Flutter视频播放插件chewie_video_player的使用

安装

首先，在你的 pubspec.yaml 文件中添加 video_player 作为依赖项。

iOS

如果你需要通过 http（而不是 https）访问视频，请确保在你的应用的 Info.plist 文件中添加适当的 NSAppTransportSecurity 权限。该文件位于 <项目根目录>/ios/Runner/Info.plist。参见 Apple 的文档 获取更多详细信息。

Android

如果你使用的是网络视频，请确保在你的 AndroidManifest.xml 文件中添加以下权限：

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

该文件位于 <项目根目录>/android/app/src/main/AndroidManifest.xml。

Web

注意： Web 平台不支持 dart:io，因此避免使用 VideoPlayerController.file 构造函数。尝试使用该构造函数会抛出 UnimplementedError。

不同浏览器可能有不同的视频播放能力（支持格式、自动播放等）。请参阅 video_player_web 包 获取更多相关信息。

VideoPlayerOptions.mixWithOthers 选项在 Web 上目前无法实现。如果你在 Web 上使用此选项，它将被静默忽略。

支持的格式

• 在 iOS 上，后台播放器是 AVPlayer。支持的格式取决于 iOS 的版本。你可以查询 AVURLAsset 类的 audiovisualTypes 属性来获取支持的音频视频格式。
• 在 Android 上，后台播放器是 ExoPlayer。请参阅 这里 获取支持的格式列表。
• 在 Web 上，可用格式取决于用户的浏览器（供应商和版本）。请参阅 video_player_web 包 获取更多特定信息。

示例

以下是一个使用 video_player 插件的简单示例：

import 'package:video_player/video_player.dart';
import 'package:flutter/material.dart';

void main() => runApp(VideoApp());

class VideoApp extends StatefulWidget {
  [@override](/user/override)
  _VideoAppState createState() => _VideoAppState();
}

class _VideoAppState extends State<VideoApp> {
  VideoPlayerController _controller;

  [@override](/user/override)
  void initState() {
    super.initState();
    _controller = VideoPlayerController.network(
        'https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4')
      ..initialize().then((_) {
        // 确保在视频初始化后显示第一帧，即使播放按钮尚未按下。
        setState(() {});
      });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Video Demo',
      home: Scaffold(
        body: Center(
          child: _controller.value.isInitialized
              ? AspectRatio(
                  aspectRatio: _controller.value.aspectRatio,
                  child: VideoPlayer(_controller),
                )
              : Container(),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            setState(() {
              _controller.value.isPlaying
                  ? _controller.pause()
                  : _controller.play();
            });
          },
          child: Icon(
            _controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
          ),
        ),
      ),
    );
  }

  [@override](/user/override)
  void dispose() {
    super.dispose();
    _controller.dispose();
  }
}

使用方法

以下是使用 video_player 插件的更详细的用法信息。

播放速度

你可以在 _controller（VideoPlayerController 的实例）上调用 setPlaybackSpeed 方法设置播放速度。setPlaybackSpeed 接受一个 double 类型的速度值，表示视频的播放速率。

例如，当给定值为 2.0 时，视频将以两倍于正常播放速度的速度播放。

要了解播放速度的限制，请参阅 setPlaybackSpeed 方法文档。

此外，请参阅示例应用程序以获取播放速度实现的示例。

示例代码

以下是一个完整的示例代码，展示了如何在一个应用中使用多个视频播放器：

import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';

void main() {
  runApp(
    MaterialApp(
      home: _App(),
    ),
  );
}

class _App extends StatelessWidget {
  [@override](/user/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](/user/override)
  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        const _ExampleCard(title: 'Item a'),
        const _ExampleCard(title: 'Item b'),
        const _ExampleCard(title: 'Item c'),
        const _ExampleCard(title: 'Item d'),
        const _ExampleCard(title: 'Item e'),
        const _ExampleCard(title: 'Item f'),
        const _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/flutter-mark-square-64.png'),
                  ]),
            ],
          ),
        ])),
        const _ExampleCard(title: 'Item h'),
        const _ExampleCard(title: 'Item i'),
        const _ExampleCard(title: 'Item j'),
        const _ExampleCard(title: 'Item k'),
        const _ExampleCard(title: 'Item l'),
      ],
    );
  }
}

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

  final String title;

