nstimer

I develop Stop Watch Application. In my application, there are Two UIButtons , StartBtn and StopBtn , And also I use NSTimer . Now, i want to start NSTimer when user click on StartBtn and also stop when your click on StopBtn . I know that NSTimer is stopped by [MyTimerName invalidate]; method but I don't know how to start NSTimer again? The NSTimer class is a bit awkward to use; rather than separating the creation/destruction from the start/stop, it's all rolled together. In other words the timer starts as soon as it's created and stops as soon as it's destroyed. You therefore need to use the

Possible Duplicate: NSTimer doesn't stop In my application I am using NStimer to call an animation function every 3 seconds. I want to stop this timer and called another event while the timer is still running. Is this possible? @interface NSTimer *autoTimer; @implementation // Start timer autoTimer = [NSTimer scheduledTimerWithTimeInterval:(3.0) target:self selector:@selector(autoTimerFired:) userInfo:nil repeats:YES]; // Stop timer: [autoTimer invalidate]; autoTimer = nil; First, you want to keep a pointer to the timer self.packetTimer = [NSTimer timerWithTimeInterval:CONNECTION_TIMEOUT

is it possible to determine whether my UIView is visible to the user or not? My View is added as subview several times into a Tab Bar Controller . Each instance of this view has a NSTimer that updates the view. However I don't want to update a view which is not visible to the user. Is this possible? Thanks mahboudz You can check if: it is hidden, by checking view.hidden it is in the view hierarchy, by checking view.superview != nil you can check the bounds of a view to see if it is on screen The only other thing I can think of is if your view is buried behind others and can't be seen for that

I'm making an application where the exams is going on, so when exam start the, time should start with that. For example 30 minutes and it should reduce like 29:59. How can I implement this? Can anyone please give me a sample example or a easy step by step tutorial that i can follow? Adrian P This code is used to create a countdown timer. Code for .h file. @interface UIMyContoller : UIViewController { NSTimer *timer; IBOutlet UILabel *myCounterLabel; } @property (nonatomic, retain) UILabel *myCounterLabel; -(void)updateCounter:(NSTimer *)theTimer; -(void)countdownTimer; @end Code for .m file.

I want current time in following format in a string. dd-mm-yyyy HH:MM How? Carl Norum You want a date formatter . Here's an example: NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; [formatter setDateFormat:@"dd-MM-yyyy HH:mm"]; NSDate *currentDate = [NSDate date]; NSString *dateString = [formatter stringFromDate:currentDate]; Either use NSDateFormatter as Carl said, or just use good old strftime , which is also perfectly valid Objective-C: #import <time.h> time_t currentTime = time(NULL); struct tm timeStruct; localtime_r(&currentTime, &timeStruct); char buffer[20]; strftime

I'm using an NSTimer like this: timer = [NSTimer scheduledTimerWithTimeInterval:30.0f target:self selector:@selector(tick) userInfo:nil repeats:YES]; Of course, NSTimer retains the target which creates a retain cycle. Furthermore, self isn't a UIViewController so I don't have anything like viewDidUnload where I can invalidate the timer to break the cycle. So I'm wondering if I could use a weak reference instead: __weak id weakSelf = self; timer = [NSTimer scheduledTimerWithTimeInterval:30.0f target:weakSelf selector:@selector(tick) userInfo:nil repeats:YES]; I've heard that the timer must be

In my app I have a NSTimer, and a selector - (void)TimerCount . I also have a integer int CountNum , and every 0.01 second, it increases by 1 ( CountNum = CountNum + 1 ). Timer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(TimerCount) userInfo:nil repeats:YES]; And I want the timer to resume thought the app is terminated or it entered background. How can I do this? If your application is terminated , you will not be able to continue processing. To operate in the background, there are such things as background tasks, but it sounds like your use case does not

I have an app using an NSTimer at centisecond (0.01 second) update intervals to display a running stopwatch in String Format as 00:00.00 (mm:ss.SS). (Basically cloning the iOS built-in stopwatch to integrate into realtime sports timing math problems, possibly needing millisecond accuracy in the future) I use (misuse?) the NSTimer to force-update the UILabel. If the user presses Start, this is the NSTimer code used to start repeating the function: displayOnlyTimer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: Selector("display"), userInfo: nil, repeats: true) And here