Pass NSString between two DetailViewController

Question

MasterViewController.m

#import "DetailViewController.h"

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
    {
    if ([segue.identifier isEqualToString:@"DetailViewControllerSeque"]) {
        DetailViewController *detailView = [segue destinationViewController];

        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

        theList = [app.listArray objectAtIndex:indexPath.row];

        detailView.theList = theList;

        // String to pass to DetailViewController
        detailView.string2pass = @"this is a passing string";
    }
}

DetailViewController.h

NSString *string2pass;

@property (retain, nonatomic) NSString *string2pass;

DetailViewController.m

NSLog(@"%@", string2pass);

Output: (null)

What I am doing wrong?

Did u synthasize that property? Once u can print the NSLog for detailView.string2pass before assigning.. — kalyani puvvada, Sep 16 '13 at 12:47
I think this is more detailed try this http://stackoverflow.com/questions/5210535/passing-data-between-view-controllers?rq=1 — Hemant Singh Rathore, Sep 16 '13 at 13:05
Are you sure detailView is not nil? NSLog(@"%@", detailView) after you get it from the segue. — bandejapaisa, Sep 16 '13 at 13:20

bandejapaisa · Accepted Answer · 2013-09-16T12:51:48.047

4

Unless you have this in your implementation, it won't work as you expected.

@synthesize string2pass = string2pass;

..or you can fix it by deleting the line:

NSString *string2pass;

Your log is logging the value of string2pass variable you declared. But there is another variable _string2pass.

NSLog(@"%@", string2pass);

The @property you declared, is backed by a variable name _string2pass if you don't explicitly write a @synthesize statement. Not writing an @sythesize statement is the same as declaring one like so:

@synthesize string2pass = _string2pass;

edited Sep 16 '13 at 12:51

answered Sep 16 '13 at 12:46

bandejapaisa

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Thanks for helping me, but even when I remove `NSString *string2pass;` and I add `@synthesize string2pass = _string2pass;` I´m still getting (null) :( – Lorenz Sep 16 '13 at 13:11
You don't actually need to explicitly write that synthesize statement if you don't want, it's no harm it being there - but if you don't write it, it is created for you. If you did that, then you probably won't compile now without changing your NSLog statement to read NSLog(@"%@", self.string2pass).... have you done this? Also, where are you calling the NSLog statement from? – bandejapaisa Sep 16 '13 at 13:15
Called from viewDidLoad. Yes, I also tried it w/o @sythesize and self.string2pass, but also not working... – Lorenz Sep 16 '13 at 13:19
I don't use story boards, so I'm not too sure on the lifecycle - is viewDidLoad called before you have set the variable? What if you log from viewWillAppear? – bandejapaisa Sep 16 '13 at 13:22

score 0 · Answer 2 · answered Sep 16 '13 at 12:48

0

Use self.string2pass in NSLog. When we use self. to access a property then the getter/setter is called.

answered Sep 16 '13 at 12:48

Puneet Sharma

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please give the reason for downvoting? – Puneet Sharma Sep 16 '13 at 12:53
...it wasn't me... however, I think you were down voted because your answer hides the real problem that there are 2 variables, which could lead to more bugs/confusion later down the line. – bandejapaisa Sep 16 '13 at 12:56
Yeah I agree that it does not include the whole scenario but it is not a wrong answer. Anyways you have answered it completely above so it does not make any sense to repeat those things again. – Puneet Sharma Sep 16 '13 at 12:58
1

Technically, you are correct. I don't think it deserves the down vote. – bandejapaisa Sep 16 '13 at 12:59

score 0 · Answer 3 · edited Sep 16 '13 at 13:24

First you need to add NSString property to your SecondViewController.h file:

@property (nonatomic, copy) NSString *myString;

and then in FirstViewController.m file create SecondViewController object and pass to it whatever string you want:

SecondViewController *secondViewcontroller = [[SecondViewController alloc] initWithNibName:@"ACEViewController" bundle:nil];
secondViewcontroller.myString = @"WhateverYouNeedToPass";

Log string in SecondViewController

NSLog(@"%@", self.myString);

score 0 · Answer 4 · answered Sep 16 '13 at 12:53

0

In your DetailViewController.h only you need to define this -

@property (strong, nonatomic) NSString *string2pass;

In your DetailViewController.m

@synthesize string2pass

This will work for you.

answered Sep 16 '13 at 12:53

Devel

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3
9

Still getting (null) :( – Lorenz Sep 16 '13 at 13:14

Pass NSString between two DetailViewController

4 Answers4

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