IOS学习笔记之十七

发布时间：2023-03-27 11:12:56 所属栏目：教程来源：

导读：IOS学习笔记之十七
1、NSDate时间与日期的初始化,主要有[NSDate date];2、NSDateFormatter主要用于NSString和Date之间相互转化//NSDate转NSStringstringFromDate:dt//NSString转NSDatedateFromString3、NSCalendar和

IOS学习笔记之十七
1、NSDate时间与日期的初始化,主要有[NSDate date];2、NSDateFormatter主要用于NSString和Date之间相互转化//NSDate转NSStringstringFromDate:dt//NSString转NSDatedateFromString3、NSCalendar和NSDateComponentsDate打印出具体时间的年月日和把年月日转化为Da...

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1、NSDate
时间与日期的初始化,主要有

[NSDate date];

2、NSDateFormatter

主要用于Nsstring和Date之间相互转化
//NSDate转Nsstring
stringFromDate:dt
//Nsstring转NSDate
dateFromString

3、NSCalendar和NSDateComponents
Date打印出具体时间的年月日和把年月日转化为Date

4、NSTimer
定时器
+ (NSTimer *)timerWithTimeInterval:(NSTimeInterval)ti invocation:(NSInvocation *)invocation repeats:(BOOL)yesOrNo;
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti invocation:(NSInvocation *)invocation repeats:(BOOL)yesOrNo;
+ (NSTimer *)timerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector userInfo:(nullable id)userInfo repeats:(BOOL)yesOrNo;
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector userInfo:(nullable id)userInfo repeats:(BOOL)yesOrNo;

5、测试Demo
main.m文件

int main(int argc,char * argv[]) {
@autoreleasepool {
//NSDate常用方法
NSDate *date = [NSDate date];
NSLog(@"%@",date);
NSDate *date1 = [[NSDate alloc] initWithTimeIntervalSinceNow:3600 * 24];
NSLog(@"date1 is %@",date1);
NSDate *date2 = [[NSDate alloc] initWithTimeIntervalSinceNow:-3 * 3600 * 24];
NSLog(@"date1 is %@",date2);
NSLocale *cn = [NSLocale currentLocale];
NSLog(@"%@",[date1 descriptionWithLocale:cn]);
NSLog(@"%@",[date1 earlierDate:date2]);

//NSDate转Nsstring
NSDate *dt = [NSDate dateWithTimeIntervalSince1970:3600 * 24 * 366 * 20];
NSDate *dt1 = [NSDate dateWithTimeIntervalSince1970:0];
NSLog(@"%@",dt1);
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"公元yyyy年MM月DD日 HH时mm分"];
NSLog(@"%@",[df stringFromDate:dt]);
//Nsstring转NSDate

Nsstring *str = @"2018-03-02";
NSDateFormatter *df1 = [[NSDateFormatter alloc] init];
[df1 setDateFormat:@"yyyy-MM-dd"];
NSLog(@"%@",[df1 dateFromString:str]);

//NSCalendar和NSDateComponents使用
NSCalendar *car = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *date3 = [NSDate date];
unsigned unit = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSWeekdayCalendarUnit;

NSDateComponents *comp = [car components:unit fromDate:date3];
NSLog(@"现在是%ld年",comp.year);
NSLog(@"现在是%ld月",comp.month);
NSLog(@"现在是%ld日",comp.day);
NSLog(@"现在是%ld时",comp.hour);
NSLog(@"现在是%ld分",comp.minute);
NSLog(@"现在是%ld秒",comp.second);
NSLog(@"现在是星期%ld",comp.weekday);

NSDateComponents *comp1 = [[NSDateComponents alloc] init];
comp1.year = 2015;
comp1.month = 4;
comp1.day = 5;
comp1.hour = 18;
comp1.minute = 34;
NSDate *date4 = [car dateFromComponents:comp1];
NSLog(@"date is %@:",date4);
return UIApplicationMain(argc,argv,nil,NsstringFromClass([AppDelegate class]));
}
}

ViewControl.m文件(这里实现的定时器)

@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Control *control = [Control new];
// control.delegate = self;
// [control willShowAlert];
NSTimer* timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(Timered:) userInfo:nil repeats:YES];
}
- (void)Timered:(NSTimer*)timer {
NSLog(@"hello chenyu");
}
@end

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