Question

我有一个应用程序，显示状态栏和通知栏中的电池电量和温度。打开应用程序后，我可以在状态栏和通知中看到数据更新。当我退出/关闭应用程序时，状态栏和通知不会更新其值。为什么关闭应用时状态栏和通知栏没有更新？

我使用BroadcastReceiver来显示通知。

public class MyReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    notificationMessage(context, intent);
}

private void notificationMessage(Context context, Intent intent){
    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

    Intent notificationIntent = new Intent(context, MainActivity.class);
    PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);

    int icon = R.drawable.battery_level_images;

    int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
    float cTemperature = (float) intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE, -1)/10;
    float fTemperature = celsiusToFahrenheit(cTemperature);
    float voltage = (float) intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE, -1)/1000;
    int health = intent.getIntExtra(BatteryManager.EXTRA_HEALTH, -1);
    String healthText = getHealthText(health);

    Notification notification = new NotificationCompat.Builder(context)
    .setContentTitle("" + level + "% | " + healthText)
    .setContentText(cTemperature + "\u2103 | " + fTemperature + "\u2109 | " + voltage + "V")
    .setSmallIcon(icon, level)
    .setWhen(0)
    .setProgress(100, level, false)
    .setOngoing(true)
    .setContentIntent(pendingIntent)
    .build();

    notificationManager.notify(0, notification);
}

在我的主要活动课程中，我使用复选框打开通知。

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ............................

    myReceiver = new MyReceiver();

    ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
    batteryStatus = this.registerReceiver(mBatteryInfoReceiver, ifilter);

    ....................

 }

public void onToggleClicked(View view) {
    // Is the toggle on?
    boolean on = ((CheckBox) view).isChecked();

    if (on) {

        batteryStatus = this.registerReceiver(myReceiver, ifilter);
        SavingData.setNotificationState(true);

    } else {

        try{
            this.unregisterReceiver(myReceiver);
        }catch (IllegalArgumentException  iae){
            iae.printStackTrace();  
        }

        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.cancelAll();
        SavingData.setNotificationState(false);
    }
}

这是我的AndroidManifest中的BroadcastReceiver。

 <receiver android:name=".MyReceiver" />

Answer 1

在您的服务中注册BroadcastReceiver并在后台运行。一直运行您的服务可能会耗尽用户的电量。当心:)）

Answer 2

一旦您的活动被销毁，通过BroadcastReceiver注册的registerReceiver()也会消失。您可能在LogCat中发出警告或错误，指出这一点。在BroadcastReceiver消失后，您将停止更新Notification。

应用关闭时，Android状态栏通知不会更新

2 个答案: