Dart tilida 'holat' tushunchasini tushuntirib berishingiz mumkinmi va u qanday ishlatiladi?

Dartda "state" tushunchasi, widget yoki ilovaning holatiga taalluqlidir — bu vaqt o'tishi bilan o'zgarishi mumkin bo'lgan va UI ko'rsatishiga ta'sir qiladigan ma'lumotlar.

Flutterda ikkita asosiy widget turi mavjud: StatelessWidget (holatsiz) va StatefulWidget (hol bilan). StatefulWidget holatini State ob'ekti ichida saqlaydi, u o'zgarishi mumkin va widgetning qayta chizilishini chaqiradi.

Masalan, tugmani bosish bilan oshadigan hisoblagich, hozirgi qiymatini holatda saqlaydi:

class CounterWidget extends StatefulWidget {
  @override
  _CounterWidgetState createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State<CounterWidget> {
  int _count = 0;

  void _increment() {
    setState(() {
      _count++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Count: \\$_count'),
        ElevatedButton(onPressed: _increment, child: Text('Increment')),
      ],
    );
  }
}

Shu bilan, "state" — bu widget qanday ko'rinishda va qanday harakat qilishda belgilovchi ma'lumotlar bo'lib, u o'zgarganda UI yangilanadi.