dart - Flutter Share软件包导致无用的错误

Question

我正在尝试使用Flutter团队提供的Share软件包。我尝试实现该程序包，但当该方法不起作用时，我尝试直接复制并粘贴其代码，但同样出现错误。不幸的是，该错误不是很有帮助，错误的描述为“我们需要对此做更好的解释”。有任何想法吗？

Here's the package I'm using

我的代码:

FlatButton(
    child: Text(
        'Share',
        style: TextStyle(
            color: Color.fromRGBO(245, 93, 62, 1.0)),
    ),
    color: Colors.grey[100],
    onPressed: () {
        final RenderBox box = context.findRenderObject();
        Share.share('Hello this is a test',
            sharePositionOrigin:
                box.localToGlobal(Offset.zero) &
                box.size);
    },
),

错误:

flutter: The following assertion was thrown while handling a gesture:
flutter: type 'RenderSliverList' is not a subtype of type 'RenderBox'
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?template=BUG.md
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0      _EverythingState._buildEventCards.<anonymous closure> (package:loopt_in/widgets/everything.dart:175:43)
flutter: #1      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
flutter: #2      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
flutter: #3      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
flutter: #4      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)
flutter: #5      TapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:204:7)
flutter: #6      GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
flutter: #7      _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:184:20)
flutter: #8      _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:158:22)
flutter: #9      _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:138:7)
flutter: #10     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
flutter: #11     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
flutter: #12     _invoke1 (dart:ui/hooks.dart:165:13)
flutter: #13     _dispatchPointerDataPacket (dart:ui/hooks.dart:119:5)
flutter: Handler: onTap
flutter: Recognizer:
flutter:   TapGestureRecognizer#ecc56(debugOwner: GestureDetector, state: ready, won arena, finalPosition:
flutter:   Offset(196.0, 747.5), sent tap down)

更新

import 'package:flutter/material.dart';

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';
import 'package:share/share.dart';

class Everything extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return _EverythingState();
  }
}

class _EverythingState extends State<Everything> {
  Widget _buildEventCards(BuildContext context, DocumentSnapshot document) {
    var width = MediaQuery.of(context).size.width;

    return Container(
      padding: EdgeInsets.symmetric(vertical: 10.0, horizontal: 14.0),
      child: Card(
        elevation: 0.0,
        child: Column(
          children: <Widget>[
            Image.asset(
              document['image'],
              fit: BoxFit.cover,
            ),
            Container(
              padding: EdgeInsets.symmetric(vertical: 15.0, horizontal: 20.0),
              child: Column(
                children: <Widget>[
                  SizedBox(
                    height: 15.0,
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: <Widget>[
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                        children: <Widget>[
                          // Icon(document['icon']),
                        ],
                      ),
                    ],
                  ),
                  SizedBox(
                    height: 10.0,
                  ),
                  Wrap(
                    direction: Axis.horizontal,
                    alignment: WrapAlignment.start,
                    runAlignment: WrapAlignment.start,
                    children: <Widget>[
                      Chip(
                        backgroundColor: Colors.grey[100],
                        label: Text(
                          document['date'],
                        ),
                      ),
                      SizedBox(
                        width: 10.0,
                      ),
                      Chip(
                        backgroundColor: Colors.grey[100],
                        label: Text(document['source']),
                      ),
                      SizedBox(
                        width: 10.0,
                      ),
                      Chip(
                        backgroundColor: Colors.grey[100],
                        label: Text(
                          document['location'],
                        ),
                      ),
                    ],
                  ),
                  SizedBox(
                    height: 15.0,
                  ),
                  Container(
                    width: width,
                    child: Text(
                      document['title'],
                      style: TextStyle(fontSize: 24.0),
                    ),
                  ),
                  SizedBox(
                    height: 20.0,
                  ),
                  Text(document['desc']),
                  SizedBox(
                    height: 20.0,
                  ),
                  Row(
                    children: <Widget>[
                      FlatButton(
                        child: Text(
                          'More',
                          style: TextStyle(
                              color: Color.fromRGBO(118, 190, 208, 1.0)),
                        ),
                        color: Colors.grey[100],
                        onPressed: () {
                          print('webview clicked');
                          Navigator.of(context).push(
                            MaterialPageRoute(
                              builder: (context) => WebviewScaffold(
                                    url: document['url'],
                                    appBar: AppBar(
                                      title: Text(document['source']),
                                      backgroundColor: Color.fromRGBO(
                                        135,
                                        142,
                                        136,
                                        1.0,
                                      ),
                                    ),
                                  ),
                            ),
                          );
                        },
                      ),
                      SizedBox(
                        width: 15.0,
                      ),
                      FlatButton(
                        child: Text(
                          'Share',
                          style: TextStyle(
                              color: Color.fromRGBO(245, 93, 62, 1.0)),
                        ),
                        color: Colors.grey[100],
                        onPressed: () {
                          final RenderBox box = context.findRenderObject();
                          Share.share('Hello this is a test',
                                  sharePositionOrigin:
                                      box.localToGlobal(Offset.zero) &
                                          box.size);
                        },
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder(
        stream: Firestore.instance.collection('stories').snapshots(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) return const Text('Loading...');
          return ListView.builder(
            itemCount: snapshot.data.documents.length,
            itemBuilder: (context, index) =>
                _buildEventCards(context, snapshot.data.documents[index]),
          );
        });
  }

