一.单例定时器
二.倒计时
1.自定义label
//GPLTimeLab.h
@interface GPLTimeLab : UILabel
/// 根据传入的时间计算和当前时间的进行比较，开始倒计时
- (void)setupCountDownWithTargetTime:(NSDate *)targetTime;
/// 根据传入的具体秒数，开始倒计时
- (void)beginCountDownWithTimeInterval:(NSTimeInterval)timerInterval;
/// 根据传入的两个时间差，开始倒计时
- (void)beginCountDownFromTime:(NSDate *)fromDate toTime:(NSDate *)toDate;
@end
@interface GPLTimeLab ()
/// 定时器，使用 weak 或者 strong 都行
@property (nonatomic, strong) NSTimer *timer;
/// 剩余天数
@property (nonatomic, assign) NSUInteger day;
/// 剩余小时数
@property (nonatomic, assign) NSUInteger hour;
/// 剩余分钟数
@property (nonatomic, assign) NSUInteger minute;
/// 剩余秒数
@property (nonatomic, assign) NSUInteger second;
@end
@implementation GPLTimeLab
/// 根据传入的时间计算和当前时间的进行比较，开始倒计时
- (void)setupCountDownWithTargetTime:(NSDate *)targetTime {
// 计算传入的时间和当前的时间差
NSTimeInterval interval = [targetTime timeIntervalSinceDate:[NSDate date]];
[self initTimeParametersWithTimeInterval:(NSInteger)interval];
}
/// 根据传入的具体秒数，开始倒计时
- (void)beginCountDownWithTimeInterval:(NSTimeInterval)timerInterval {
[self initTimeParametersWithTimeInterval:timerInterval];
}
/// 根据传入的两个时间差，开始倒计时
- (void)beginCountDownFromTime:(NSDate *)fromDate toTime:(NSDate *)toDate {
NSTimeInterval interval = [fromDate timeIntervalSinceDate:toDate];
NSLog(@"%f",interval);
if (interval<0) {
NSLog(@"已完成");
self.text = @"已完成";
} else {
[self initTimeParametersWithTimeInterval:interval];
}
}
/// 通过传入的时间间隔对时间参数进行初始化
- (void)initTimeParametersWithTimeInterval:(NSInteger)interval {
NSUInteger secondPerDay = 24 * 60 * 60;
NSUInteger secondPerHour = 60 * 60;
NSUInteger secondPerMinute = 60;
// 计算天数
self.day = interval / secondPerDay;
// 剩余小时不应该大于24小时，所以应该先除去满足一天的秒数，再计算还剩下多少小时
self.hour = interval % secondPerDay / secondPerHour;
// 剩余分钟数与上面同理
self.minute = interval % secondPerHour / secondPerMinute;
// 剩余秒数直接等于秒数对每分钟秒数所取的余数
self.second = interval % secondPerMinute;
// 更新值
[self updateText];
self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}
/// 时间减一秒方法
- (void)updateTimer {
// 减一秒
self.second--;
// 判断秒数
if (self.second == -1) {
self.second = 59;
self.minute--;
}
// 判断分钟数
if (self.minute == -1) {
self.minute = 59;
self.hour--;
}
// 判断小时数
if (self.hour == -1) {
self.hour = 23;
self.day--;
}
// 判断是否没时间了
if (self.day == 0 && self.hour == 0 && self.minute == 0 && self.second == 0) {
[self.timer invalidate];
self.text = @"已完成";
self.timer = nil;
[self removeFromSuperview];
}
[self updateText];
NSLog(@"%s", __func__);
}
- (void)updateText {
if (self.day == 0 && self.hour == 0 && self.minute == 0 && self.second == 0)
{
self.text = @"已完成";
[self removeFromSuperview];
}
else
{
self.text = [NSString stringWithFormat:@"倒计时：%02zd 天 %02zd:%02zd:%02zd", self.day, self.hour, self.minute, self.second];
}
}
// best solution
- (void)removeFromSuperview {
[super removeFromSuperview];
[self.timer invalidate];
}
// this solution don't work....
// - (void)dealloc {
//
// [self.timer invalidate];
// }
@end
使用时,每次进入页面从后台获取当前时间和到期时间
//1、 获得到期时间串
NSString *timSts = [NSString stringWithFormat:@"%@",[dataDic objectForKey:@"end_time"]];
NSLog(@"到期时间是:%@",timSts);
//获取当前时间串
nowDateStr = [NSString stringWithFormat:@"%@",[dataDic objectForKey:@"current_time"]];
NSLog(@"当前时间是22:%@",nowDateStr);
[gpltimelab beginCountDownFromTime:[self creatDaoDate:timSts] toTime:[self creatDaoDate:nowDateStr]];
//字符串转时间
-(NSDate *)creatDaoDate:(NSString *)Str
{
NSTimeZone *sourceTimeZone = [NSTimeZone timeZoneWithName:@"Asia/Shanghai"];
NSDateFormatter *format = [[NSDateFormatter alloc] init];
format.dateFormat = @"YYYY-MM-dd HH:mm:ss";
format.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"];
format.timeZone = sourceTimeZone;
NSDate *date = [format dateFromString:Str];
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate:date];
NSDate *localDate = [date dateByAddingTimeInterval:interval];
NSLog (@"date is : %@", localDate );
return localDate;
}