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

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 allo开发者_如何学运维c]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......

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;

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

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;
}