即使应用关闭，也要监听时区变化

Question

我正在尝试监听时区更改，即使我的Android应用程序已经关闭。

我尝试过的：

1. 我找到了一个意图行动。它是TIME_ZONE_CHANGED。然而，正如文档所说，它是受保护的意图，只能由系统发送，并且可能不允许将其作为隐式广播。

2. 我试过AlarmManager，但无法找到确切的时区更改事件。

3. 我在应用程序服务的线程中使用了 schedululeAtFixedRate。它完美地工作了。但我不想让它监听每个小时的更改，我只想要监听时区更改，就像我上面提到的那样。

---

编辑：

MainActivity

public static final String CHANNEL_ID = "49";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    createNotificationChannel();
    startService(new Intent(this,AppService.class));
}

 private void createNotificationChannel() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence c_name = getString(R.string.notification_channel_name);
        String c_desc = getString(R.string.notification_channel_description);
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel notificationChannel = new NotificationChannel(CHANNEL_ID,c_name,importance);
        notificationChannel.setDescription(c_desc);
        NotificationManager manager = getSystemService(NotificationManager.class);
        manager.createNotificationChannel(notificationChannel);
    }
}

清单文件

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:usesCleartextTraffic="true">
    <receiver
        android:name=".TimeChangedReceiver"
        android:enabled="true"
        android:exported="true">

        <intent-filter >
            <action android:name="android.intent.action.TIMEZONE_CHANGED"/>
        </intent-filter>

    </receiver>

    <service
        android:name=".AppService"
        android:enabled="true"
        android:exported="true" />

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

接收器类

package com.example.gridview;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;

public class TimeChangedReceiver extends BroadcastReceiver {

private static int NOTIFICATION_ID = 1;

@Override
public void onReceive(Context context, Intent intent) {
    // TODO: This method is called when the BroadcastReceiver is receiving
    // an Intent broadcast.
    StringBuilder sb = new StringBuilder("Timezone is changed 
    YAY!,executed for "+NOTIFICATION_ID+" times.");
    if (intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
        sb.append("\n Status: Ok.");
    }
  
    NotificationCompat.Builder builder = new 
    NotificationCompat.Builder(context,MainActivity.CHANNEL_ID)
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .setContentText(sb.toString())
            .setSmallIcon(R.drawable.ic_launcher_background)
            .setContentTitle("Hey!");
    NotificationManagerCompat notificationManager = 
    NotificationManagerCompat.from(context);
    notificationManager.notify(NOTIFICATION_ID,builder.build());
    NOTIFICATION_ID++;
}

}

- Snefru Clone

Answer 1

你应该为 "android.intent.action.TIMEZONE_CHANGED" （又称Intent.ACTION_TIMEZONE_CHANGED）注册清单接收器。这是一种隐式广播例外，不受 Android 8.0+ 中注册清单接收器的限制。

像这样的清单接收器将是在你的应用程序未运行时检测此类事件的唯一方法。

- Ryan M

---

嗨，我尝试了你的解决方案。我的接收器类没有得到更改。我正在编辑问题。 - Snefru Clone