iOS開發日記46-倒計時效果的實現,ios日記46-倒計時
今天博主有一個倒計時效果的實現的需求,遇到了一些困痛點,在此和大家分享,希望能夠共同進步.
首先在需要用到的地方解析總的倒計時時間,博主沒有封裝,各位看官可以自行封裝
#pragma mark--------新修改,增加倒計時
NSString *stringOfTime=[NSString stringWithFormat:@"%@",d[@"shipping_time"]];
double endUnixTime = [stringOfTime doubleValue];
// NSLog(@"++++++%.2f",endUnixTime);
NSCalendar *cal = [NSCalendar currentCalendar];
unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDate *date1 = [NSDate date];
NSDate *date2 = [NSDate dateWithTimeIntervalSince1970:endUnixTime];
NSDateComponents *dOfd = [cal components:unitFlags fromDate:date1 toDate:date2 options:0];
NSInteger sec = [dOfd hour]*3600+[dOfd minute]*60+[dOfd second];
//sec是總分鐘數
// NSLog(@"**********%@",dOfd);
UILabel *labelOfTime=(UILabel *)[_scroll viewWithTag:6954321];
if (sec>0) {
[self setCountDownWithTotalSec:sec withLabel:labelOfTime];
}
然後使用GCD實現倒計時功能
- (void)setCountDownWithTotalSec:(NSInteger)totalSec withLabel:(UILabel *)timeLbl{
__block NSInteger timeout = totalSec; //倒計時時間
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒執行
dispatch_source_set_event_handler(_timer, ^{
if(timeout<=0){ //倒計時結束,關閉
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//設定介面的按鈕顯示 根據自己需求設定
timeLbl.text = @"00:00:00";
});
}else{
long hours = timeout / 3600;
long minutes = (timeout - hours * 3600) / 60;
int seconds = timeout % 60;
NSString *strTime = [NSString stringWithFormat:@"%.2ld%.2ld%.2d",hours,minutes, seconds];
NSString *firstH = [strTime substringWithRange:NSMakeRange(0, 1)];
NSString *secondH = [strTime substringWithRange:NSMakeRange(1, 1)];
NSString *firstM = [strTime substringWithRange:NSMakeRange(2, 1)];
NSString *secondM = [strTime substringWithRange:NSMakeRange(3, 1)];
NSString *firstS = [strTime substringWithRange:NSMakeRange(4, 1)];
NSString *secondS = [strTime substringWithRange:NSMakeRange(5, 1)];
NSString *newTimeString = [NSString stringWithFormat:@"%@%@:%@%@:%@%@",firstH,secondH,firstM,secondM,firstS,secondS];
dispatch_async(dispatch_get_main_queue(), ^{
timeLbl.text = newTimeString;//回到主線程顯示
});
timeout--;
}
});
dispatch_resume(_timer);
}