Change if statement with UISwitch - ios

Question

Hi I'm currently developing an app where you have a viewController with a UISwitch that i have got working with NSLog. My question is if you can change stuff in other viewControllers by creating a BOOL and then referring to that in the if statement? Heres some code:
UISwitch *mySwitch = [[UISwitch alloc] initWithFrame:CGRectMake(251, 111, 0, 0)];
[mySwitch addTarget:self action:#selector(changeSwitch:) forControlEvents:UIControlEventValueChanged];
[mySwitch setOnTintColor:UIColorFromRGB(0xac1f2d)];
[self.view addSubview:mySwitch];
- (void)changeSwitch:(id)sender{
if([sender isOn]){
NSLog(#"Switch is ON");
} else{
NSLog(#"Switch is OFF");
}

Answer 1

If you want to change something in another ViewController, you can do this by creating a reference to the other ViewController.
If you add public properties to the 'other' ViewController, you can change them in your if statement.

Answer 2

Say you have another VC, OtherViewController.
Create a BOOL property in it like:
#property(nonatomic) BOOL flag;
Implement the setter for the property in .m file of OtherViewController:
-(void)setFlag:(BOOL)flag {
_flag = flag;
if(_flag) { //if flag is true do something
//...........
}
else { //do anything else
//........
}
}
Now create a reference of OtherViewController instance in your first view controller, containing the switch. Say its referred by a property named other from the current view controller. Then you can trigger the required action on OtherViewController based on the switch's value from your present view controller like this:
- (void)changeSwitch:(UISwitch*)sender{
self.other.flag = sender.on;
}
This will call the setter of flag property in OtherViewController and would according to what you have written there.
Of course, the instance of OtherViewController should not be deallocated in between.

Answer 3

To expand on Stefan answer:
you would need to add property to the ViewController you want to change
so in ViewControllerA you would import the ViewControllerB header:
#import "ViewControllerB.h"
So that you can change that property in the method
- (void)changeSwitch:(id)sender{
ViewControllerB *viewcontroller = [[ViewControllerB alloc]init]];
if([sender isOn]){
viewcontroller.log = #"Switch is ON";
} else{
viewcontroller.log = #"Switch is OFF";
}
}

Answer 4

I'm interpreting your question to be asking whether you can change the state of another view controller using a switch on your existing view controller. The answer is yes.
You have a conditional to decide the state of the switch already. To make the connection you want to add a property to the view controller you are about to push. When you instantiate the new view controller, set the state of its property after checking if([mySwitch isOn]) (create an IBOutlet so you can check it at any time rather than responding to an IBAction), then push it. If you're going to get there via segue, you would check the state of the switch in prepareForSegue: instead.
Here's how you set the property in prepareForSegue:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"uniqueSegueIdentifierFromIB"])
{
// Get a reference to the DestinationViewController
DestinationViewController *destinationVC = [segue destinationViewController];
// DestinationViewController has public #property (nonatomic) BOOL configurationOption;
if([mySwitch isOn])
{
[destinationVC setConfigurationOption:YES];
}
else
{
[destinationVC setConfigurationOption:NO];
}
}
}
Check the state of the new view controller's property in viewDidLoad: to decide how you want to configure it.