  [@override](/user/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](/user/override)
  _ButterFlyAssetVideoState createState() => _ButterFlyAssetVideoState();
}

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

  [@override](/user/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](/user/override)
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  [@override](/user/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](/user/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](/user/override)
  void initState() {
    super.initState();
    _controller = VideoPlayerController.network(
      'https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4',
      closedCaptionFile: _loadCaptions(),
      videoPlayerOptions: VideoPlayerOptions(mixWithOthers: true),
    );

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

  [@override](/user/override)
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  [@override](/user/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 List<Duration> _exampleCaptionOffsets = [
    Duration(seconds: -10),
    Duration(seconds: -3),
    Duration(seconds: -1, milliseconds: -500),
    Duration(milliseconds: -250),
    Duration(milliseconds: 0),
    Duration(milliseconds: 250),
    Duration(seconds: 1, milliseconds: 500),
    Duration(seconds: 3),
    Duration(seconds: 10),
  ];
  static const List<double> _examplePlaybackRates = [
    0.25,
    0.5,
    1.0,
    1.5,
    2.0,
    3.0,
    5.0,
    10.0,
  ];

  final VideoPlayerController controller;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        AnimatedSwitcher(
          duration: const Duration(milliseconds: 50),
          reverseDuration: const Duration(milliseconds: 200),
          child: controller.value.isPlaying
              ? const SizedBox.shrink()
              : Container(
                  color: Colors.black26,
                  child: const Center(
                    child: Icon(
                      Icons.play_arrow,
                      color: Colors.white,
                      size: 100.0,
                      semanticLabel: 'Play',
                    ),
                  ),
                ),
        ),
        GestureDetector(
          onTap: () {
            controller.value.isPlaying ? controller.pause() : controller.play();
          },
        ),
        Align(
          alignment: Alignment.topLeft,
          child: PopupMenuButton<Duration>(
            initialValue: controller.value.captionOffset,
            tooltip: 'Caption Offset',
            onSelected: (Duration delay) {
              controller.setCaptionOffset(delay);
            },
            itemBuilder: (BuildContext context) {
              return <PopupMenuItem<Duration>>[
                for (final Duration offsetDuration in _exampleCaptionOffsets)
                  PopupMenuItem<Duration>(
                    value: offsetDuration,
                    child: Text('${offsetDuration.inMilliseconds}ms'),
                  )
              ];
            },
            child: Padding(
              padding: const EdgeInsets.symmetric(
                // 使用较少的垂直填充，因为文本在水平方向上也较长，
                // 所以感觉需要更多的水平空间（匹配视频的宽高比）。
                vertical: 12,
                horizontal: 16,
              ),
              child: Text('${controller.value.captionOffset.inMilliseconds}ms'),
            ),
          ),
        ),
        Align(
          alignment: Alignment.topRight,
          child: PopupMenuButton<double>(
            initialValue: controller.value.playbackSpeed,
            tooltip: 'Playback speed',
            onSelected: (double speed) {
              controller.setPlaybackSpeed(speed);
            },
            itemBuilder: (BuildContext context) {
              return <PopupMenuItem<double>>[
                for (final double speed in _examplePlaybackRates)
                  PopupMenuItem<double>(
                    value: speed,
                    child: Text('${speed}x'),
                  )
              ];
            },
            child: Padding(
              padding: const EdgeInsets.symmetric(
                // 使用较少的垂直填充，因为文本在水平方向上也较长，
                // 所以感觉需要更多的水平空间（匹配视频的宽高比）。
                vertical: 12,
                horizontal: 16,
              ),
              child: Text('${controller.value.playbackSpeed}x'),
            ),
          ),
        ),
      ],
    );
  }
}

class _PlayerVideoAndPopPage extends StatefulWidget {
  [@override](/user/override)
  _PlayerVideoAndPopPageState createState() => _PlayerVideoAndPopPageState();
}

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

  [@override](/user/override)
  void initState() {
    super.initState();

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

  [@override](/user/override)
  void dispose() {
    _videoPlayerController.dispose();
    super.dispose();
  }

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

  [@override](/user/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 ?? false) {
              return AspectRatio(
                aspectRatio: _videoPlayerController.value.aspectRatio,
                child: VideoPlayer(_videoPlayerController),
              );
            } else {
              return const Text('waiting for video to load');
            }
          },
        ),
      ),
    );
  }
}