How to call a method every x seconds in Objective-C using NSTimer?

Question

I am using Objective-C, Xcode 4.5.1 and working on an app for the iPhone.

I have a method A in which I want to call another method B to do a series of calculations e

Answer 1

Well you are trying to call an normal C method, NSTimer can't to that.

The target is the an instance of the class on which to call the selector, this selector adn not select. The selector here is a SEL type which you can create with the @selector(METHOD_NAME) function.

For example this will call the handleTimer : ever 0.1 second: (For this example the AppDelegate is used):

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //SNIP, some code to setup the windos.   

    [NSTimer scheduledTimerWithTimeInterval:0.1f target:self selector:@selector(handleTimer:) userInfo:nil repeats:YES];
    return YES;
}

- (void) handleTimer:(NSTimer *)timer {
    // Hanlde the timed event.
}