CODEWITHSUNDEEP
iosobjective-cuiviewcontrollerhierarchy
tomiQrsd
tomiQrsd

Reputation: 119

IBAction not getting called from Subviews button click

So I spent my whole evening trying to solve my issue that is clicking Button located in UIViewController will not trigger IBAction.

My situation

I'm building my app using storyboard and my main ViewController is a TabBarViewController. One of the items of said TabBarViewController is, let's call it MainViewController.

Behind MainViewController there is BackgroundViewController which contains only camera preview and nothing else.

BackgroundViewController was added inside MainViewController as follows:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
BackgrondViewController *bckgController = (BackgrondViewController *)[storyboard instantiateViewControllerWithIdentifier:@"background"];

[self.view addSubview:bckgController.view];
[self.view sendSubviewToBack:bckgController.view];

Everything works so far and I'm mentioning it becouse that might be relevant.

TopController

Now I want to add another ViewController to the MainViewController, this time on top. Let's call top view controller as TopViewController.

So first I instatiate it like this:

TopViewController *topController = (TopViewController *)[storyboard instantiateViewControllerWithIdentifier:@"top"];
topController.view.backgroundColor = [UIColor clearColor];

I added clearColor because there is need for that in my app and its confirmed that this changes nothing (trust me, I tried).

Okay now I add freshly created view as follows (we are still inside MainViewController)

 [self.view addSubview:topController.view];
 [self.view bringSubviewToFront:topController.view];

And it in fact does display transparent view with just a button in the center.

The Issue

No matter what I try I cannot make the button call its IBAction method.

Known facts and what I tried

Please help me get out of this jam. Thanks!

Upvotes: 3

Views: 1016

Answers (1)

Kevin Low
Kevin Low

Reputation: 2682

Are you retaining topController by using an instance variable or property?

A simple way to do this is to create a property in your MainViewController.h file.

@interface MainViewController : UIViewController
    @property (nonatomic, strong) TopViewController *topViewController;
@end

Or at the top of your MainViewController.m file

@interface MainViewController ()
    @property (nonatomic, strong) TopViewController *topViewController;
@end

Then set the property any time after you created it.

self.topViewController = topController;

Explanation

-[UIView addSubview:] retains the view, but not the view controller. If you do not retain the view controller, then ARC will release the view controller at the end of the function. You can verify this by overriding -[TopViewController dealloc]. When you press the button, it tries to send a message to a now nil view controller.

Upvotes: 6

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