Flutter app freezes when a TextField or TextFormField is selected : <p>I have a Flutter app that is functioning properly in all respects except when I select a TextField (or TextFormField).  When I select the TextField, the cursor blinks in the TextField, but I can't type anything AND all other buttons like the floatingActionButton and the back button in the AppBar quit working. Essentially, the app appears to be frozen, but I don't get any error messages.</p>

<p>After numerous attempts to fix the problem in two different pages that contain FocusNodes and TextEditingControllers, I went back to square one by incorporating a new page with code straight from Flutter's website, but the TextField in this barebones code still locks up the app.</p>

<pre><code>import 'package:flutter/material.dart';

class EventDetailForm extends StatefulWidget {
  static const String routeName = "/events/event-detail-form";
  @override
  _EventDetailFormState createState() =&gt; _EventDetailFormState();
}

class _EventDetailFormState extends State&lt;EventDetailForm&gt; {
  final myController = TextEditingController();
  @override
  void dispose() {
    myController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Event Detail')),
      body: Padding(
          padding: const EdgeInsets.all(16),
          child: TextField(
            controller: myController,
          )),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          return showDialog(
              context: context,
              builder: (context) {
                return AlertDialog(
                  content: Text(myController.text),
                );
              });
        },
        child: Icon(Icons.text_fields),
      ),
    );
  }
}
</code></pre>

<p>Unfortunately, I am not getting any error messages.  The cursor just blinks in the TextField and everything else loses function and I have to quit and restart.  I am not sure what else I should be considering.  Does anyone have any ideas on what might be causing this?</p>
