Question

I’m following Facebook’s iOS tutorial for logging out.

I added the tutorial’s code into my delegate .m file. Ran it and when I clicked on the Logout button, it crashes. I don’t know what the error means. The log window shows:

[S3DEngine_AppDelegate logoutButtonClicked]: unrecognized selector sent to instance 0xb011dd0

I’m using iPhone Simulator 5.0, XCode 4.2.
The difference in the tutorial is that I am NOT using applicationDidFinishLauchingWithOptions:. I tried this function too, but it’s the same error.

Thanks for any help

- (void)applicationDidFinishLaunching:(UIApplication *)application 
{
    // Facebook
    // Add the logout button
    UIButton *logoutButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    logoutButton.frame = CGRectMake(40, 40, 200, 40);
    [logoutButton setTitle:@"Log Out" forState:UIControlStateNormal];
    [logoutButton addTarget:self action:@selector(logoutButtonClicked)
           forControlEvents:UIControlEventTouchUpInside];   
    [self.viewController.view addSubview:logoutButton];


    // Disable idle timer
    //
    [application setIdleTimerDisabled:YES] ;

    // Configure and start the accelerometer
    //
    [[UIAccelerometer sharedAccelerometer] setUpdateInterval:kAccelerometerFrequency] ;
    [[UIAccelerometer sharedAccelerometer] setDelegate:self] ;

    // Create the view controller
    //
    [window addSubview:viewController.glView];
    [window makeKeyAndVisible];

    // Configure and start animation
    //
    viewController.glView.iAnimationInterval = kAnimationFrequency ;
    [viewController.glView startAnimation];       

    // Configure ans start slpash view
    //
    CGRect frame = [[UIScreen mainScreen] bounds];
    splashView = [[UIImageView alloc] initWithFrame:frame];
    splashView.image = [UIImage imageNamed: @"Default.png"];
    [window addSubview:splashView];
    [window bringSubviewToFront:splashView];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.5];
    [UIView setAnimationTransition:UIViewAnimationTransitionNone forView:window cache:YES];
    [UIView setAnimationDelegate:self]; 
    [UIView setAnimationDidStopSelector:@selector(startupAnimationDone:finished:context:)];
    splashView.alpha = 0.0;
    [UIView commitAnimations];

    // Play default movie if any
    //
    [viewController.glView playDefaultMovieIfAny];

    facebook = [[Facebook alloc] initWithAppId:@"105441111111111" andDelegate:self];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    if ([defaults objectForKey:@"FBAccessTokenKey"]
        && [defaults objectForKey:@"FBExpirationDateKey"])
    {
        facebook.accessToken = [defaults objectForKey:@"FBAccessTokenKey"];
        facebook.expirationDate = [defaults objectForKey:@"FBExpirationDateKey"];
    }

    if (![facebook isSessionValid])
    {
        [facebook authorize:nil];
    }

}

- (void) logoutButtonClicked:(id)sender 
{
    [facebook logout];
}

- (void) fbDidLogout 
{
    // Remove saved authorization information if it exists
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    if ([defaults objectForKey:@"FBAccessTokenKey"]) {
        [defaults removeObjectForKey:@"FBAccessTokenKey"];
        [defaults removeObjectForKey:@"FBExpirationDateKey"];
        [defaults synchronize];
    }
}

Answer 1

Do like this…

[logoutButton addTarget:self action:@selector(logoutButtonClicked:)
           forControlEvents:UIControlEventTouchUpInside];

OR

- (void) logoutButtonClicked
{
    [facebook logout];
}