Flutter calling showTimePicker function results in error: The getter 'modalBarrierDismissLabel' was called on null

Question

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text("Hello Flutter"),),
        body: Column(children: [
          GestureDetector(
              onTap: () {
                showTimePicker(
                  context: context,
                  initialTime: const TimeOfDay(hour: 7, minute: 0),
                );
              },
              child: Text("22:30")
          )

Trying to add timePicker to my Flutter application like this. Tapping on the text results in error.

E/flutter (23737): [ERROR:flutter/shell/common/shell.cc(181)] Dart Error: Unhandled exception: E/flutter (23737): NoSuchMethodError: The getter 'modalBarrierDismissLabel' was called on null. E/flutter (23737): Receiver: null E/flutter (23737): Tried calling: modalBarrierDismissLabel E/flutter (23737): #0
Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:48:5) E/flutter (23737): #1 showDialog (package:flutter/src/material/dialog.dart:615:53) E/flutter (23737):

Answer 1

This is a problem because the context passed to the showTimePicker() is above the MaterialApp in the widget tree.

To fix it you need another context and you can use a Builder below MaterialApp .

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("Hello Flutter"),
        ),
        body: Builder(
          builder: (context) => Column(
            children: [
              GestureDetector(
                onTap: () {
                  showTimePicker(
                    context: context,
                    initialTime: const TimeOfDay(hour: 7, minute: 0),
                  );
                },
                child: Text("22:30"),
              )
            ],
          ),
        ),
      ),
    );
  }
}