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@Sfshaza Sfshaza/main.dart
Created Feb 24, 2018

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Step 6: Flutter Get Started codelab
// Step 6: Navigate to a new route
import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Startup Name Generator',
home: new RandomWords(),
);
}
}
class RandomWords extends StatefulWidget {
@override
createState() => new RandomWordsState();
}
class RandomWordsState extends State<RandomWords> {
final _suggestions = <WordPair>[];
final _saved = new Set<WordPair>();
final _biggerFont = const TextStyle(fontSize: 18.0);
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Startup Name Generator'),
actions: <Widget>[
new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved)
],
),
body: _buildSuggestions(),
);
}
Widget _buildSuggestions() {
return new ListView.builder(
padding: const EdgeInsets.all(16.0),
itemBuilder: (context, i) {
if (i.isOdd) return new Divider();
final index = i ~/ 2;
if (index >= _suggestions.length) {
_suggestions.addAll(generateWordPairs().take(10));
}
return _buildRow(_suggestions[index]);
},
);
}
Widget _buildRow(WordPair pair) {
final alreadySaved = _saved.contains(pair);
return new ListTile(
title: new Text(
pair.asPascalCase,
style: _biggerFont,
),
trailing: new Icon(
alreadySaved ? Icons.favorite : Icons.favorite_border,
color: alreadySaved ? Colors.red : null,
),
onTap: () {
setState(
() {
if (alreadySaved) {
_saved.remove(pair);
} else {
_saved.add(pair);
}
},
);
},
);
}
void _pushSaved() {
Navigator.of(context).push(
new MaterialPageRoute(
builder: (context) {
final tiles = _saved.map(
(pair) {
return new ListTile(
title: new Text(
pair.asPascalCase,
style: _biggerFont,
),
);
},
);
final divided = ListTile
.divideTiles(
context: context,
tiles: tiles,
)
.toList();
return new Scaffold(
appBar: new AppBar(
title: new Text('Saved Suggestions'),
),
body: new ListView(children: divided),
);
},
),
);
}
}
@kilroyjones

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kilroyjones commented Mar 4, 2018

I was going through the tutorial and got to this step and was thinking I did something wrong, but then I copy pasted this in and got the error below.

I/flutter (10902): #101    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:621:20)
I/flutter (10902): #102    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
I/flutter (10902): #103    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter (10902): #104    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter (10902): #105    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:751:7)
I/flutter (10902): #107    _Timer._runTimers (dart:isolate-patch/dart:isolate/timer_impl.dart:382)
I/flutter (10902): #108    _Timer._handleMessage (dart:isolate-patch/dart:isolate/timer_impl.dart:416)
I/flutter (10902): #109    _RawReceivePortImpl._handleMessage (dart:isolate-patch/dart:isolate/isolate_patch.dart:165)
I/flutter (10902): (elided one frame from package dart:async-patch)
I/flutter (10902): 
@Depado

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Depado commented Mar 28, 2018

Facing the same issue as @kilroyjones

@Goldstrike

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Goldstrike commented May 14, 2018

No problem from my side.

@huochezaodian

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huochezaodian commented Sep 21, 2018

I was going through the tutorial and got to this step and was thinking I did something wrong, but then I copy pasted this in and got the error below.

I/flutter (10902): #101    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:621:20)
I/flutter (10902): #102    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
I/flutter (10902): #103    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter (10902): #104    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter (10902): #105    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:751:7)
I/flutter (10902): #107    _Timer._runTimers (dart:isolate-patch/dart:isolate/timer_impl.dart:382)
I/flutter (10902): #108    _Timer._handleMessage (dart:isolate-patch/dart:isolate/timer_impl.dart:416)
I/flutter (10902): #109    _RawReceivePortImpl._handleMessage (dart:isolate-patch/dart:isolate/isolate_patch.dart:165)
I/flutter (10902): (elided one frame from package dart:async-patch)
I/flutter (10902): 

restart application

@zhangdaren

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zhangdaren commented Oct 8, 2018

flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building TickerMode(mode: disabled):
flutter: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 1732 pos 12:
flutter: '_elements.contains(element)': is not true.
flutter:
flutter: Either the assertion indicates an error in the framework itself, or we should provide substantially
flutter: more information in this error message to help you determine and fix the underlying cause.
flutter: In either case, please report this assertion by filing a bug on GitHub:
flutter: https://github.com/flutter/flutter/issues/new

....

flutter: #101 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2255:33)
flutter: #102 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:653:20)
flutter: #103 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
flutter: #104 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
flutter: #105 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
flutter: #106 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame. (package:flutter/src/scheduler/binding.dart:751:7)
flutter: #108 _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
flutter: #109 _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
flutter: #110 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
flutter: (elided 3 frames from class _AssertionError and package dart:async)
flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════

restart application is ok.

@asd8855

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asd8855 commented Oct 24, 2018

Formatting code that has a problem

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