How can i call NStimer form one viewcontroller from unother viewcontroller? - iphone

Question

At first time i call the timer like this in Third viewcontroller
timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(targetMethod) userInfo:nil repeats:NO];
Then timer called the targetMethod
-(void)targetMethod
{
First * sVC = [[First alloc] initWithNibName:#"First" bundle:[NSBundle mainBundle]];
[self presentModalViewController:sVC animated:YES];
[sVC release];
[timer invalidate];
}
First viewcontroller opened..
In First viewcontroller had one button.In button action
i wrote
- (IBAction) Action:(id)sender
{
[self dismissModalViewControllerAnimated:YES];
Third *BVC=[[Third alloc]init];
[Bvc TimerStart]; //Timestart is function i start timer in this function..
//i want to call Third viewcontroller timer function this place
}
timer started..But view didn't open (first )viewcontroller.......
Please help me......

Answer 1

Bala,
Place the NSTimer object in the App Delegate .h file, include that .h file in wherever you use the timer. This will allow the NSTimer to be a global timer which you can call from any other view that includes the app delegate header file.
In app delegate .h file (in the appropriate areas):
NSTimer *delayTimer;
#property (nonatomic, retain) NSTimer *delayTimer;
Synthesize this in the app delegate .m file (remember to release it in dealloc):
#synthesize delayTimer;
Then in whichever views you use the timer in, access it like this:
// get global variable
SomeNameHereAppDelegate *mainDelegate = (SomeNameHereAppDelegate *)[[UIApplication sharedApplication] delegate];
mainDelegate.delayTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(targetMethod) userInfo:nil repeats:NO];
Then when you want to invalidate it from somewhere, you just do this:
[mainDelegate.delayTimer invalidate];
mainDelegate.delayTimer = nil;

Answer 2

What if if i need to have a count down timer which should be shared among the view controllers.do i have to make it in the app delegate where the remaining seconds could be an ivar also in app delegate with property?
In this case i would post notification from the timer handler after updating the remaining seconds

Answer 3

In AppDelegate.h
#property int timePassed;
In AppDelegate.m
#synthesize timePassed;
In ViewController.h
#property (weak, nonatomic)NSTimer *timer;
#property (weak, nonatomic) IBOutlet UILabel *time;
In ViewController.m
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
AppDelegate *delegate = (AppDelegate*) [[UIApplication sharedApplication] delegate];
delegate.timePassed = 180;
timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(TimePasses) userInfo:nil repeats:YES];;
}
-(void) TimePasses{
AppDelegate *delegate = (AppDelegate*) [[UIApplication sharedApplication] delegate];
delegate.timePassed = delegate.timePassed - 1;
NSLog(#"TimePasses %d", delegate.timePassed);
int minuts = delegate.timePassed / 60;
int seconds = delegate.timePassed - (minuts * 60);
NSString *timerOutput = [NSString stringWithFormat:#"%2d:%.2d", minuts, seconds];
time.text = timerOutput;
}
In SecondViewController.h
#property (weak, nonatomic)NSTimer *timer;
#property (weak, nonatomic) IBOutlet UILabel *time;
In SecondViewController.m
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(TimePasses) userInfo:nil repeats:YES];;
}
-(void) TimePasses{
AppDelegate *delegate = (AppDelegate*) [[UIApplication sharedApplication] delegate];
NSLog(#"TimePasses in 2 %d", delegate.timePassed);
int minuts = delegate.timePassed / 60;
int seconds = delegate.timePassed - (minuts * 60);
NSString *timerOutput = [NSString stringWithFormat:#"%2d:%.2d", minuts, seconds];
time.text = timerOutput;
}