Can not call method from another view controller in Objective C, iPhone SDK

At my StartWorkoutViewController.m I trigger:

    #import "WorkoutViewController.h"
@implementation StartWorkoutViewCon开发者_运维问答troller

- (IBAction) start
{   
[firstViewController performSelector:@selector(callMyAction)];
WorkoutViewController *ViewCon = [[WorkoutViewController alloc]init];
[ViewCon callMyAction];
[ViewCon release];
}

then at my WorkOutViewController.h I added this:

- (void)callMyAction;

and at my WorkOutViewController.m I added this:

#import "StartWorkoutViewController.h"

-(void)viewWillAppear:(BOOL)animated{
    NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/achtergrondgeluid.mp3", [[NSBundle mainBundle] resourcePath]]];

    NSError *error;
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
    audioPlayer.numberOfLoops = -1;
    [audioPlayer play];


}
-(void)callMyAction{
    NSLog(@"suckers");

    [audioPlayer pause];
}

Now my NSLog (@"suckers") triggers very well from the StarWorkoutViewController, but for some reason the audioPlayer does nothing, any idea? Also setting labels in the Workout ViewController from the callMyAction in this file. Don't work! Any idea? Thanks!

The reason nothing is happening is because your are calling the pause method before the player even starts playing. viewWillAppear does not get called until it is visually on the screen. It actually doesn't always get called even then but that is another issue entirely. So if you want to pause the player it needs to actually be playing. If you put that viewWillAppear code in viewDidLoad it will probably work as expected.

Currently your code is doing this:

1. Load WorkoutViewController
2. Pause Audio
3. WorkourViewController become visible (actually this may never happen as I am not seeing it being added to any windows or anything).
4. Plays audio.