Question

I am studying Object-C and I am writing a test app to learn.
This is an easy app, where in the first View i press a button, go in the second View (I used a curl animation)fill a text field and then press a button, pass the content of the field in the first view.

So I created the 2 Views, placed a button and a Label in the first View and linked the button from the first View to the second View using the right mouse click and drag a line with action Modal.

In the second View, I wrote the following code:

ViewController2.h

@property (weak, nonatomic) IBOutlet UITextField *firstTextField;
@property (strong, nonatomic) NSString *stringFromVC2;

- (IBAction)passTextToVC2Button:(id)sender;

ViewController2.m

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

    self.firstTextField.delegate = self;
}

- (IBAction)passTextToVC2Button:(id)sender {
    ViewController *VC2 = [self.storyboard instantiateViewControllerWithIdentifier:@"wb_ViewController"];

    VC2.stringFromTextField1 = self.firstTextField.text;

    [self presentViewController:VC2 animated:YES completion:nil];
}

The app works, but when I press the button from ViewController2, and go back to ViewController, it doesn’t animate the Curl animation, just it appears from the bottom of the page a new window (the ViewController) under the ViewController opened with the Curl animation.

I also tried to use:

[self dismissViewControllerAnimated:YES completion:nil];

instead of:

[self presentViewController:VC2 animated:YES completion:nil];

in this case, it closes the second view but the Label in the first View isn’t display with the text I inserted in the second View.

As I told you, I am studying so I am a beginner, please be patient.

Answer 1

The way to do this is to define a delegate protocol that your first view controller conforms to, and your second view controller can send a message to to pass back the value.

I’ve had to answer this question a few times so I created an very simple example project to show exactly what I mean. Download it and see how to pass data back down the controller stack.

Update

I’ve changed the sample to an new project for iOS6 with ARC and Storyboards.