@ Coding24h：
以下是捕获视频并播放视频的dart文件，说明：
导入自我飞镖：
我写的dart文件：
（1）’GlobalVariables.dart’-包含带有静态变量的类’gv’，
所有“页面/小部件”均可访问
（2）’LangStrings.dart’-此应用程序是多国语言，此dart文件包含
不同语言的字符串（英语，中文......）
（3）’ScreenVariables.dart’-包含所有与屏幕相关的变量，例如
方向，高度，宽度，物理高度，devicepixelratio ......
（4）“ Utilities.dart”-包含可被所有
“页面” 使用的“实用程序功能”，例如，在任何时候，任何地方显示一条祝酒消息。
InitState（）方法：在此声明并初始化相机控件。
dispose（）方法：在以下情况下，视频录制将手动停止：（1）用户单击“停止”按钮，或者（2）用户离开此页面。当用户切换到另一个应用程序或关闭手机屏幕时，视频录制也会自动停止。无论哪种情况，都应将相机控制对象放置在dispose（）中
didChangeAppLifecycleState（）方法：如果应用程序进入后台，则暂停视频播放。
funTimerVideo（）方法：一个计时器，每秒更改“滑块”的位置。（如果该用户有录制限制，则可以创建另一个计时器来停止视频录制）
funSelectVideo（）方法：从图库中选择视频。
funCameraStart（）方法：开始捕获图片以备将来预览，然后开始捕获视频
funCameraStop（）方法：停止捕获视频，如果出现以下情况，则可以调用此方法：（1）用户按下“视频录制停止”按钮，或者（2）当“ funTimerVideo”中提到的“另一个计时器”调用此方法时，超出记录限制。
程序源代码（仅适用于视频播放器和捕获页面）：
// import Flutter Dartsimport 'dart:io';import 'package:camera/camera.dart';import 'package:file_picker/file_picker.dart';import 'package:flutter/cupertino.dart';import 'package:flutter/material.dart';import 'package:font_awesome_flutter/font_awesome_flutter.dart';import 'package:intl/intl.dart';import "package:threading/threading.dart";import 'package:video_player/video_player.dart';// import Self Dartsimport 'GlobalVariables.dart';import 'LangStrings.dart';import 'ScreenVariables.dart';import 'Utilities.dart';// import Pagesimport 'BottomBar.dart';// Home Pageclass ClsHome extends StatefulWidget { @override _ClsHomeState createState() => _ClsHomeState();}class _ClsHomeState extends State<ClsHome> with WidgetsBindingObserver { AppLifecycleState _lastLifecycleState; // Declare Camera CameraController ctlCamera; // Var for Video bool bolVideoPaused = true; @override void initState() { super.initState(); print("Init State Started"); if (gv.bolHomeFirstInit) { // This page is called by navigator.push twice, do nothing on the first call gv.bolHomeFirstInit = false; } else { // Not the first time call of Init, do Init WidgetsBinding.instance.addObserver(this); try { // Try to dispose old Camera Control ctlCamera.dispose(); print("Camera Disposed 1"); } catch (err) { print("Camera Dispose Error: " + err.toString()); } try { // Declare New Camera Control ctlCamera = CameraController(gv.cameras[1], ResolutionPreset.high); ctlCamera.initialize().then((_) { if (!mounted) { ut.showToast('1:' + ls.gs('SystemErrorOpenAgain'), true); return; } setState(() {}); print('Controller Inited'); }); } catch (err) { ut.showToast('2:' + ls.gs('SystemErrorOpenAgain'), true); print("Camera Init Error: " + err.toString()); } try { gv.threadHomeVideo = new Thread(funTimerVideo); gv.threadHomeVideo.start(); print('New Video Timer Started'); } catch (err) { ut.showToast('3:' + ls.gs('SystemErrorOpenAgain'), true); print('New Video Timer Error: ' + err.toString()); } } print("Init State Ended"); } @override void dispose() async { super.dispose(); print("Dispose Started"); if (gv.bolHomeFirstDispose) { gv.bolHomeFirstDispose = false; } else { WidgetsBinding.instance.removeObserver(this); try { await funCameraStop(); ctlCamera?.dispose(); print("Camera Disposed"); } catch (err) { // print("Play Video Dispose Error 1: " + err.toString()); } try { // gv.ctlVideo?.dispose(); gv.ctlVideo.pause(); // gv.threadPageHomeVideo.abort(); // print('Thread Video Aborted'); } catch (err) { // print("Play Video Dispose Error 2: " + err.toString()); } // print('Controller dispose'); } print("Dispose Ended"); } @override void didChangeAppLifecycleState(AppLifecycleState state) { _lastLifecycleState = state; print('***** Life Cycle State: ' + _lastLifecycleState.toString() + ' *****'); if (_lastLifecycleState.toString() == 'AppLifecycleState.paused') { try { if (gv.ctlVideo.value.isPlaying) { bolVideoPaused = true; gv.ctlVideo.pause(); } setState(() {}); } catch (err) { // } } else if (_lastLifecycleState.toString() == 'AppLifecycleState.resumed') { } } // Timer to setState Video Play Position void funTimerVideo() async { while (true) { await Thread.sleep(1000); try { if (gv.ctlVideo.value.isPlaying) { gv.dblHomeVDSliderValueMS = gv.ctlVideo.value.position.inMilliseconds.toDouble(); setState(() {}); } } catch (err) { // Video Not Yet Ready, Do Nothing } } } // Select Video from External Storage funSelectVideo() async { print('Select Video Started'); String filePath = ''; filePath = await FilePicker.getFilePath(type: FileType.VIDEO); if (filePath != '') { try { // Declare Video if a video file is selected gv.ctlVideo = VideoPlayerController.file(File(filePath)) ..initialize().then((_) { // Set Video Looping gv.ctlVideo.setLooping(true); // Get Video Duration in Milliseconds gv.intHomeVDMS = gv.ctlVideo.value.duration.inMilliseconds; setState(() {}); print('Video Inited'); }); } catch (err) { print('Video Init Error: ' + err.toString()); gv.intHomeVDMS = 0; ut.showToast(ls.gs('VideoErrorUnsupport'), true); } } else { print('No Video Selected'); setState(() {}); } print('Select Video Ended'); } // The Widget that show the Video Player Widget ctnVideoPlayer() { try { double dblHeight = sv.dblBodyHeight / 1.8; print('Before Check Video Init'); if (gv.ctlVideo.value.initialized) { print('Before Check Video AspectRatio'); if (gv.ctlVideo.value.aspectRatio < 1) { dblHeight = sv.dblBodyHeight / 1.25; } print('Before Return ctnVideoPlayer'); return Column( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: <Widget>[ Container( padding: EdgeInsets.fromLTRB(0, 10, 0, 10), height: dblHeight, width: sv.dblScreenWidth, child: Center( child: AspectRatio( aspectRatio: gv.ctlVideo.value.aspectRatio, child: VideoPlayer(gv.ctlVideo), ), ), ), objVideoSlider(), ], ); print('After Return ctnVideoPlayer'); } else { print('Before Return EMPTY ctnVideoPlayer'); return Container( // color: Colors.white, height: dblHeight, width: sv.dblScreenWidth, child: Center( child: Text(ls.gs('SelectVideo')), ), ); print('After Return EMPTY ctnVideoPlayer'); } } catch (err) { print('Page Home ctnVideoPlayer() : ' + err.toString()); return Container( // color: Colors.white, height: sv.dblBodyHeight / 1.8, width: sv.dblScreenWidth, child: Center( child: Text(ls.gs('SelectVideo')), ), ); } } // function when Play or Pause clicked funPlayVideo() async { try { if (gv.ctlVideo.value.initialized) { if (gv.ctlVideo.value.isPlaying) { bolVideoPaused = true; gv.ctlVideo.pause(); // Stop Camera Recording funCameraStop(); } else { bolVideoPaused = false; gv.ctlVideo.play(); // Start Camera Recording funCameraStart(); } setState(() {}); } else { // Do Nothing } } catch (err) { // Do Nothing } } // function when Forward 15 seconds clicked funForwardVideo() async { try { if (gv.ctlVideo.value.initialized) { gv.ctlVideo.seekTo(gv.ctlVideo.value.position + Duration(seconds: 15)); setState(() {}); } else { // Do Nothing } } catch (err) { // Do Nothing } } // function when Backward 15 seconds clicked funBackwardVideo() async { try { if (gv.ctlVideo.value.initialized) { gv.ctlVideo.seekTo(gv.ctlVideo.value.position - Duration(seconds: 15)); setState(() {}); } else { // Do Nothing } } catch (err) { // Do Nothing } } // Widget to show the Slider of the playing position of Video Widget objVideoSlider() { try { if (gv.ctlVideo.value.initialized) { return Row( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: <Widget>[ Text(' '), Text(gv.ctlVideo.value.position.inHours.toString() + ":" + (gv.ctlVideo.value.position.inMinutes % 60) .toString() .padLeft(2, '0') + ":" + (gv.ctlVideo.value.position.inSeconds % 60) .toString() .padLeft(2, '0')), Expanded( child: CupertinoSlider( min: 0.0, max: gv.intHomeVDMS.toDouble(), divisions: (gv.intHomeVDMS / 1000).toInt(), value: gv.dblHomeVDSliderValueMS, onChanged: (double dblNewValue) { objVideoSliderChanged(dblNewValue); }, ), ), Text(gv.ctlVideo.value.duration.inHours.toString() + ":" + (gv.ctlVideo.value.duration.inMinutes % 60) .toString() .padLeft(2, '0') + ":" + (gv.ctlVideo.value.duration.inSeconds % 60) .toString() .padLeft(2, '0')), Text(' '), ], ); } else { return Container(); } } catch (err) { return Container(); } } // Function when Slider Changed Manually objVideoSliderChanged(dblNewValue) { gv.dblHomeVDSliderValueMS = dblNewValue; gv.ctlVideo .seekTo(Duration(milliseconds: gv.dblHomeVDSliderValueMS.toInt())); setState(() {}); } // Function Start Camera void funCameraStart() async{ // Declare File Name DateTime dtTimeStamp() => DateTime.now(); String strTimeStamp = DateFormat('yyyyMMdd_kkmmss').format(dtTimeStamp()); String strMovieFile = gv.strMoviePath + '/' + strTimeStamp + '.mp4'; gv.strImageFile = gv.strImagePath + '/' + strTimeStamp; print('File Path: ' + strMovieFile); try { await ctlCamera.takePicture(gv.strImageFile + '_01.jpg'); await ctlCamera.startVideoRecording(strMovieFile); } catch(err) { ut.showToast('4:' + ls.gs('SystemErrorOpenAgain'), true); } } // Function Stop Camera void funCameraStop() async{ try { await ctlCamera.stopVideoRecording(); } catch(err) { // ut.showToast('5:' + ls.gs('SystemErrorOpenAgain'), true); } try { await ctlCamera.takePicture(gv.strImageFile + '_02.jpg'); } catch(err) { // ut.showToast('5:' + ls.gs('SystemErrorOpenAgain'), true); } } // Main Widget @override Widget build(BuildContext context) { try { if (ctlCamera != null) { if (!ctlCamera.value.isInitialized) { print('return Container'); return Container(); } print('Before Return'); return Scaffold( appBar: PreferredSize( child: AppBar( title: Text( ls.gs('Player'), style: TextStyle(fontSize: sv.dblDefaultFontSize), ), ), preferredSize: new Size.fromHeight(sv.dblTopHeight), ), body: Column( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: <Widget>[ ctnVideoPlayer(), Stack(children: <Widget>[ Container( // color: Colors.white, height: sv.dblBodyHeight / 25, width: sv.dblScreenWidth, child: Center(child: Row( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: <Widget>[ Text(' '), AspectRatio( aspectRatio: ctlCamera.value.aspectRatio, child: CameraPreview(ctlCamera), ), ]), ), ), Container( // color: Colors.white, height: sv.dblBodyHeight / 25, width: sv.dblScreenWidth, child: Center(child: Row( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: <Widget>[ RaisedButton( onPressed: () => funSelectVideo(), child: Icon(Icons.folder_open), ), Text(' '), RaisedButton( onPressed: () => funBackwardVideo(), child: Icon(FontAwesomeIcons.angleDoubleLeft), ), Text(' '), RaisedButton( onPressed: () => funPlayVideo(), child: bolVideoPaused ? Icon(Icons.play_arrow) : Icon(Icons.pause), ), Text(' '), RaisedButton( onPressed: () => funForwardVideo(), child: Icon(FontAwesomeIcons.angleDoubleRight), ), ],), ), ), ]) ]), bottomNavigationBar: ClsBottom(), ); } else { return Container(); } } catch (err) { print('PageHome Error build: ' + err.toString()); return Container(); } }}
