flutter开发实战-video_player视频播放功能及视频缓存-编程知识

flutter开发实战-video_player视频播放功能及视频缓存

最近开发过程中video_player播放视频，
在这里插入图片描述

一、引入video_player

在pubspec.yaml引入video_player

  video_player: ^2.7.0

在iOS上，video_player使用的是AVPlayer进行播放。
在Android上，video_player使用的是ExoPlayer。

二、使用前设置

2.1 在iOS中的设置

在iOS工程中info.plist添加一下设置，以便支持Https，HTTP的视频地址

<key>NSAppTransportSecurity</key>
<dict><key>NSAllowsArbitraryLoads</key><true/>
</dict>

2.2 在Android中的设置

需要在/android/app/src/main/AndroidManifest.xml文件中添加网络权限

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

三、使用前设置video_player

video_player 使用VideoPlayerController来控制播放与暂停

VideoPlayerController的初始化

_controller = VideoPlayerController.networkUrl(Uri.parse('https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4'))..initialize().then((_) {// Ensure the first frame is shown after the video is initialized, even before the play button has been pressed.setState(() {});});

显示视频Widget

Center(child: _controller.value.isInitialized? AspectRatio(aspectRatio: _controller.value.aspectRatio,child: VideoPlayer(_controller),): Container(),),

控制播放与暂停

// 播放
_controller.play();

// 暂停
_controller.pause();

完整实例代码

import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';void main() => runApp(const VideoApp());/// Stateful widget to fetch and then display video content.
class VideoApp extends StatefulWidget {const VideoApp({super.key});@override_VideoAppState createState() => _VideoAppState();
}class _VideoAppState extends State<VideoApp> {late VideoPlayerController _controller;@overridevoid initState() {super.initState();_controller = VideoPlayerController.networkUrl(Uri.parse('https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4'))..initialize().then((_) {// Ensure the first frame is shown after the video is initialized, even before the play button has been pressed.setState(() {});});}@overrideWidget 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,),),),);}@overridevoid dispose() {super.dispose();_controller.dispose();}
}

注意：video_player暂时不支持缓存，如果需要可以使用flutter_cache_manager

四缓存flutter_cache_manager下载文件

使用flutter_cache_manager代码如下

import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'dart:async';
import 'dart:typed_data';
import 'package:file/file.dart';
import 'package:flutter_suprisebox/utils/string_utils.dart';class CustomCacheManager {static const key = 'customCacheKey';static CacheManager instance = CacheManager(Config(key,stalePeriod: const Duration(days: 7),maxNrOfCacheObjects: 20,repo: JsonCacheInfoRepository(databaseName: key),fileService: HttpFileService(),),);Future<File> getSingleFile(String url, {String? key,Map<String, String>? headers,}) async {return await instance.getSingleFile(url, key: key, headers: headers);}Future<FileInfo?> getFileFromCache(String url,{bool ignoreMemCache = false}) async {String? key = StringUtils.toMD5(url);if (key != null && key.isNotEmpty) {return await instance.getFileFromCache(key, ignoreMemCache: ignoreMemCache);}return null;}Future<FileInfo> downloadFile(String url,{String? key,Map<String, String>? authHeaders,bool force = false}) async {return await instance.downloadFile(url, key: key, authHeaders: authHeaders, force: force);}Stream<FileResponse> getFileStream(String url,{String? key, Map<String, String>? headers, bool withProgress = false}) {return instance.getFileStream(url,key: key, headers: headers, withProgress: withProgress);}Future<void> removeFile(String key) async {return instance.removeFile(key);}/// Removes all files from the cacheFuture<void> emptyCache() {return instance.emptyCache();}
}

添加flutter_cache_manager后，flutter_cache_manager会先判断文件是否存在，如果不存在则下载视频文件。

使用CustomCacheManager后的视频初始化代码如下

Future<void> stuVideoPlay() async {_controller?.dispose();if (Platform.isIOS) {_controller = VideoPlayerController.network(widget.videoUrl);} else {FileInfo? fileInfo =await CustomCacheManager().getFileFromCache(widget.videoUrl);if (fileInfo == null) {fileInfo = await CustomCacheManager().downloadFile(widget.videoUrl);// if (fileInfo != null) {_controller = VideoPlayerController.file(fileInfo.file);// } else {//   _controller = VideoPlayerController.network(widget.videoUrl);// }} else {var file = await CustomCacheManager().getSingleFile(widget.videoUrl);_controller = VideoPlayerController.file(file);}}await _controller?.initialize().then((_) {// Ensure the first frame is shown after the video is initialized, even before the play button has been pressed.setState(() {});});await _controller!.setLooping(true);if (widget.autoPlay) {await _controller?.play();} else {await _controller?.pause();}}