Question

In my iPhone app, I have two UIViewcontroler class firstView and secondView.

From the firstView, I am presenting secondView using presentModalViewController:animated: method.

Problem is that when I am dismissing secondView, I want to hide button in firstView.

Although It does execute the code in firstView [button setHidden:YES];, but still it does not hide the button.

What could be wrong?

Answer 1

Hope you have declared property and synthesized the IBOutlet button.

Make an object of FirstViewController in SecondViewController.h and property and synthesize it.

SecondViewController.h

@interface SecondViewController {
.
.
FirstViewController *firstView;
.
.
}
@property (nonatomic,strong) FirstViewController *firstView;

@end

SecondViewController.m

@implementation SecondViewController 
.
.
@synthesize firstView;
.
.
@end

Now when you present a modal view from firstView

FirstViewController.m

-(IBAction)presentModalView {
    SecondViewController *secondView = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    secondView.firstView = self;
    [self presentModalViewController:secondView animated:YES];
}

Now in SecondViewController where you dismiss SecondViewController just add this code.

SecondViewController.m

-(IBAction)dismissModalView {
    [self.firstView.button setHidden:YES];
    [self dismissModalViewControllerAnimated:YES];
}

EDIT:

Refer to this link:

@protocol implementation in @interface in Objective-C

EDIT-2: With Protocol implementation

SecondViewController.h

@protocol SecondViewControllerDelegate <NSObject>
@required
    - (void)hideButton;
@end

@interface SecondViewController {
.
.
id <SecondViewControllerDelegate> delegate;
.
.
}
@property (retain) id delegate;

@end

SecondViewController.m

@implementation SecondViewController 
.
.
@synthesize delegate;
.
.
@end

Now when you present a modal view from firstView

FirstViewController.h

#import <UIKit/UIKit.h>

@interface FirstViewController : UIViewController<SecondViewControllerDelegate>
{
.
.
.
.
}
.
.
@end

FirstViewController.m

-(IBAction)presentModalView {
    SecondViewController *secondView = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    secondView.delegate = self;
    [self presentModalViewController:secondView animated:YES];
}

#pragma mark - SecondViewController Delegate

- (void)hideButton
  {
      [self.button setHidden:YES]; //Here button is UIButton you want to hide when second view is dismissed.
  }

Now in SecondViewController where you dismiss SecondViewController just add this code.

SecondViewController.m

-(IBAction)dismissModalView {
    [delegate hideButton];
    [self dismissModalViewControllerAnimated:YES];
}

Let me know if you need more help on this.

Hope this helps.