Passing data from a modal view - objective-c

Question

Storyboard
ViewController
SecondViewController
I'd like to pass data (aNumber, a variable NSString) in LabelNumber (in ViewController) from modal SecondViewController after entering numbers in TextFieldNumber using a decimal pad.
I add a close button (bar button item) in the SecondViewController and connect to Segue (mySegue).
In ViewController there's a Round Rect Button linked to SecondViewController
Here's the code in ViewController.m
#import "ViewController.h"
#import "SecondViewController.h"
#interface ViewController ()
#property (weak, nonatomic) IBOutlet UILabel *LabelNumber;
#property (weak, nonatomic) SecondViewController * SecondScreen;
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.identifier isEqualToString: #"mySegue"]){
self.SecondScreen = segue.destinationViewController;
self.SecondScreen.aNumber = self.LabelNumber.text
}
- (IBAction)close:(UIStoryboardSegue*)sender {
if([sender.identifier isEqualToString:#"mySegue"] ){
self.LabelNumber.text = self.SecondViewController.aNumber;
}
In SecondViewController.h i've this code:
#import <UIKit/UIKit.h>
#interface SecondViewController : UIViewController
#property (strong, nonatomic) NSString* aNumber;
#end
In SecondViewController.m i've this code:
#import "ViewController.h"
#import "SecondViewController.h"
#interface SecondViewController () <UITextFieldDelegate>
#property (strong, nonatomic) IBOutlet UITextField *TextFieldNumber;
#end
- (void)viewDidLoad
{
[super viewDidLoad];
[self.TextFieldNumber becomeFirstResponder];
self.TextFieldNumber.delegate = self;
self.TextFieldNumber.text = self.aNumber;
}
- (IBAction)getValue:(UITextField *)sender {
self.aNumber = self.TextFieldNumber.text ;
[self.TextFieldNumber resignFirstResponder];
}
At last, i've added always in SecondViewController.m that, even if i don't want to close the keyboard but i want it to stay always ON and would like to catch the TextNumber value (aNumber) in close button (modal unwind).
-(BOOL) textFieldShouldReturn:(UITextField *)textField{
if (textField == self.TextFieldNumber)
[self.TextFieldNumber resignFirstResponder];
return YES;
}

Answer 1

If I understood the question correctly, you have two options:
Assign the FirstViewController as delegate of SecondViewController, so that when you dismiss modal you can also call [self.delegate secondViewControllerWillDismiss:value]
Make the FirstViewController listen for a custom notification, let's say "SecondViewControllerDismissNotification", and made SecondViewController send this NSNotification when dismiss. In this case you will have to write your parameter in a NSDictionary to be passed along with the notification itself.
If it's not clear I can write little example.