# \[RESOLVIDO\] Livro Flutter Framework - Capítulo 7 - Exemplo do QR Code não roda

**URL:** <https://forum.casadocodigo.com.br/t/resolvido-livro-flutter-framework-capitulo-7-exemplo-do-qr-code-nao-roda/1735>\
**Category:** Livros\
**Created:** [Agosto 15, 2020, 12:00am UTC](https://forum.casadocodigo.com.br/t/resolvido-livro-flutter-framework-capitulo-7-exemplo-do-qr-code-nao-roda/1735 "2020-08-15T00:00:40Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![gazal](https://avatars.discourse-cdn.com/v4/letter/g/c5a1d2/32.png) [@gazal](https://forum.casadocodigo.com.br/u/gazal)\
**Post date:** [Agosto 15, 2020, 12:00am UTC](https://forum.casadocodigo.com.br/t/resolvido-livro-flutter-framework-capitulo-7-exemplo-do-qr-code-nao-roda/1735/1 "2020-08-15T00:00:40Z")

</div>

Estou lendo o livro **Iniciando com Flutter Framework - Desenvolva aplicações móveis no Dart Side!** e acompanhando os exemplos, mas ao chegar no Capítulo 7 - Dependências, não está rodando o exemplo.  
Estou testando usando um smartphone com Android 7.1.2. O aplicativo abre mas quando clico no botão “Ler QR Code” não acontece nada e o console não apresenta nenhum erro.

Como resolver esse problema?

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<div class="post-metadata">

**Author:** ![gazal](https://avatars.discourse-cdn.com/v4/letter/g/c5a1d2/32.png) [@gazal](https://forum.casadocodigo.com.br/u/gazal)\
**Post date:** [Agosto 15, 2020, 12:47am UTC](https://forum.casadocodigo.com.br/t/resolvido-livro-flutter-framework-capitulo-7-exemplo-do-qr-code-nao-roda/1735/2 "2020-08-15T00:47:45Z")

