Android 如何从Worker中的活动访问对象？（定期更改通知）
我想定期更改Worker中通知的文本。（androidx.work.WorkManager） 我的主要活动是这样的Android 如何从Worker中的活动访问对象？（定期更改通知）,android,androidx,worker,android-workmanager,Android,Androidx,Worker,Android Workmanager,我想定期更改Worker中通知的文本。（androidx.work.WorkManager） 我的主要活动是这样的 public class MainActivity extends AppCompatActivity { ... private NotificationManagerCompat notificationManagerCompat; private NotificationCompat.Builder notificationBuilder;
public class MainActivity extends AppCompatActivity {
...
private NotificationManagerCompat notificationManagerCompat;
private NotificationCompat.Builder notificationBuilder;
...
private void startNotification() {
...
notificationBuilder =
new NotificationCompat.Builder(getApplicationContext(), warnotifier_notification_channel)
.setSmallIcon(R.drawable.notification_icon)
.setContentTitle(notificationTitle)
.setContentText(notificationText)
.setContentIntent(pendingIntent)
.setAutoCancel(true)
.setPriority(NotificationCompat.PRIORITY_LOW)
.setOngoing(true);
notificationManagerCompat = NotificationManagerCompat.from(getApplicationContext());
notificationManagerCompat.notify(1, notificationBuilder.build());
PeriodicWorkRequest periodicWorkRequest = new PeriodicWorkRequest.Builder(NotificationWorker.class, PeriodicWorkRequest.MIN_PERIODIC_INTERVAL_MILLIS, TimeUnit.MILLISECONDS)
.addTag(workTag)
.build();
WorkManager.getInstance(getApplicationContext()).enqueue(periodicWorkRequest);
}
...
}
public class NotificationWorker extends Worker {
public NotificationWorker(@NonNull Context context, @NonNull WorkerParameters params) {
super(context, params);
}
@NonNull
@Override
public Result doWork() {
String notificationText = "Time: " + calendar.get(Calendar.HOUR_OF_DAY) + ":" + calendar.get(Calendar.MINUTE) + ":" + calendar.get(Calendar.SECOND);
notificationBuilder.setContentText(notificationText);
notificationManagerCompat.notify(1, notificationBuilder.build());
return Result.success();
}
}
public class MainActivity extends AppCompatActivity {
...
private NotificationManagerCompat notificationManagerCompat;
private NotificationCompat.Builder notificationBuilder;
...
private void startNotification() {
...
notificationBuilder =
new NotificationCompat.Builder(getApplicationContext(), warnotifier_notification_channel)
.setSmallIcon(R.drawable.notification_icon)
.setContentTitle(notificationTitle)
.setContentText(notificationText)
.setContentIntent(pendingIntent)
.setAutoCancel(true)
.setPriority(NotificationCompat.PRIORITY_LOW)
.setOngoing(true);
notificationManagerCompat = NotificationManagerCompat.from(getApplicationContext());
notificationManagerCompat.notify(1, notificationBuilder.build());
PeriodicWorkRequest periodicWorkRequest = new PeriodicWorkRequest.Builder(NotificationWorker.class, PeriodicWorkRequest.MIN_PERIODIC_INTERVAL_MILLIS, TimeUnit.MILLISECONDS)
.addTag(workTag)
.build();
WorkManager.getInstance(getApplicationContext()).enqueue(periodicWorkRequest);
}
...
}
public class NotificationWorker extends Worker {
public NotificationWorker(@NonNull Context context, @NonNull WorkerParameters params) {
super(context, params);
}
@NonNull
@Override
public Result doWork() {
String notificationText = "Time: " + calendar.get(Calendar.HOUR_OF_DAY) + ":" + calendar.get(Calendar.MINUTE) + ":" + calendar.get(Calendar.SECOND);
notificationBuilder.setContentText(notificationText);
notificationManagerCompat.notify(1, notificationBuilder.build());
return Result.success();
}
}
periodicWorkRequest.setInputData（inputData）有什么想法吗？提前感谢。您可以创建一个具有相同ID的通知（，因此为您的通知维护一个固定ID）并通知。它会自动更新现有的
NotificationManager notificationManager = (NotificationManager) getSystemService(
Context.NOTIFICATION_SERVICE);
if (notificationManager != null) {
Create a notification object with same ID as previous one and use notify to update the existing one.
}
main活动中添加NotificationWorker
类
正如您提到的，您只想从Worker
类访问NotificationManagerCompat
和NotificationCompat.Builder
，并且没有任何限制，因此要生成通知，您已经将上下文传递给Worker
类构造函数，您还可以从Worker
类调用getApplicationContext（）
。
我已经测试过了，没有任何问题
希望有帮助。如果您有任何疑问，欢迎光临
更新
在我的Worker类中，我想访问notificationManagerCompat
以及我在MainActivity
中创建的notificationBuilder
实例
您不必在main活动中创建notificationManagerCompat
和notificationBuilder
实例，通常可以在NotificationWorker
中创建它们
这是您的代码的演示
public class NotificationWorker extends Worker {
private final NotificationManagerCompat notificationManagerCompat;
private final NotificationCompat.Builder notificationBuilder;
public NotificationWorker(@NonNull Context context, @NonNull WorkerParameters params) {
super(context, params);
PendingIntent pendingIntent = PendingIntent.getActivity
(context, 0, new Intent(context, MainActivity.class),
PendingIntent.FLAG_UPDATE_CURRENT);
notificationBuilder =
new NotificationCompat.Builder(getApplicationContext(), warnotifier_notification_channel)
.setSmallIcon(R.drawable.notification_icon)
.setContentTitle(notificationTitle)
.setContentText(notificationText)
.setContentIntent(pendingIntent)
.setAutoCancel(true)
.setPriority(NotificationCompat.PRIORITY_LOW)
.setOngoing(true);
notificationManagerCompat = NotificationManagerCompat.from(getApplicationContext());
}
@NonNull
@Override
public Result doWork() {
Calendar calendar = new GregorianCalendar();
String notificationText = "Time: " + calendar.get(Calendar.HOUR_OF_DAY) + ":" + calendar.get(Calendar.MINUTE) + ":" + calendar.get(Calendar.SECOND);
notificationBuilder.setContentText(notificationText);
notificationManagerCompat.notify(1, notificationBuilder.build());
return Result.success();
}
}
您可以使用R.string.XX从res/string获取notificationTitle
，notificationText
，使用R.drawable.XX从res/drawable获取通知图标
有了它，您可以从您的工作人员那里使用NotificationManagerCompat
和NotificationCompat.Builder
，您所需要的只是一个上下文，无需执行任何活动
希望这能回答您的问题。但是上下文如何帮助我访问notificationManagerCompat
和notificationBuilder
？我无法将其强制转换为MainActivity，因为它是应用程序上下文。@Colin您希望在MainActivity上访问哪种类型的对象？在我的工人类中，我希望访问我在MainActivity中创建的notificationManagerCompat
和notificationBuilder
实例。我现在正在使用androidbash的解决方案，除非你有更好的想法。嗨@Colin，你可以在你的自定义Worker
中创建这些实例，而不是MainActivity
；您通常可以在Worker类中调用getApplicationContext（）
，或者在其构造函数中使用context
参数。。请检查更新的应答OK，它看起来像是在Worker中使用新的NotificationCompat.Builder
和NotificationManagerCompat
实例，但通知的ID相同。您为什么要使用通知管理器
？我不需要它来更新我的通知。这种方式有什么缺点吗？我现在不仅替换了通知的文本，还替换了整个通知。您可以使用此NotificationManagerCompat而不是NotificationManager