NSTimer減少秒/毫秒的時間

Question

我正在開發一個QuiZ應用程序。它需要一個倒數計時器，因爲我想在75：00.00（mm：ss.SS）啓動一個計時器，並通過減少1毫秒將其減少到00：00.00（mm：ss.SS）。我想顯示一個提醒，即時間！當時間到達00：00.00（mm：ss.SS）時。

我通過下面的鏈接

Stopwatch using NSTimer incorrectly includes paused time in display

Answer 1

這是一個簡單的解決方案，您的問題。

聲明

@interface ViewController : UIViewController 
{ 
    IBOutlet UILabel * result;  
    NSTimer * timer;     
    int currentTime; 
} 

- (void)populateLabelwithTime:(int)milliseconds; 
-(IBAction)start; 
-(IBAction)pause; 
@end 

定義

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    currentTime = 270000000; // Since 75 hours = 270000000 milli seconds 


} 

-(IBAction)start{ 
    timer = [NSTimer scheduledTimerWithTimeInterval:.01 target:self selector:@selector(updateTimer:) userInfo:nil repeats:YES]; 

} 
-(IBAction)pause{ 
    [timer invalidate]; 

} 
- (void)updateTimer:(NSTimer *)timer { 
    currentTime -= 10 ; 
    [self populateLabelwithTime:currentTime]; 
    } 
- (void)populateLabelwithTime:(int)milliseconds { 
    int seconds = milliseconds/1000; 
    int minutes = seconds/60; 
    int hours = minutes/60; 

    seconds -= minutes * 60; 
    minutes -= hours * 60; 

    NSString * result1 = [NSString stringWithFormat:@"%@%02dh:%02dm:%02ds:%02dms", (milliseconds<0?@"-":@""), hours, minutes, seconds,milliseconds%1000]; 
    result.text = result1; 

} 

Answer 2

使用縮短定時器下面的代碼顯示的時間。

double dblRemainingTime=60; //1 minute 

if(dblRemainingTime >0) 
{ 
    dblRemainingTime -= 1; 
    int hours,minutes, seconds; 
    hours = dblRemainingTime/3600; 
    minutes = (dblRemainingTime - (hours*3600))/60; 
    seconds = fmod(dblRemainingTime, 60); 
    [lblRemainingTime setText:[NSString stringWithFormat:@"%02d:%02d",minutes, seconds]]; 
} 
else 
     alert('Time up buddy');