暂停后恢复定时器吗？

Question

我看过其他暂停/恢复计时器的问题，但无法弄清楚如何解决我的问题。我只有一个简单的计时器标签和两个按钮，一个开始和一个停止按钮。让我知道你是否需要关于我的项目的更多信息来帮助回答我的问题。任何人都可以看到我要去哪里吗？

- (void)updateTimer 
{ 
    // Create date from the elapsed time 
    NSDate *currentDate = [NSDate date]; 
    NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:self.startDate]; 
    NSDate *timerDate = [NSDate dateWithTimeIntervalSince1970:timeInterval]; 

    // Create a date formatter 
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
    [dateFormatter setDateFormat:@"HH:mm:ss"]; 
    [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]]; 

    // Format the elapsed time and set it to the label 
    NSString *timeString = [dateFormatter stringFromDate:timerDate]; 
    self.stopwatchLabel.text = timeString; 
} 

- (void)updateResumeTimer 
{ 
    // Format the elapsed time and set it to the label 
    NSString *timeString = [dateFormat stringFromDate:dateFor]; 
    self.stopwatchLabel.text = timeString; 
} 

- (IBAction)onStartPressed:(id)sender { 

NSString *isItEqual = self.stopwatchLabel.text; 

if ([isItEqual isEqualToString:@"00:00:00"]) { 
    self.startDate = [NSDate date]; 

    // Create the stop watch timer that fires every 10 ms 
    self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0 
                  target:self 
                 selector:@selector(updateTimer) 
                 userInfo:nil 
                  repeats:YES]; 
} 
else { 
    // Create the stop watch timer that fires every 10 ms 
    self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0 
                  target:self 
                 selector:@selector(updateResumeTimer) 
                 userInfo:nil 
                  repeats:YES]; 

} 
} 


- (IBAction)onStopPressed:(id)sender { 
resumeText = self.stopwatchLabel.text; 
NSLog(@"Timer is %@", resumeText); 

dateFormat=[[NSDateFormatter alloc]init]; 
[dateFormat setDateFormat:@"HH:mm:ss"]; 
dateFor=[dateFormat dateFromString:resumeText]; 
[dateFormat setDateFormat:@"HH:mm:ss"]; 

[self.stopWatchTimer invalidate]; 
self.stopWatchTimer = nil; 

[self updateTimer]; 
} 

Answer 1

您需要添加属性

@property (assign, nonatomic) NSTimeInterval previousTimeInterval; 

只需复制的代码下面的线，它应该工作。

- (void)updateTimer 
{ 
    // Create date from the elapsed time 
    NSDate *currentDate = [NSDate date]; 
    NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:self.startDate]; 
    timeInterval += self.previousTimeInterval; 
    NSDate *timerDate = [NSDate dateWithTimeIntervalSince1970:timeInterval]; 
    self.dateFor = timerDate; 

    // Create a date formatter 
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
    [dateFormatter setDateFormat:@"HH:mm:ss"]; 
    [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]]; 

    // Format the elapsed time and set it to the label 
    NSString *timeString = [dateFormatter stringFromDate:timerDate]; 

    self.stopwatchLabel.text = timeString; 
} 

- (IBAction)onStartPressed:(id)sender { 

    self.startDate = [NSDate date]; 

    // Create the stop watch timer that fires every 10 ms 
    self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0 
                 target:self 
                selector:@selector(updateTimer) 
                userInfo:nil 
               repeats:YES]; 

    //Disable start button and enable stop 
    self.startButton.enabled = NO; 
    self.stopButton.enabled = YES; 
} 


- (IBAction)onStopPressed:(id)sender 
{ 
    [self.stopWatchTimer invalidate]; 
    self.stopWatchTimer = nil; 

    self.previousTimeInterval = [self.dateFor timeIntervalSince1970]; 
    // enable start button and disable stop button 
    self.startButton.enabled = YES; 
    self.stopButton.enabled = NO; 
}