如何检查我的widget屏幕在Android中的flutter-like-onResume中何时可见
在android中,如果某个活动在恢复时可见,则调用如何检查我的widget屏幕在Android中的flutter-like-onResume中何时可见,android,flutter,Android,Flutter,在android中,如果某个活动在恢复时可见,则调用onResume。在颤振中,恢复的等效方法是什么 我需要知道什么时候我的小部件屏幕是可见的,这样我就可以自动播放视频的基础上。当我回来时,我可能会转到另一个小部件屏幕,它会自动播放 我的方法是在didUpdateWidget中播放视频,但是每次小部件屏幕不可见时都会调用didUpdateWidget 注意:我不是在问WidgetsBindingObserver中的didchangeApplicyclestate问题,因为它为应用程序生命周期而不
onResume
。在颤振中,恢复的等效方法是什么
我需要知道什么时候我的小部件屏幕是可见的,这样我就可以自动播放视频的基础上。当我回来时,我可能会转到另一个小部件屏幕,它会自动播放
我的方法是在didUpdateWidget
中播放视频,但是每次小部件屏幕不可见时都会调用didUpdateWidget
注意:我不是在问
WidgetsBindingObserver
中的didchangeApplicyclestate
问题,因为它为应用程序生命周期而不是特定的小部件屏幕提供onResume
etc回调 这可能不是最简单的,也绝对不是完美的,但不久前我实现了类似于带有路由的事件。基本上,EventRoute
是MaterialPageRoute
的替代品,它为小部件创建、推到前台、推到后台以及弹出时提供可选回调
事件路径。飞镖:
import 'package:flutter/material.dart';
enum RouteState {
none,
created,
foreground,
background,
destroyed
}
class EventRoute<T> extends MaterialPageRoute<T> {
BuildContext _context;
RouteState _state;
Function(BuildContext) _onCreateCallback;
Function(BuildContext) _onForegroundCallback;
Function(BuildContext) _onBackgroundCallback;
Function(BuildContext) _onDestroyCallback;
EventRoute(BuildContext context, {
builder,
RouteSettings settings,
bool maintainState = true,
bool fullscreenDialog = false,
Function(BuildContext) onCreate,
Function(BuildContext) onForeground,
Function(BuildContext) onBackground,
Function(BuildContext) onDestroy
}):
_context = context,
_onCreateCallback = onCreate,
_onForegroundCallback = onForeground,
_onBackgroundCallback = onBackground,
_onDestroyCallback = onDestroy,
_state = RouteState.none,
super(builder: builder, settings: settings, maintainState: maintainState, fullscreenDialog: fullscreenDialog);
void get state => _state;
@override
void didChangeNext(Route nextRoute) {
if (nextRoute == null) {
_onForeground();
} else {
_onBackground();
}
super.didChangeNext(nextRoute);
}
@override
bool didPop(T result) {
_onDestroy();
return super.didPop(result);
}
@override
void didPopNext(Route nextRoute) {
_onForeground();
super.didPopNext(nextRoute);
}
@override
TickerFuture didPush() {
_onCreate();
return super.didPush();
}
@override
void didReplace(Route oldRoute) {
_onForeground();
super.didReplace(oldRoute);
}
void _onCreate() {
if (_state != RouteState.none || _onCreateCallback == null) {
return;
}
_onCreateCallback(_context);
}
void _onForeground() {
if (_state == RouteState.foreground) {
return;
}
_state = RouteState.foreground;
if (_onForegroundCallback != null) {
_onForegroundCallback(_context);
}
}
void _onBackground() {
if (_state == RouteState.background) {
return;
}
_state = RouteState.background;
if (_onBackgroundCallback != null) {
_onBackgroundCallback(_context);
}
}
void _onDestroy() {
if (_state == RouteState.destroyed || _onDestroyCallback == null) {
return;
}
_onDestroyCallback(_context);
}
}
尽管背景有点令人讨厌……所有的问题都解决了 从窗口小部件树(materialappwidget)的根将观察者放置在导航器上 如果您需要更多解释,请点击此链接: 我已经在我的项目中实现了它,它在@Sp4Rx下运行得非常好
// Register the RouteObserver as a navigation observer.
final RouteObserver<PageRoute> routeObserver = RouteObserver<PageRoute>();
void main() {
runApp(MaterialApp(
home: Container(),
navigatorObservers: [routeObserver],
));
}
class RouteAwareWidget extends StatefulWidget {
State<RouteAwareWidget> createState() => RouteAwareWidgetState();
}
// Implement RouteAware in a widget's state and subscribe it to
// the
// RouteObserver.
class RouteAwareWidgetState extends State<RouteAwareWidget> with RouteAware {
@override
void didChangeDependencies() {
super.didChangeDependencies();
routeObserver.subscribe(this, ModalRoute.of(context));
}
@override
void dispose() {
routeObserver.unsubscribe(this);
super.dispose();
}
@override
void didPush() {
// Route was pushed onto navigator and is now topmost route.
}
@override
void didPopNext() {
// Covering route was popped off the navigator.
