NSButton value as default in swift

Question

I am a newbie in swift using Xcode trying to write a small checklist app. After I check/uncheck the checkbox and exit the app, the state just disappears next time when I reopen it next time. I am wondering how can I save the current state of NSButton as default so that next time when I open the app, it will show up the same state when I closed it. I tried below practice:

Set default value:

@IBAction func Check1(_ sender: NSButton) {
        UserDefaults.standard.set(Check1.state, forKey:"Check1status")
    }

Read default value:

override var representedObject: Any? {
    didSet {
        Check1.state = UserDefaults.standard.bool(forKey:"Check1status")
    }
}

However I received error message:"Cannot assign value of type 'Bool' to type 'NSControl.StateValue'"

How can I fix this error? Thanks.

Check out UserDefaults. https://stackoverflow.com/q/31203241/3151675 — Tamás Sengel, Apr 12 '18 at 14:49
check this one more clear according your question. https://stackoverflow.com/questions/43429699/userdefault-to-save-button-state — MRizwan33, Apr 12 '18 at 15:01
I received error message: "Value of type 'NSButton' has no member 'isSelected'" when I tried to use SelfKey.isSelected. Should I use another member in NSButton? — Jonnce, Apr 12 '18 at 15:50
Possible duplicate of [UserDefault To Save Button State](https://stackoverflow.com/questions/43429699/userdefault-to-save-button-state) — Daij-Djan, Apr 12 '18 at 15:52
When I tried to set default value SelfKey.state = UserDefaults.standard.bool(forKey: "State") after I set: UserDefaults.standard.set(SelfKey.state, forKey:"State"), I received error: "Cannot assign value of type 'Bool' to type 'NSControl.StateValue". What should I use other than UserDefaults.standard.bool? — Jonnce, Apr 12 '18 at 18:31

Code Different · Accepted Answer · 2018-04-13T00:14:39.537

Because state is not a boolean value. In Objective-C, it's an integer. In Swift, it's a struct whose rawValue is an integer. Also, don't set the state in representedObject.didSet. Do it in viewDidLoad:

override func viewDidLoad() {
    super.viewDidLoad()

    // When your app launches for the very first time on the user computer, set it to On
    UserDefaults.standard.register(defaults: [
        "Check1Status": NSControl.StateValue.on.rawValue
    ])

    let state = NSControl.StateValue(UserDefaults.standard.integer(forKey:"Check1status"))
    check1.state = state
}

@IBAction func check1(_ sender: NSButton) {
    // Swift performs do some background magic if you type check1.state
    // Adding rawValue make it clear that you are writing an integer to the UserDefaults
    UserDefaults.standard.set(check1.state.rawValue, forKey:"Check1status")
}

NSButton value as default in swift

1 Answers1