Xcode 6 - How to hide textfield in one viewcontroller from af switch in another viewcontroller

Question

I have a view controller (firstViewController) with a switch button. The switch button should show / hide a text field in the secondViewController. How can I do it?

Answer 1

Your app should be structured according to the Model-View-Controller design pattern. You need to do this:

• Add a BOOL hideText variable to your model class
• Set model.hideText to the value of the switch in the switch event handler
• Check model.hideText in the viewWillAppear handler of the view that has the text field
• If model.hideText is set, hide the text field; otherwise, show it

Answer 2

Very Simple it is.You just have to use delegate design pattern.Go through this link delegation.

In your code you have to do something like this. I suppose your switch is in secondViewCOntroller and you have to make textField hide on SwitchON in FirstViewController

Step 1) Create Protocol in second View controller like this and create property of that delegate.Pass the value of your switch in switchButtonPressed Method and call that delegate method there.

@protocol secondViewControllerDelegate <NSObject>

-(void)switchButtonPressedOn:(BOOL)switchOn;

@end

@interface secondViewController : UIViewController
@property (weak, nonatomic) IBOutlet UISwitch *switchOutlet;
@property(weak,nonatomic)id<secondViewControllerDelegate>delegate;
- (IBAction)switchButtonPressed:(id)sender;

@end

In switchButtonPressed,

- (IBAction)switchButtonPressed:(id)sender {
if(self.switchOutlet.on==YES)

[self.delegate switchButtonPressedOn:YES];

}

Step 2) In FirstViewController,

  #import "swiftViewController.h"

@interface ViewController :   UIViewController<secondViewControllerDelegate,UITextFieldDelegate>
@property (weak, nonatomic) IBOutlet UITextField *textField;
@property BOOL mySwitchState;

@end

Step 3) set delegate=self in prepareForSegue method

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    secondViewController *destViewController = segue.destinationViewController;
destViewController.delegate = self;
}
-(void)switchButtonPressedOn:(BOOL)switchOn{
NSLog(@"Method Called");

if (switchOn==YES) {
self.textField.hidden=YES;
}else{
    self.textField.hidden=NO;
    }
}

If you wanted to hide textField in nextViewController then pass the switchState to nextViewController in prepareForSegueMethod,

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
thirdViewController *thirdVC=segue.destinationViewController;
if (self.switchOutlet.on==YES) {
thirdVC.isSomethingEnabled=YES;    
         }

   }

and in nextViewController, in viewDidLoad, hide your textField.

    if (self.isSomethingEnabled==YES) {
    self.textField.hidden=YES;
}

Working perfectly. This is very important concept in iOS. Go through the above link.