Flutter Video Plugin 无法处理异常“未处理的异常：PlatformException（通道错误，无法在通道上建立连接。”

Question

我正在尝试播放从 Firebase 存储下载的视频，但是当我播放视频时，我收到了这个错误。 你能告诉我如何改进它吗？

环境

flutter 2.5.1 
dart 2.14.2
video_player 2.2.5

错误

E/flutter (19565): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: PlatformException(channel-error, Unable to establish connection on channel., null, null)
E/flutter (19565): #0      VideoPlayerApi.create (package:video_player_platform_interface/messages.dart:181:7)
E/flutter (19565): <asynchronous suspension>
E/flutter (19565): #1      MethodChannelVideoPlayer.create (package:video_player_platform_interface/method_channel_video_player.dart:50:31)
E/flutter (19565): <asynchronous suspension>
E/flutter (19565): #2      VideoPlayerController.initialize (package:video_player/video_player.dart:329:19)
E/flutter (19565): <asynchronous suspension>
E/flutter (19565): 

代码如下。这几乎是video_player 的官方示例 我只关注 BumbleBeeRemoteVideo，因为我有兴趣从 Firebase 存储中播放视频。

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

/// An example of using the plugin, controlling lifecycle and playback of the
/// video.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';
import 'package:firebase_storage/firebase_storage.dart' as firebase_storage;

class VideoPlayPage extends StatefulWidget {

  @override
  _VideoPlayPageState createState() => _VideoPlayPageState();
}

class _VideoPlayPageState extends State<VideoPlayPage> {

  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      length: 3,
      child: Scaffold(
        key: const ValueKey<String>('home_page'),
        appBar: AppBar(
          title: const Text('Video player example'),
          actions: <Widget>[
            IconButton(
              key: const ValueKey<String>('push_tab'),
              icon: const Icon(Icons.navigation),
              onPressed: () {
                Navigator.push<_PlayerVideoAndPopPage>(
                  context,
                  MaterialPageRoute<_PlayerVideoAndPopPage>(
                    builder: (BuildContext context) => _PlayerVideoAndPopPage(),
                  ),
                );
              },
            )
          ],
          bottom: const TabBar(
            isScrollable: true,
            tabs: <Widget>[
              Tab(
                icon: Icon(Icons.cloud),
                text: "Remote",
              ),
              Tab(icon: Icon(Icons.insert_drive_file), text: "Asset"),
              Tab(icon: Icon(Icons.list), text: "List example"),
            ],
          ),
        ),
        body: TabBarView(
          children: <Widget>[
            _BumbleBeeRemoteVideo(),
            _ButterFlyAssetVideo(),
            _ButterFlyAssetVideoInList(),
          ],
        ),
      ),
    );
  }
}

class _ButterFlyAssetVideoInList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        _ExampleCard(title: "Item a"),
        _ExampleCard(title: "Item b"),
        _ExampleCard(title: "Item c"),
        _ExampleCard(title: "Item d"),
        _ExampleCard(title: "Item e"),
        _ExampleCard(title: "Item f"),
        _ExampleCard(title: "Item g"),
        Card(
            child: Column(children: <Widget>[
              Column(
                children: <Widget>[
                  const ListTile(
                    leading: Icon(Icons.cake),
                    title: Text("Video video"),
                  ),
                  Stack(
                      alignment: FractionalOffset.bottomRight +
                          const FractionalOffset(-0.1, -0.1),
                      children: <Widget>[
                        _ButterFlyAssetVideo(),
                        Image.asset('assets/google.png'),
                      ]),
                ],
              ),
            ])),
        _ExampleCard(title: "Item h"),
        _ExampleCard(title: "Item i"),
        _ExampleCard(title: "Item j"),
        _ExampleCard(title: "Item k"),
        _ExampleCard(title: "Item l"),
      ],
    );
  }
}

