Question

I know this question as been asked over and over but it’s still quite obscure to me, so I guess making an example with my code instead will probably be easier .

I know that you can use :

• A global variable, ( not good practice ).
• Use a delegate
• Use a singleton

Say I’ve got this piece of code here in my first view controller header :

#import <UIKit/UIKit.h>


@interface FirstViewController : UIViewController {

    IBOutlet UITextField *Te;
NSInteger evTe;
}


@property (nonatomic, retain) UITextField *Te;
@property (nonatomic) NSInteger evTe;


- (IBAction) makeKeyboardGoAway;

@end

and then this in my implementation file

#import "FirstViewController.h"


@implementation FirstViewController

@synthesize Te;

- (IBAction) makeKeyboardGoAway;
{
    [Te resignFirstResponder];  
    evTe = [Te.text intValue];
}

How would I call evTe in my SecondViewController ? ( maybe using a delegate ?) .

This is what I’ve got in the second view Controller, header :

@interface SecondViewController : UIViewController {


        NSInteger evTe;

}



@property (nonatomic) NSInteger evTe;

and implementation :

- (IBAction) makeKeyboardGoAway;
{



    FirstViewController *first = [[FirstViewController alloc] init];
    first.evTe = self.evTe;

    NSLog(@"second value is %i",evTe);

}

Thanks a lot !

---

Edit for Tob

FirstViewController.m

- (IBAction) makeKeyboardGoAway;
{
    evTe = [Te.text intValue];
    NSLog(@"The value of integer num is %i", evTe);

    NSDictionary *changedValues = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:evTe] forKey:@"evTe"];
    [[NSNotificationCenter defaultCenter] postNotificationName:@"evTeChanged" object:self userInfo:changedValues];


}

SecondViewController.m

 - (void)viewDidLoad {
     [super viewDidLoad];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(methodToCall:) name:@"evTeChanged" object:nil];

 }

- (void)methodToCall:(NSNotification *)aNotification{

    NSDictionary *changedValues = [[aNotification userInfo]  objectForKey:@"evTe"];               
    NSString *dictionaryString = [changedValues description];
    NSLog(@"Notification returning %d",dictionaryString);

}

Unfortunately I’m not getting any log from the SecondView ..

Answer 1

By creating a @property called evTe or whatever in both view controllers.

If the FirstViewController is responsible for creating the SecondViewController you could store the value of evTe in a property in FirstViewController and then after you have created the SecondViewController you set the evTe property there as well.

- (IBAction) makeKeyboardGoAway;
{
    [Te resignFirstResponder];  
    self.evTe = [Te.text integerValue];
}

// other method where SecondViewController is created

SecondViewController* second = [[SecondViewController alloc] init];
second.evTe = self.evTe;
// do what ever

–Edit–

@interface FirstViewController : UIViewController {

    IBOutlet UITextField *Te;
    NSInteger evTe;

}

@property (nonatomic, retain) UITextField *Te;
@property (nonatomic) NSInteger evTe;