NSString *selfString = [formatter stringFromDate:self];
return nowString == selfString;
}
- (BOOL)isYestoday{
NSDate *nowDate = [[NSDate date] dateWithYMD];
NSDate *selfDate = [self dateWithYMD];
// 获得nowDate和selfDate的差距、
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *cmps = [calendar components:NSCalendarUnitDay fromDate:selfDate toDate:nowDate options:0];
return cmps.day == 1;
}
- (NSDate *)dateWithYMD{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd";
NSString *selfString = [formatter stringFromDate:self];
return [formatter dateFromString:selfString];
}
@end