/// A filler card to show the video in a list of scrolling contents.
class _ExampleCard extends StatelessWidget {
  const _ExampleCard({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          ListTile(
            leading: const Icon(Icons.airline_seat_flat_angled),
            title: Text(title),
          ),
          ButtonBar(
            children: <Widget>[
              TextButton(
                child: const Text('BUY TICKETS'),
                onPressed: () {
                  /* ... */
                },
              ),
              TextButton(
                child: const Text('SELL TICKETS'),
                onPressed: () {
                  /* ... */
                },
              ),
            ],
          ),
        ],
      ),
    );
  }
}

class _ButterFlyAssetVideo extends StatefulWidget {
  @override
  _ButterFlyAssetVideoState createState() => _ButterFlyAssetVideoState();
}

class _ButterFlyAssetVideoState extends State<_ButterFlyAssetVideo> {
  late VideoPlayerController _controller;

  @override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.asset('assets/Butterfly-209.mp4');

    _controller.addListener(() {
      setState(() {});
    });
    _controller.setLooping(true);
    _controller.initialize().then((_) => setState(() {}));
    _controller.play();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Column(
        children: <Widget>[
          Container(
            padding: const EdgeInsets.only(top: 20.0),
          ),
          const Text('With assets mp4'),
          Container(
            padding: const EdgeInsets.all(20),
            child: AspectRatio(
              aspectRatio: _controller.value.aspectRatio,
              child: Stack(
                alignment: Alignment.bottomCenter,
                children: <Widget>[
                  VideoPlayer(_controller),
                  _ControlsOverlay(controller: _controller),
                  VideoProgressIndicator(_controller, allowScrubbing: true),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _BumbleBeeRemoteVideo extends StatefulWidget {
  @override
  _BumbleBeeRemoteVideoState createState() => _BumbleBeeRemoteVideoState();
}

class _BumbleBeeRemoteVideoState extends State<_BumbleBeeRemoteVideo> {
  late VideoPlayerController _controller;

  Future<ClosedCaptionFile> _loadCaptions() async {
    final String fileContents = await DefaultAssetBundle.of(context)
        .loadString('assets/bumble_bee_captions.vtt');
    return WebVTTCaptionFile(
        fileContents); // For vtt files, use WebVTTCaptionFile
  }

  @override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.network(
      "MYURL OF FIRESTORE STORAGE",
      //closedCaptionFile: _loadCaptions(),
      //videoPlayerOptions: VideoPlayerOptions(mixWithOthers: true),
    );

    _controller.addListener(() {
      setState(() {});
    });
    _controller.setLooping(true);
    _controller.initialize();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Column(
        children: <Widget>[
          Container(padding: const EdgeInsets.only(top: 20.0)),
          const Text('With remote mp4'),
          Container(
            padding: const EdgeInsets.all(20),
            child: AspectRatio(
              aspectRatio: _controller.value.aspectRatio,
              child: Stack(
                alignment: Alignment.bottomCenter,
                children: <Widget>[
                  VideoPlayer(_controller),
                  ClosedCaption(text: _controller.value.caption.text),
                  _ControlsOverlay(controller: _controller),
                  VideoProgressIndicator(_controller, allowScrubbing: true),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _ControlsOverlay extends StatelessWidget {
  const _ControlsOverlay({Key? key, required this.controller})
      : super(key: key);

  static const _examplePlaybackRates = [
    0.25,
    0.5,
    1.0,
    1.5,
    2.0,
    3.0,
    5.0,
    10.0,
  ];

  final VideoPlayerController controller;

