Currently i am implementing the DatePicker where i am selecting the initial date and then passing that date to another date picker which will give me the only dates that are weekly(day after 7 days) or monthly(Day after 30 days) based on the selected date. But it seems I am not getting it I Messing it some where.

Adding a sample code for the reference.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  DateTime selectedDate = DateTime(2020, 1, 14);

  // DatePicker will call this function on every day and expect
  // a bool output. If it's true, it will draw that day as "enabled"
  // and that day will be selectable and vice versa.
  bool _predicate(DateTime day) {
    print(day);

    if ((day.isAfter(selectedDate.subtract(Duration(days: 1))) &&
        day.isBefore(selectedDate.add(Duration(days: 7))))) {
      return true;
    }


    return false;
  }

  Future<void> _selectDate(BuildContext context) async {
    final DateTime? picked = await showDatePicker(
        context: context,
        initialDate: selectedDate,
        selectableDayPredicate: _predicate,
        firstDate: DateTime(2019),
        lastDate: DateTime(2021),
        builder: (context, child) {
          return Theme(
            data: ThemeData(
                primaryColor: Colors.orangeAccent,
                disabledColor: Colors.brown,
                textTheme: TextTheme(bodyText1: TextStyle(color: Colors.blueAccent)),
                accentColor: Colors.yellow),
            child: child!,
          );
        });
    if (picked != null && picked != selectedDate)
      setState(() {
        selectedDate = picked;
      });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Text("${selectedDate.toLocal()}".split(' ')[0]),
            SizedBox(
              height: 20.0,
            ),
            RaisedButton(
              onPressed: () => _selectDate(context),
              child: Text('Select date'),
            ),
          ],
        ),
      ),
    );
  }
}

Current Result :

Can any one guide any better resource for this one or suggest if any one has worked on this one.

CodePudding user response：

  void _datePicker() {
showDatePicker(
  context: context,
  initialDate: DateTime.now(),
  firstDate: DateTime(2019),
  lastDate: DateTime.now(),
).then((value) {
  if (value == null) {
    return;
  }
  setState(() {
    _selectedDate = value;
  });
});

}

And Where ever you want to use this

              Container(
            height: 70,
            child: Row(
              children: <Widget>[
                FlatButton(
                  textColor: Theme.of(context).primaryColor,
                  onPressed: _datePicker,
                  child: Text(
                    'Choose Date',
                    style: TextStyle(fontWeight: FontWeight.bold),
                  ),
                ),
              ],
            ),
          ),

this should solve your issue SO you just need to add initial and last date.

CodePudding user response：

From my understanding, what you want is to only enable dates in interval of weekly or monthly(?) For example, your current initialDate is 14/01/2020, so it should only enable

• weekly: 21/01/2020, 28/01/2020 and so on.
• Monthly: 13/02/2020 (because 31 days for January).

  bool _predicate(DateTime day) {
    print(day);

    if (selectedDate.difference(day).inDays == 7 ||
     selectedDate.difference(day).inDays == 30) {
      return true;
    }

    return false;
  }

Please recheck if any errors cause I did not run this directly.