what should go into completion in presentViewController?

Question

I am using presentViewController in xcode and not sure what should go into completion.

The code given by xcode documentation:

- (void)presentViewController:(UIViewController *)viewControllerToPresent animated: (BOOL)flag completion:(void (^)(void))completion NS_AVAILABLE_IOS(5_0);

Example that i am using:

[self presentViewController:second animated:YES completion:<#^(void)completion#>];

What should go into completion?

Answer 1

You can use the below code instead:

[self presentViewController:second animated:YES completion:^{ }];

or you can simply pass NULL

[self presentViewController:second animated:YES completion:NULL];

The completion block is used for doing any tasks after presenting the view controller , the code written inside the completion block will execute only after the view is presented.

Answer 2

@try this

[self presentViewController:second animated:YES completion:^{[self animationCompleted];}];


-(void)animationCompleted{

   // Whatever you want to do after finish animation

    NSLog(@"Animation Completed")

}

if you don't want to do anything on completion of animation

[self presentViewController:second animated:YES completion:NULL];

Answer 3

You can use the following code for the presenting the view

  [[self navigationController] dismissViewControllerAnimated:YES completion:NULL];

Following is the code for the that

SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
[self presentViewController:second animated:YES completion:nil];

For more detail check the apple forum discussion

Answer 4

Swift 2.0

---

Handle something on completion

viewController.presentViewController(anotherViewController, animated: true, completion: {
    // Whatever you'd like to do when presentViewController completes :)
})

Or do nothing on completion

viewController.presentViewController(anotherViewController, animated: true, completion: nil)