CODEWITHSUNDEEP
iosobjective-cxcode
coder35
coder35

Reputation: 51

problems passing data through view controllers (using segues) xcode

I'm trying to create a basic app that takes info that the user puts in to display it on a second view controller.I have a button that push(deprecated) to ViewControllerTwo with a identifier that is "calButtonPressed" but then I want it to display float BAC on a label on ViewControllerTwo. The label just says nothing but it does go to the next ViewController.It also has no errors in the code. What can I do to fix this? Thanks :)

Code on ViewController.m

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    if([segue.identifier isEqualToString:@"calButtonPressed"])
    {
        ViewControllerTwo *vc2 = (ViewControllerTwo *)segue.destinationViewController;
        vc2.lblBAC.text = [[NSString alloc] initWithFormat:@"%f", BAC];
    }
}

Code on ViewController.h

@property (strong, nonatomic) IBOutlet UILabel *lblBAC;

Upvotes: 0

Views: 77

Answers (2)

iCMS
iCMS

Reputation: 499

In ViewCongtrollerTwo, add a property to hold the text until the view has been loaded. 

@interface ViewControllerTwo () 

@property (strong, nonatomic) NSString *textFromlblBAC;

@end

Use this instead in your prepareForSegue:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{

if([segue.identifier isEqualToString:@"calButtonPressed"])
{
    ViewControllerTwo *vc2 = (ViewControllerTwo *)segue.destinationViewController;
    vc2.textFromlblBAC = [[NSString alloc] initWithFormat:@"%f", BAC];
}

And then also in ViewCongtrollerTwo, copy this value into the labels text field only after the text field has been created and the view has been loaded.

- (void)viewDidLoad
{
    [super viewDidLoad];

    viewControllerTwoLabel.text = self.textFromlblBAC;
}

Upvotes: 2

Mike Taverne
Mike Taverne

Reputation: 9352

You can't set lblBAC because vc2's view has not yet loaded. Instead, declare a string property on vc2, set that in prepareForSegue, and then set lblBAC.text to that property in the viewDidLoad of vc2.

Upvotes: 1

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