CODEWITHSUNDEEP
iphonenstimer
Ian Vink
Ian Vink

Reputation: 68840

iphone NStimer start in 2 seconds

I am trying to have a block of code run 2 seconds after I 'start' it.

I think the NSTimer can do this but can't figure it out.

Upvotes: 6

Views: 8314

Answers (4)

P.O
P.O

Reputation: 101

You can also use some handy code :

NSObject+PerformBlock.h

@interface NSObject (PerformBlock)

- (void)performBlock:(void(^)(void))block waitUntilDone:(BOOL)wait;
- (void)performBlock:(void(^)(void))block afterDelay:(NSTimeInterval)delay;
- (void)performBlock:(void(^)(void))block repeatCount:(NSUInteger)repeatCount timeInteval:(NSTimeInterval)timeInterval;

@end

NSObject+PerformBlock.m

@interface NSObject (PerformBlockHidden)

- (void)performBlock:(void(^)(void))block;

@end

@implementation NSObject (PerformBlock)

- (void)performBlock:(void(^)(void))block {
    block();
}

- (void)performBlock:(void(^)(void))block waitUntilDone:(BOOL)wait {
    [self performSelector:@selector(performBlock:) onThread:nil withObject:[[block copy] autorelease] waitUntilDone:wait];
}

- (void)performBlock:(void(^)(void))block afterDelay:(NSTimeInterval)delay {
    [self performSelector:@selector(performBlock:) withObject:[[block copy] autorelease] afterDelay:delay];
}

- (void)performBlock:(void(^)(void))block repeatCount:(NSUInteger)repeatCount timeInteval:(NSTimeInterval)timeInterval {
    for (NSInteger repetition = 0; repetition < repeatCount; repetition++)
        [self performBlock:block afterDelay:(repetition*timeInterval)];
}

@end

Then just import NSObject+PerformBlock.h and call :

[myObject performBlock:^{
    // Code you want to perform after 2secs
} afterDelay:2];

Upvotes: 8

progrmr
progrmr

Reputation: 77301

NSTimer can be used, but another option is to use performSelector:withObject:afterDelay: It's basically like a method call (message send) that happens later.

This example will send a doStuff: message after a delay:

[self performSelector:@selector(doStuff:) withObject:self afterDelay:2];

which causes this method to get invoked 2.0 seconds later:

-(void)doStuff:(id)sender 
{
    /// do something
}

Upvotes: 19

Jason Webb
Jason Webb

Reputation: 8020

The following will do what you need:

 NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval: 2 
                                   target:self 
                                   selector:@selector(handleTimer:) 
                                   userInfo:nil
                                   repeats:NO];

Then the delegate function:

-(void)handleTimer: (NSTimer *) timer 
{       
   //code
}

Upvotes: 12

fbrereto
fbrereto

Reputation: 35945

You should be able to set the NSTimeInterval to 2.0 seconds and it should fire after that amount of time. What are you seeing? What is the code you are using to invoke the timer?

Upvotes: 2

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