  // @override
  // void initState() {
  //   // TODO: implement initState
  //   super.initState();

  //   FirebaseAdMob.instance.initialize(appId: FirebaseAdMob.testAppId);
  //   var bannerAd = _buildBanner()..load();
  // }
}

新错误回溯

[VERBOSE-2:shell.cc(184)] Dart Error: Unhandled exception:
MissingPluginException(No implementation found for method share on channel plugins.flutter.io/share)
#0      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:291:7)
<asynchronous suspension>
#1      Share.share (package:share/share.dart:44:20)
#2      ShareButton.build.<anonymous closure> (package:loopt_in/widgets/everything.dart:220:17)
#3      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
#4      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
#5      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
#6      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)

Answer 1

这行的问题

RenderBox box = context.findRenderObject();

右侧返回RenderSliv​​erList，并将其分配给RenderBox，以说明为什么存在不匹配类型。

您到底想分享什么？所以我可以帮忙

编辑:

您需要将共享按钮提取到其自己的小部件中。尝试下面的完整代码。有用。

  import 'package:flutter/material.dart';
  import 'package:cloud_firestore/cloud_firestore.dart';
  import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';
  import 'package:share/share.dart';

  class Everything extends StatefulWidget {
    @override
    State<StatefulWidget> createState() {
      // TODO: implement createState
      return _EverythingState();
    }
  }

  class _EverythingState extends State<Everything> {
    Widget _buildEventCards(BuildContext context, DocumentSnapshot document) {
      var width = MediaQuery.of(context).size.width;

      return Container(
        padding: EdgeInsets.symmetric(vertical: 10.0, horizontal: 14.0),
        child: Card(
          elevation: 0.0,
          child: Column(
            children: <Widget>[
              Image.asset(
                document['image'],
                fit: BoxFit.cover,
              ),
              Container(
                padding: EdgeInsets.symmetric(vertical: 15.0, horizontal: 20.0),
                child: Column(
                  children: <Widget>[
                    SizedBox(
                      height: 15.0,
                    ),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: <Widget>[
                        Row(
                          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                          children: <Widget>[
                            // Icon(document['icon']),
                          ],
                        ),
                      ],
                    ),
                    SizedBox(
                      height: 10.0,
                    ),
                    Wrap(
                      direction: Axis.horizontal,
                      alignment: WrapAlignment.start,
                      runAlignment: WrapAlignment.start,
                      children: <Widget>[
                        Chip(
                          backgroundColor: Colors.grey[100],
                          label: Text(
                            document['date'],
                          ),
                        ),
                        SizedBox(
                          width: 10.0,
                        ),
                        Chip(
                          backgroundColor: Colors.grey[100],
                          label: Text(document['source']),
                        ),
                        SizedBox(
                          width: 10.0,
                        ),
                        Chip(
                          backgroundColor: Colors.grey[100],
                          label: Text(
                            document['location'],
                          ),
                        ),
                      ],
                    ),
                    SizedBox(
                      height: 15.0,
                    ),
                    Container(
                      width: width,
                      child: Text(
                        document['title'],
                        style: TextStyle(fontSize: 24.0),
                      ),
                    ),
                    SizedBox(
                      height: 20.0,
                    ),
                    Text(document['desc']),
                    SizedBox(
                      height: 20.0,
                    ),
                    Row(
                      children: <Widget>[
                        FlatButton(
                          child: Text(
                            'More',
                            style: TextStyle(
                                color: Color.fromRGBO(118, 190, 208, 1.0)),
                          ),
                          color: Colors.grey[100],
                          onPressed: () {
                            print('webview clicked');
                            Navigator.of(context).push(
                              MaterialPageRoute(
                                builder: (context) => WebviewScaffold(
                                  url: document['url'],
                                  appBar: AppBar(
                                    title: Text(document['source']),
                                    backgroundColor: Color.fromRGBO(
                                      135,
                                      142,
                                      136,
                                      1.0,
                                    ),
                                  ),
                                ),
                              ),
                            );
                          },
                        ),
                        SizedBox(
                          width: 15.0,
                        ),
                        new MyButton(),
                      ],
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      );
    }

    @override
    Widget build(BuildContext context) {
      return StreamBuilder(
          stream: Firestore.instance.collection('stories').snapshots(),
          builder: (context, snapshot) {
            if (!snapshot.hasData) return const Text('Loading...');
            return ListView.builder(
              itemCount: snapshot.data.documents.length,
              itemBuilder: (context, index) =>
                  _buildEventCards(context, snapshot.data.documents[index]),
            );
          });
    }

  // @override
  // void initState() {
  //   // TODO: implement initState
  //   super.initState();

  //   FirebaseAdMob.instance.initialize(appId: FirebaseAdMob.testAppId);
  //   var bannerAd = _buildBanner()..load();
  // }
  }

  class MyButton extends StatelessWidget {
    const MyButton({
      Key key,
    }) : super(key: key);

    @override
    Widget build(BuildContext context) {
      return FlatButton(
        child: Text(
          'Share',
          style: TextStyle(
              color: Color.fromRGBO(245, 93, 62, 1.0)),
        ),
        color: Colors.grey[100],
        onPressed: () {
          final RenderBox box = context.findRenderObject();
          Share.share('Hello this is a test',
              sharePositionOrigin:
              box.localToGlobal(Offset.zero) &
              box.size);
        },
      );
    }
  }