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        AnimatedSwitcher(
          duration: Duration(milliseconds: 50),
          reverseDuration: Duration(milliseconds: 200),
          child: controller.value.isPlaying
              ? SizedBox.shrink()
              : Container(
            color: Colors.black26,
            child: Center(
              child: Icon(
                Icons.play_arrow,
                color: Colors.white,
                size: 100.0,
              ),
            ),
          ),
        ),
        GestureDetector(
          onTap: () {
            controller.value.isPlaying ? controller.pause() : controller.play();
          },
        ),
        Align(
          alignment: Alignment.topRight,
          child: PopupMenuButton<double>(
            initialValue: controller.value.playbackSpeed,
            tooltip: 'Playback speed',
            onSelected: (speed) {
              controller.setPlaybackSpeed(speed);
            },
            itemBuilder: (context) {
              return [
                for (final speed in _examplePlaybackRates)
                  PopupMenuItem(
                    value: speed,
                    child: Text('${speed}x'),
                  )
              ];
            },
            child: Padding(
              padding: const EdgeInsets.symmetric(
                // Using less vertical padding as the text is also longer
                // horizontally, so it feels like it would need more spacing
                // horizontally (matching the aspect ratio of the video).
                vertical: 12,
                horizontal: 16,
              ),
              child: Text('${controller.value.playbackSpeed}x'),
            ),
          ),
        ),
      ],
    );
  }
}

class _PlayerVideoAndPopPage extends StatefulWidget {
  @override
  _PlayerVideoAndPopPageState createState() => _PlayerVideoAndPopPageState();
}

class _PlayerVideoAndPopPageState extends State<_PlayerVideoAndPopPage> {
  late VideoPlayerController _videoPlayerController;
  bool startedPlaying = false;

  @override
  void initState() {
    super.initState();

    _videoPlayerController =
        VideoPlayerController.asset('assets/Butterfly-209.mp4');
    _videoPlayerController.addListener(() {
      if (startedPlaying && !_videoPlayerController.value.isPlaying) {
        Navigator.pop(context);
      }
    });
  }

  @override
  void dispose() {
    _videoPlayerController.dispose();
    super.dispose();
  }

  Future<bool> started() async {
    await _videoPlayerController.initialize();
    await _videoPlayerController.play();
    startedPlaying = true;
    return true;
  }

  @override
  Widget build(BuildContext context) {
    return Material(
      elevation: 0,
      child: Center(
        child: FutureBuilder<bool>(
          future: started(),
          builder: (BuildContext context, AsyncSnapshot<bool> snapshot) {
            if (snapshot.data == true) {
              return AspectRatio(
                aspectRatio: _videoPlayerController.value.aspectRatio,
                child: VideoPlayer(_videoPlayerController),
              );
            } else {
              return const Text('waiting for video to load');
            }
          },
        ),
      ),
    );
  }
}

颤振医生-v

[✓] Flutter (Channel stable, 2.5.1, on macOS 11.4 20F71 darwin-x64, locale ja-JP)
    • Flutter version 2.5.1 at /Users/keihoshino/Development/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ffb2ecea52 (3 weeks ago), 2021-09-17 15:26:33 -0400
    • Engine revision b3af521a05
    • Dart version 2.14.2

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/keihoshino/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 13.0, Build version 13A233
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      ???? https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      ???? https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] Connected device (2 available)
    • sdk gphone x86 64 arm64 (mobile) • emulator-5554 • android-x64    • Android 11 (API 30) (emulator)
    • Chrome (web)                     • chrome        • web-javascript • Google Chrome 94.0.4606.71

• No issues found!

谢谢！

Answer 1

我解决了。 如果这个话题能帮助遇到同样问题的人，我很高兴。

就我而言，我在“Android/app/src/AndroidManifest.xml”中添加了这段代码 并重启安卓模拟器。

<uses-permission android:name="android.permission.INTERNET"/>

这是我的 AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.k8s.app02">
    <uses-permission android:name="android.permission.INTERNET" />
   <application
        android:label="app02"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <!-- Displays an Android View that continues showing the launch screen
                 Drawable until Flutter paints its first frame, then this splash
                 screen fades out. A splash screen is useful to avoid any visual
                 gap between the end of Android's launch screen and the painting of
                 Flutter's first frame. -->
            <meta-data
              android:name="io.flutter.embedding.android.SplashScreenDrawable"
              android:resource="@drawable/launch_background"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
</manifest>

在Readme of Video Player中有描述

谢谢！