Set UILabel from another view controller swift

Question

I have a segmented control in a SettingsController.

The segmented control can display temperature in Celsius or Fahrenheit.

I have a mainViewController where I have the temperature label which displays current temperature in celsius.

On click of the segmented control I want to convert the temperature to appropriate unit and display it in the mainViewController.

@IBOutlet weak var temperatureUnitSegmentedControl: UISegmentedControl!
var mainViewController : MainViewController?

@IBAction func temperatureSegmentedControlListener(sender: UISegmentedControl) {

        switch temperatureUnitSegmentedControl.selectedSegmentIndex
        {
        case 0:
            showTemperatureInCelsius()
        case 1:
            showTemperatureInFahrenheit()
        default:
            break;
        }
    }
    func showTemperatureInCelsius(){
        mainViewController?.setTempInCelsius()

    }
    func showTemperatureInFahrenheit(){
            mainViewController?.setTempInFahrenheit()
    }

In mainViewController I want to do the conversions and update the temperature label

func setTempInCelsius(){
        temperatureLabel.text = "In Celsius"
        log?.debug("Temperature Celsius\(batteryTemperatureLabel.text)")
    }

    func setTempInFahrenheit(){
        temperatureLabel.text = "In Fahrenheit"
        log?.debug("Temperature Fahrenheit\(batteryTemperatureLabel.text)")
    }

This code does not hit the functions in the mainViewController and value of the label does not get updated.

Any help will be appreciated. Thank you

For starters: Where do you set the variable `mainViewController`? Also, I assume the first code block you show is in that `SettingsController`? My guess would be that you simply never set the variable to the controller you want. Oh, and if that's the parent, don't forget to make the var `weak`, or you'll run into a retain cycle. — Gero, Oct 06 '16 at 07:54
Check the link it will solve your problem http://stackoverflow.com/questions/5210535/passing-data-between-view-controllers — Joe, Oct 06 '16 at 07:57

score 0 · Answer 1 · edited May 23 '17 at 11:48

0

You can use delegates or protocol. click here

if you have to update views then you can use nsnotificationcenter Click here

edited May 23 '17 at 11:48

Community

1
1

answered Oct 06 '16 at 08:01

Ranjana Dangol

1,319
2
13
24

You should add some code too, because links might break in future, or post it as a comment. :) – Bista Oct 06 '16 at 09:24

score 0 · Answer 2 · answered Oct 06 '16 at 08:52

0

Yoa can simply send action to your destination view controller to set the values like UIApplication.sharedApplication().sendAction("setTempInCelsious", to: nil, from: nil, forEvent: nil)

Hope this helps.

answered Oct 06 '16 at 08:52

Sachin Amrale

277
1
9

Set UILabel from another view controller swift

2 Answers2