}
@override
Widget build(BuildContext context) => Container();
}
//将RouteObserver注册为导航观察员。
最终RouteObserver RouteObserver=RouteObserver();
void main(){
runApp(材料应用程序)(
主页:Container(),
NavigatorObserver:[routeObserver],
));
}
类RouteAwareWidget扩展StatefulWidget{
State createState()=>RouteAwareWidgetState();
}
//在小部件的状态下实现RouteAware并订阅它
//
//RouteObserver。
类RouteAwareWidgetState使用RouteAware扩展状态{
@凌驾
void didChangeDependencies(){
super.didChangeDependencies();
subscribe(这是(上下文)的ModalRoute.of);
}
@凌驾
无效处置(){
routeObserver.unsubscribe(此);
super.dispose();
}
@凌驾
void didPush(){
//路线被推到了导航器上,现在是最上面的路线。
}
@凌驾
void didPopNext(){
//覆盖路线从导航器上弹出。
}
@凌驾
小部件构建(BuildContext上下文)=>Container();
}
当我没有看到我的应用程序的主屏幕时,我很难让视频暂停。我应用了这个VisibilityDetector
并抓取了visiblePercentage
来强制暂停或恢复:
VisibilityDetector(
key: Key('visible-video--key-${this.randomkeygenerator}-1'),
onVisibilityChanged: (visibilityInfo) {
var visiblePercentage = visibilityInfo.visibleFraction * 100;
if (visiblePercentage < 1){ //the magic is done here
if(_video_controller != null) {
if(disposed_vid == false) {
_video_controller.pause();
}
}
}else{
if(_video_controller != null) {
if(disposed_vid == false) {
_video_controller.play();
}
}
}
debugPrint(
'Widget ${visibilityInfo.key} is ${visiblePercentage}% visible');
},
child: VideoPlayer(_video_controller)),
@override
void dispose() {
// If the video is playing, pause it.
_video_controller .pause();
_video_controller .dispose();
disposed_vid = true;
super.dispose();
}
VisibilityDetector(
key:key('visible-video--key-${this.randomkeygenerator}-1'),
onVisibilityChanged:(visibilityInfo){
var visiblePercentage=visibilityInfo.visibleFraction*100;
如果(visiblePercentage<1){//,魔法就在这里完成了
如果(\u视频\u控制器!=null){
if(disposed_vid==false){
_视频控制器。暂停();
}
}
}否则{
如果(\u视频\u控制器!=null){
if(disposed_vid==false){
_视频控制器。播放();
}
}
}
调试打印(
'小部件${visibilityInfo.key}是${visiblePercentage}%visible');
},
子:视频播放器(_视频控制器)),
@凌驾
无效处置(){
//如果正在播放视频,请将其暂停。
_视频控制器。暂停();
_video_controller.dispose();
disposed_vid=真;
super.dispose();
}
因为背景路线的动画将被禁用。所以我们可以这样判断它是否在前景中:
final isForeground = TickerMode.of(context);
将其包装到小部件中:
/// Created by ipcjs on 2021/3/23.
class ForegroundDetector extends StatefulWidget {
const ForegroundDetector({
Key? key,
required this.child,
required this.onForegroundChanged,
}) : super(key: key);
final ValueChanged<bool> onForegroundChanged;
final Widget child;
@override
ForegroundDetectorState createState() => ForegroundDetectorState();
}
class ForegroundDetectorState extends State<ForegroundDetector> {
bool get isForeground => _isForeground ?? false;
bool? _isForeground;
@override
Widget build(BuildContext context) {
final isForeground = TickerMode.of(context);
if (_isForeground != isForeground) {
_isForeground = isForeground;
widget.onForegroundChanged(isForeground);
}
return widget.child;
}
}
///由ipcjs于2021/3/23创建。
类ForegroundDetector扩展StatefulWidget{
常数前地探测器({
钥匙?,钥匙,
需要这个孩子,
需要此项。onForegroundChanged,
}):super(key:key);
最终价值在前期发生变化;
最后一个孩子;
@凌驾
ForegroundDetectorState createState()=>ForegroundDetectorState();
}
类ForegroundDetectorState扩展了状态{
bool get isForeground=>\u isForeground??false;
布尔?\u是前景;
@凌驾
小部件构建(构建上下文){
最终isForeground=TickerMode.of(上下文);
如果(_isForeground!=isForeground){
_isForeground=isForeground;
onForegroundChanged(isForeground);
}
返回widget.child;
}
}
不重复。我提到我不是在问关于didChangeAppLifecycleState的问题。我的用例是不同的@tokenyet当你在另一个屏幕时,如果你弹回到视频屏幕,你可以在Navigator.pop(context,parameter)
中传递一个参数,因此在视频屏幕中你将得到参数并相应地做一些事情。看这篇文章哦,我终于知道你不是在简历上写什么了。这更多的是关于页面转换,看起来你有解决办法。为了避免谈论太多的代码,我宁愿在Navigator之前停止。按和等待Navigator.pop
继续视频。如果您没有使用Navigator
,您可能需要提供更多的代码来向我们展示:请键入下面的答案,哪种方法等效于onPause(),哪种方法等效于onResume()?我假设didPush()类似于onResume(),didPop()类似于onPause()。我说得对吗?我的理解正确吗?我对didPopNext()和didPop()感到困惑。didPopNext()是否与onResume()相同?我无法在@software person和等待导航器处获得您的答案。push(…)
作为@Token对我有效,但在评论中提到我创建了一个EventRoute类。它是一个类,用于在创建小部件、推送到前台、推送到后台以及弹出小部件时提供可选回调。所有这些活动都是可选的
/// Created by ipcjs on 2021/3/23.
class ForegroundDetector extends StatefulWidget {
const ForegroundDetector({
Key? key,
required this.child,
required this.onForegroundChanged,
}) : super(key: key);
final ValueChanged<bool> onForegroundChanged;
final Widget child;
@override
ForegroundDetectorState createState() => ForegroundDetectorState();
}
class ForegroundDetectorState extends State<ForegroundDetector> {
bool get isForeground => _isForeground ?? false;
bool? _isForeground;
@override
Widget build(BuildContext context) {
final isForeground = TickerMode.of(context);
if (_isForeground != isForeground) {
_isForeground = isForeground;
widget.onForegroundChanged(isForeground);
}
return widget.child;
}
}