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Fiz o mesmo exemplo da documentação do plugin ([https://pub.dev/packages/qrcode\_reader/example](https://pub.dev/packages/qrcode_reader/example)). A câmera não abre, mas aparecem informações no console:

```
I/ViewRootImpl(28043): ViewRoot's Touch Event : ACTION_DOWN
I/ViewRootImpl(28043): ViewRoot's Touch Event : ACTION_UP
E/flutter (28043): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception:     
MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
e[38;5;244mE/flutter (28043): #0 MethodChannel._invokeMethode[39;49m
E/flutter (28043): <asynchronous suspension>
e[38;5;244mE/flutter (28043): #1 MethodChannel.invokeMethode[39;49m
e[38;5;248mE/flutter (28043): #2 QRCodeReader.scane[39;49m
e[38;5;248mE/flutter (28043): #3 _MyHomePageState.build.<anonymous closure>. <anonymous closure>e[39;49m
e[38;5;244mE/flutter (28043): #4 State.setStatee[39;49m
e[38;5;248mE/flutter (28043): #5 _MyHomePageState.build.<anonymous closure>e [39;49m
e[38;5;244mE/flutter (28043): #6 _InkResponseState._handleTape[39;49m
e[38;5;244mE/flutter (28043): #7 _InkResponseState.build.<anonymous closure>e[39;49m
e[38;5;244mE/flutter (28043): #8 GestureRecognizer.invokeCallbacke[39;49m
e[38;5;244mE/flutter (28043): #9 TapGestureRecognizer.handleTapUpe[39;49m
e[38;5;244mE/flutter (28043): #10 BaseTapGestureRecognizer._checkUpe[39;49m
e[38;5;244mE/flutter (28043): #11 BaseTapGestureRecognizer.acceptGesturee[39;49m
e[38;5;244mE/flutter (28043): #12 GestureArenaManager.sweepe[39;49m
e[38;5;244mE/flutter (28043): #13 GestureBinding.handleEvente[39;49m
e[38;5;244mE/flutter (28043): #14 GestureBinding.dispatchEvente[39;49m
e[38;5;244mE/flutter (28043): #15 GestureBinding._handlePointerEvente[39;49m
e[38;5;244mE/flutter (28043): #16 GestureBinding._flushPointerEventQueuee[39;49m
e[38;5;244mE/flutter (28043): #17 GestureBinding._handlePointerDataPackete[39;49m
e[38;5;244mE/flutter (28043): #18 _rootRunUnary (dart:async/zone.dart:1206:13)e [39;49m
e[38;5;244mE/flutter (28043): #19 _CustomZone.runUnary (dart:async/zone.dart:1100:19)e[39;49m
e[38;5;244mE/flutter (28043): #20 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)e[39;49m
e[38;5;244mE/flutter (28043): #21 _invoke1 (dart:ui/hooks.dart:267:10)e[39;49m
e[38;5;244mE/flutter (28043): #22 _dispatchPointerDataPacket (dart:ui/hooks.dart:176:5)e[39;49m
E/flutter (28043):
I/ViewRootImpl(28043): ViewRoot's Touch Event : ACTION_DOWN
I/ViewRootImpl(28043): ViewRoot's Touch Event : ACTION_UP
E/flutter (28043): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
e[38;5;244mE/flutter (28043): #0 MethodChannel._invokeMethode[39;49m
E/flutter (28043): <asynchronous suspension>
e[38;5;244mE/flutter (28043): #1 MethodChannel.invokeMethode[39;49m
e[38;5;248mE/flutter (28043): #2 QRCodeReader.scane[39;49m
e[38;5;248mE/flutter (28043): #3 _MyHomePageState.build.<anonymous closure>.<anonymous closure>e[39;49m
e[38;5;244mE/flutter (28043): #4 State.setStatee[39;49m
e[38;5;248mE/flutter (28043): #5 _MyHomePageState.build.<anonymous closure>e[39;49m
e[38;5;244mE/flutter (28043): #6 _InkResponseState._handleTape[39;49m
e[38;5;244mE/flutter (28043): #7 _InkResponseState.build.<anonymous closure>e[39;49m
e[38;5;244mE/flutter (28043): #8 GestureRecognizer.invokeCallbacke[39;49m
e[38;5;244mE/flutter (28043): #9 TapGestureRecognizer.handleTapUpe[39;49m
e[38;5;244mE/flutter (28043): #10 BaseTapGestureRecognizer._checkUpe[39;49m
e[38;5;244mE/flutter (28043): #11 BaseTapGestureRecognizer.acceptGesturee[39;49m
e[38;5;244mE/flutter (28043): #12 GestureArenaManager.sweepe[39;49m
e[38;5;244mE/flutter (28043): #13 GestureBinding.handleEvente[39;49m
e[38;5;244mE/flutter (28043): #14 GestureBinding.dispatchEvente[39;49m
e[38;5;244mE/flutter (28043): #15 GestureBinding._handlePointerEvente[39;49m
e[38;5;244mE/flutter (28043): #16 GestureBinding._flushPointerEventQueuee[39;49m
e[38;5;244mE/flutter (28043): #17 GestureBinding._handlePointerDataPackete[39;49m
e[38;5;244mE/flutter (28043): #18 _rootRunUnary (dart:async/zone.dart:1206:13)e[39;49m
e[38;5;244mE/flutter (28043): #19 _CustomZone.runUnary (dart:async/zone.dart:1100:19)e[39;49m
e[38;5;244mE/flutter (28043): #20 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)e[39;49m
e[38;5;244mE/flutter (28043): #21 _invoke1 (dart:ui/hooks.dart:267:10)e[39;49m
e[38;5;244mE/flutter (28043): #22 _dispatchPointerDataPacket (dart:ui/hooks.dart:176:5)e[39;49m
E/flutter (28043):
```

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<div class="post-metadata">

**Author:** ![gazal](https://avatars.discourse-cdn.com/v4/letter/g/c5a1d2/32.png) [@gazal](https://forum.casadocodigo.com.br/u/gazal)\
**Post date:** [Agosto 15, 2020, 6:53pm UTC](https://forum.casadocodigo.com.br/t/resolvido-livro-flutter-framework-capitulo-7-exemplo-do-qr-code-nao-roda/1735/3 "2020-08-15T18:53:53Z")

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Rodei o projeto do GitHub do livro e funcinou.

- [https://github.com/Leomhl/flutterbook\_qr\_code](https://github.com/Leomhl/flutterbook_qr_code)