flutter - Flutter:来自后台任务的通知导航,没有上下文问题
问题描述
我的应用程序执行以下操作:它使用 Flutter Workmanager 运行后台任务,该任务检查一些值,然后通过 Flutter Local Notification 引发通知。在 FlutterLocalNotifications Plugin 的初始化方法中,我可以指定一个内联函数,它应该导航到一个页面。由于我没有 Builder 上下文,我必须使用带有 OnGenerateRoute 的导航键将用户转发到站点。但是,这不起作用,我不知道为什么。我知道当应用程序被杀死时,这段代码很有用。
示例代码
final NotificationAppLaunchDetails? notificationAppLaunchDetails =
await flutterLocalNotificationsPlugin.getNotificationAppLaunchDetails();
String initialRoute = HomePage.routeName;
if (notificationAppLaunchDetails?.didNotificationLaunchApp ?? false) {
selectedNotificationPayload = notificationAppLaunchDetails!.payload;
initialRoute = SecondPage.routeName;
}
但是当应用程序仍然存在时该怎么办?我的项目代码如下所示。
主要飞镖
void main() {
WidgetsFlutterBinding.ensureInitialized();
Workmanager().initialize(callbackDispatcher, isInDebugMode: true);
Workmanager().registerPeriodicTask("1", "test",frequency: Duration(minutes: 15));
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
State createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
initialRoute: "/",
navigatorKey: NavigationService.navigatorKey,
onGenerateRoute: RouteGenerator.generateRoute
);
}
}
RouteGenerator.dart
class RouteGenerator {
static Route<dynamic> generateRoute(RouteSettings settings) {
final args = settings.arguments;
switch(settings.name) {
case '/first':
return MaterialPageRoute(builder: (_) => Page1(title: "First"));
case '/second':
return MaterialPageRoute(builder: (_) => Page2(title: "Second"));
case '/third':
return MaterialPageRoute(builder: (_) => Page3(title: "Third"));
case '/fourth':
return MaterialPageRoute(builder: (_) => Page4(title: "Fourth"));
}
return MaterialPageRoute(builder: (_) => Page0(title: "Root!"));
}
}
class NavigationService {
static final GlobalKey<NavigatorState> navigatorKey = new GlobalKey<NavigatorState>();
static Future<dynamic> navigateTo(String routeName) {
return navigatorKey.currentState!.pushNamed(routeName);
}
}
服务.dart
class DevHttpOverrides extends HttpOverrides {
@override
HttpClient createHttpClient(SecurityContext? context) {
return super.createHttpClient(context)
..badCertificateCallback = (X509Certificate cert, String host, int port) => true;
}
}
void callbackDispatcher() {
Workmanager().executeTask((task, inputData) async{
HttpOverrides.global = new DevHttpOverrides();
var url = 'https://172.16.0.100/handler.php?page=settings';
http.Response response = await http.get(Uri.parse(url));
List<dynamic> list = jsonDecode(response.body);
SharedPreferences prefs = await SharedPreferences.getInstance();
var usage = "Beides";
var checkValue = "temp_out";
var borderValueString = "14.9";
var checktype = "Grenzwert überschreiten";
var borderValueDouble;
var message = "";
if(usage != "Nur Home Widgets" && checkValue != "" && borderValueString != "" && checktype != "")
{
var value = list[0][checkValue];
if (double.tryParse(borderValueString) != null && double.tryParse(value) != null)
{
borderValueDouble = double.parse(borderValueString);
value = double.parse(value);
}
if (checktype == "Grenzwert unterschreiten")
{
if (borderValueDouble is double)
{
if (value <= borderValueDouble)
{
message = "Grenzwert unterschritten";
}
}
}
else if (checktype == "Grenzwert überschreiten")
{
if (borderValueDouble is double)
{
if (value >= borderValueDouble)
{
message = "Grenzwert überschritten";
}
}
}
else if (checktype == "Entspricht Grenzwert")
{
if (borderValueDouble == value)
{
message = "Grenzwert erreicht";
}
}
}
if(message != "")
{
FlutterLocalNotificationsPlugin flip = new FlutterLocalNotificationsPlugin();
var android = new AndroidInitializationSettings('@mipmap/ic_launcher');
var ios = new IOSInitializationSettings();
var settings = new InitializationSettings(android: android, iOS: ios);
flip.initialize(settings, onSelectNotification: (String? payload) async {
await NavigationService.navigatorKey.currentState!.push(MaterialPageRoute(builder: (context) => Page4(title: "Hello")));
});
var androidPlatformChannelSpecifics = new AndroidNotificationDetails(
'1',
'weatherstation',
'Notify when values change',
importance: Importance.max,
priority: Priority.high
);
var iOSPlatformChannelSpecifics = new IOSNotificationDetails();
var platformChannelSpecifics = new NotificationDetails(
android: androidPlatformChannelSpecifics,
iOS: iOSPlatformChannelSpecifics);
await flip.show(0, message,
'App öffnen für weitere Details',
platformChannelSpecifics, payload: 'Default_Sound'
);
}
return Future.value(true);
});
}
解决方案
你找到解决办法了吗?我还在开发一个 Android 应用程序,它更新 firestore 数据库中的用户数据(每隔 15 分钟)并向用户发送通知(这两个任务都使用 Flutter workmanager_plugin 在后台发生)。当用户点击通知时,他应该被导航到显示来自数据库的最新数据的路线。
前 2 个后台任务成功发生,但是当点击通知时没有发生任何事情。我还使用 GlobalKey 键来获取 MaterialApp 小部件的上下文,以便可以推送路由 Route。
似乎 FlutterLocalNotificationsPlugin.initialize() 方法的 onSelectNotification 属性不适用于 workmanager 插件。我还在其中添加了一条打印语句,但控制台中没有显示任何内容。我想也许我的 Globalkey 有一些错误,但是当我尝试在非后台任务中导航页面时它成功地发生了,同样 onSelectNotification 对非工作管理器任务非常有效。
void callbackDispatcher() {
Workmanager().executeTask((task, data) async {
if(task=='showNotification'){
FlutterLocalNotificationsPlugin notifPlugin =
FlutterLocalNotificationsPlugin();
NotificationDetails notificationDetails = NotificationDetails(
android: AndroidNotificationDetails(
'main_channel',
'Main Channel',
'Main Notification Channel',
importance: Importance.max,
priority: Priority.high,
),
);
await notifPlugin.initialize(
InitializationSettings(
android: AndroidInitializationSettings('ic_launcher')),
onSelectNotification: (String? payload) async {
print('Inside on select Route Navigator. Route= $payload');
switch (payload!) {
case 'Home':
// navigatorKey is GlobalKey
navigatorKey.currentState!
.push(MaterialPageRoute(builder: (context) => Home()));
break;
case 'Auth':
navigatorKey.currentState!
.push(MaterialPageRoute(builder: (context) => Auth()));
break;
case 'Details':
navigatorKey.currentState!
.push(MaterialPageRoute(builder: (context) => UserDetails()));
break;
}
});
await notifPlugin.show(id, title, body, notificationDetails, payload:payload);
}
return Future.value(true);
}
}
单击通知时。以下消息应打印在控制台上:“在选择路线导航器内部。路线 = 详细信息”,他应该在用户详细信息页面上导航,但似乎没有发生任何事情。
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