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I'm new to iOS and Its developing.i have read Xcode old style passing data between view controllers.there i have seen lot of things going with xib files.please find below the code i have used to pass data in-between ViewControllers.but there in customelink(please find DetailViewController.m)there I'm getting Null value.please help me to get String value there.and kind enough to explain what are the mistakes I've done here.

EssentialInfoController.h

#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface Essentialinfocontroller : UIViewController
@end

EssentialInfoController.m

#import "Essentialinfocontroller.h"

@interface Essentialinfocontroller ()
@end

@implementation Essentialinfocontroller


- (void)viewDidLoad
{
    [super viewDidLoad];
    DetailViewController * customelink= [DetailViewController alloc ];
    customelink.link=@"https://www.facebook.com";



}

@end

DetailViewController.h

#import <UIKit/UIKit.h>

@interface DetailViewController : UIViewController
@property(weak,nonatomic)NSString * link;

@end

DetailViewController.m

 #import "DetailViewController.h"

    @interface DetailViewController ()

    @property(nonatomic,weak)NSString *customelink;
    @end

    @implementation DetailViewController
    @synthesize link;

    @synthesize customelink;


    - (void)viewDidLoad
    {
        [super viewDidLoad];
        self.customelink=self.link;


        NSLog(@"link--> %@",customelink);// here 2014-07-06 21:21:51.469 WADTourisum[880:60b] link--> (null)

    }

    @end
Cœur
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VenushkaT
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  • possible duplicate of [Passing Data between View Controllers](http://stackoverflow.com/questions/5210535/passing-data-between-view-controllers) – nhgrif Jul 06 '14 at 16:16
  • What is this - DetailViewController * customelink= [DetailViewController alloc ]? You should never ever have an alloc without an init. But you probably don't want alloc init either depending on where you're making your view controllers. Are you using a storyboard? – rdelmar Jul 06 '14 at 16:18
  • @rdelmar yes I'm using story board – VenushkaT Jul 06 '14 at 16:23
  • @nhgrif here i'm using story board.the previous one isnt based on story board. – VenushkaT Jul 06 '14 at 16:26
  • You don't instantiate a storyboard view controller with alloc init, you use instantiateViewControllerWithIdentifier:. – rdelmar Jul 06 '14 at 16:27
  • Can you explain what you tried in the question I linked that didn't work? There's code based on storyboard data transfers in that link. – nhgrif Jul 06 '14 at 16:29
  • http://stackoverflow.com/a/9736559/2792531 Scroll down to **Passing Data Forward using Segue's** – nhgrif Jul 06 '14 at 16:30
  • @rdelmar he just logs to see the result in `detailVC`, so alloc init will be fine. – Pham Hoan Jul 06 '14 at 16:30
  • @PhamHoan, but I assume that he will want to see his view controller at some point, and alloc init will not work for that. – rdelmar Jul 06 '14 at 16:33

1 Answers1

1
DetailViewController * customelink= [DetailViewController alloc ];

should be

DetailViewController * customelink= [[DetailViewController alloc ] init];

and 

@property(weak,nonatomic)NSString * link;

should be

@property(strong,nonatomic)NSString * link;

and log it

NSLog(@"link--> %@",self.link);

you don't need this one

@property(nonatomic,weak)NSString *customelink;

if you use storyboard and segue then you have to implement -(void)prepareForSegue method.

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Make sure your segue name in storyboard is the same as this line
    if ([[segue identifier] isEqualToString:@"YOUR_SEGUE_NAME_HERE"])
    {
        // Get reference to the destination view controller
        YourViewController *vc = [segue destinationViewController];

        // Pass any objects to the view controller here, like...
        [vc setMyObjectHere:object];
    }
}

assume that you got a button to move from essentialVC to detailVC, in you IBAction, call this method:

[self performSegueWithIdentifier:@"YOUR_SEGUE_NAME_HERE" sender:self];

this is just a brief answer. I suggest you read about UINavigationController first, it's much easier to use compared to segue, IMHO.

Pham Hoan
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