Objective C how to stop infinte loop while moving from first VC to 2nd

Question

I am trying to build a splash screen so I want the 1st View Controller to move to 2nd ViwController automatically after 3.0 sec I have tried the below method but an infinite loop has started what should i do ,how should I stop on second view controller.

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    NSLog(@"%p", self);
    NSLog(@"1st Controller");

    [self.navigationController setNavigationBarHidden:YES animated:YES];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{


        [self loadingNextView];
      });

}

    - (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}
- (void)loadingNextView{

    LoginViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
    [self.navigationController pushViewController:viewController animated:true];
}
//LoginViewController.h
@interface LoginViewController : ViewController

@end
//LoginViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    NSLog(@"2nd View Controller");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

see after three seconds how the loop is working .

The `performSelector:withObject:afterDelay:` starts the `NSDefaultRunLoopMode`. Why don't you use `dispatch_after` as you commented out? — nynohu, Jan 05 '17 at 07:57
@nynohu sir I have tried in both the ways then also the problem is just the same let me update the changes. — Harshit Goel, Jan 05 '17 at 07:58
If it still call `loadingNextView`, check your `viewWillAppear`, was it called many times? — nynohu, Jan 05 '17 at 08:01
@nynohu previously I had used the same thing but this is the first time I am having problem. and after reaching to second View controller how is it dismissing it back to first View controller ? — Harshit Goel, Jan 05 '17 at 08:03
How is the infinite loop starting? What's your second viewcontrollers code in viewDidLoad / viewDidAppear? — Lefteris, Jan 05 '17 at 08:14
You didn't show me the viewDidAppear, but I guess you are not using it. Then your next bet is to look in storyboard. You might have a segue that's being performed when the second view controller appears... — Lefteris, Jan 05 '17 at 08:23
Just show more little: snippet that you create and display ViewController 1. And it should be better if you show full your ViewController1 and ViewController2. In your current snippet, it seems no problems. — nynohu, Jan 05 '17 at 08:31
@Harshit Goel, `NSLog(@"please stop");` this line code I do not understand, what mean of your "stop infinte loop" ? you can edit your post more detail. — aircraft, Jan 05 '17 at 09:07
It seems other VC1 was created after you back from VC2. Try to put `NSLog(@"%p", self);` to your VC1 `viewDidLoad`. Check the address printed is same or not? — nynohu, Jan 05 '17 at 09:21
It means now you create new VC1 each time you back from VC2. Check your project and find where you implement that. — nynohu, Jan 05 '17 at 23:59
@nynohu http://stackoverflow.com/questions/41506009/objective-c-scroll-view-not-working-when-keyboard-appears-and-dissapears?noredirect=1#comment70217752_41506009 — Harshit Goel, Jan 06 '17 at 15:51

score 1 · Answer 1 · answered Jan 05 '17 at 08:28

1

Why don't you use NSTimer class. Simply create a timer for 10 seconds when 10 seconds passed timer will trigger the event and in that event you can move to another controller. Create a timer like this

[NSTimer scheduledTimerWithTimeInterval:10.0
        target:self
        selector:@selector(targetMethod:)
        userInfo:nil
        repeats:NO];



    - (void)targetMethod:(NSTimer*)timer {
        [self loadingNextView];
    }

answered Jan 05 '17 at 08:28

Usman Javed

2,437
1
17
26

What did happen please tell. – Usman Javed Jan 05 '17 at 09:09
I have tried your way too but i think the problem is somwhere else just have a look at the updated question – Harshit Goel Jan 05 '17 at 09:14
http://stackoverflow.com/questions/41506009/objective-c-scroll-view-not-working-when-keyboard-appears-and-dissapears?noredirect=1#comment70217752_41506009 – Harshit Goel Jan 06 '17 at 15:52

Gulliva · Answer 2 · 2017-01-05T08:41:11.020

0

Try this

[NSTimer scheduledTimerWithTimeInterval:1.0 repeats:false block:^(NSTimer * _Nonnull timer) {
    [self loadingNextView];
}];

So a little advise, you should think about presenting a loginViewController instead pushing it to the NavigationController stack. If you push it, you have to remove the back buttons if you don't want the user to come back to the other ViewController. If you present it you can be sure that the user can't go back to the firstVc without entering his login data.

In the second Vc you then can dismiss the Vc or you can present a new ViewController.

[self presentViewController:vc animated:YES completion:nil];

edited Jan 05 '17 at 08:41

answered Jan 05 '17 at 08:03

Gulliva

488
2
10

Can you describe what happens? Also infinite loop? – Gulliva Jan 05 '17 at 08:21
Sir it moves to second VC after 1 sec but as it moves to 2nd it doesnt stop at 2nd it keeps on dismissing to 1st and then again moves to second, this happens again and again – Harshit Goel Jan 05 '17 at 08:24
So can you post the coding from the second Vc? I tried it, and it works for me. But the method has to be a little diffrent. I edited the Method... – Gulliva Jan 05 '17 at 08:27

aircraft · Answer 3 · 2017-01-05T08:40:15.660

It is easy to do, you can add a property to judge if is first come in the vc1:

The result:

In fitst VC:

#import "ViewController.h"
#import "LoginViewController.h"

@interface ViewController ()

@property(nonatomic, assign) BOOL isFirstTime;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    _isFirstTime = YES;
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
/*  [self performSelector:@selector(loadingNextView)
 withObject:nil afterDelay:1.0f]; */

    if (_isFirstTime == NO) {

        return;
    }

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{


    [self loadingNextView];
    _isFirstTime = NO;
    });

}
- (void)loadingNextView{

    LoginViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
    [self.navigationController pushViewController:viewController animated:true];
}

http://stackoverflow.com/questions/41506009/objective-c-scroll-view-not-working-when-keyboard-appears-and-dissapears?noredirect=1#comment70217752_41506009 — Harshit Goel, Jan 06 '17 at 15:52

score 0 · Answer 4 · answered Jan 05 '17 at 09:24

You can achieve you goal by using this.

#import "DrawingViewController.h"
#import "SecondViewController.h"

@interface DrawingViewController ()

@end

@implementation DrawingViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    [button removeFromSuperview];

    [NSTimer scheduledTimerWithTimeInterval:3.0 target:self selector:@selector(target:) userInfo:nil repeats:NO];

}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)target:(NSTimer*)timer {

    SecondViewController* controller = [self.storyboard instantiateViewControllerWithIdentifier:@"SecondViewController"];
    [self.navigationController pushViewController:controller animated:YES];
}

score 0 · Answer 5 · answered Jan 05 '17 at 10:43

Finally got the answer.

    #import "ViewController.h"
    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        NSLog(@"%p", self);
        [self.navigationController setNavigationBarHidden:YES animated:YES];
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 3 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{

            NSLog(@"1st controller");
            [self loadingNextView];
        });

    }


    - (void)didReceiveMemoryWarning {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }

    - (void)loadingNextView{

        UIViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
        [self.navigationController pushViewController:viewController animated:true];
    }
//LoginViewController.h
#import "ViewController.h"

@interface LoginViewController : UIViewController

@end
//LoginViewController.m
#import "LoginViewController.h"

@interface LoginViewController ()

@end

@implementation LoginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    NSLog(@"2nd View Controller");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

Objective C how to stop infinte loop while moving from first VC to 2nd

5 Answers5

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