The way to disable button using provider

Question

I'm using Provider and trying to make buttons disable without StatfulWidgets. But I can't find the way to do it.

What I did:

class CLS with ChangeNotifier {
    bool pressed = false;
    bool detect(return pressed;);
    void pressed(pressed = true;)
}

....

//StatelessWidget
ElevatedButton(
  ...
  onPressed: Provider.of<CLS>(context, listen: false).detect()
             ? null : context.read<CLS>().pressed(),
  ...
)

I know buttons are disabled when onPressed is null. So I want to make it dynamicaly, but buttons color is not changed. CLS.pressed becomes true when button is pressed.

What sohould I do?

score 2 · Accepted Answer · answered Mar 03 '22 at 06:45

You forgot to use notify listeners in your CLS class

class CLS with ChangeNotifier {
  bool _pressed = false;
  bool detect() {
    return _pressed;
  }

  void pressed() {
    _pressed = true;
    notifyListeners();
  }
}

You should also remove listen:false from your onPressed provider listener to be able to react to the changes

        ElevatedButton(
          onPressed: Provider.of<CLS>(context).detect()
              ? null
              : () => context.read<CLS>().pressed(),

score 0 · Answer 2 · answered Mar 03 '22 at 06:45

Try using below code. Refer this link for more details. https://stackoverflow.com/a/68418866/16467763

//StatelessWidget

ElevatedButton(
  ...
  onPressed: Provider.of<CLS>(context).isDetect
             ? null : context.read<CLS>().pressed(),
  ...
)

//

class CLS with ChangeNotifier {
    bool _pressed = false;
   
    bool get isDetect => _pressed;

    void pressed() {
       this._pressed  = true;
   
       Future.delayed(Duration(seconds: 0)).then((value) {
          super.notifyListeners();
       });
    }
}

The way to disable button using provider

2 Answers2