วิธีทำให้ Notification คงอยู่หลัง Reboot โทรศัพท์ Android

ภาพรวม

บทความนี้สาธิตวิธีทำให้ Notification คงอยู่ (Persist) หลังจากโทรศัพท์ Reboot โดยใช้ BroadcastReceiver ที่รับฟัง BOOT_COMPLETED

ขั้นตอนที่ 1: สร้างโปรเจกต์ใหม่

Android Studio → File → New Project → Empty Activity

ขั้นตอนที่ 2: Layout (res/layout/activity_main.xml)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:tools="https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".MainActivity" />

ขั้นตอนที่ 3: MainActivity (src/MainActivity.java)

package app.tutorialspoint.com.notifyme;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

ขั้นตอนที่ 4: USBStateReceiver (src/USBStateReceiver.java)

package app.tutorialspoint.com.notifyme;

import android.annotation.SuppressLint;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

public class USBStateReceiver extends BroadcastReceiver {
    public static final String NOTIFICATION_CHANNEL_ID = "10001";
    private final static String default_notification_channel_id = "default";
    boolean connected = true;

    @SuppressLint("UnsafeProtectedBroadcastReceiver")
    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, default_notification_channel_id);
        builder.setContentTitle("USB - Notification");
        String action = intent.getAction();
        Log.e("USB", action);
        
        if (action != null) {
            builder.setContentText("Connected");
            builder.setSmallIcon(R.drawable.ic_launcher_foreground);
            builder.setAutoCancel(true);
            builder.setChannelId(NOTIFICATION_CHANNEL_ID);
            
            Notification notification = builder.build();
            NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
                int importance = NotificationManager.IMPORTANCE_HIGH;
                NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "NOTIFICATION_CHANNEL_NAME", importance);
                assert notificationManager != null;
                notificationManager.createNotificationChannel(notificationChannel);
            }
            
            assert notificationManager != null;
            if (connected) {
                notificationManager.notify(1, notification);
                connected = false;
            } else {
                notificationManager.cancel(1);
                connected = true;
            }
        }
    }
}

ขั้นตอนที่ 5: AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
    package="app.tutorialspoint.com.notifyme">
    <uses-permission android:name="android.permission.VIBRATE" />
    <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">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver android:name=".USBStateReceiver">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
            </intent-filter>
        </receiver>
    </application>
</manifest>

การทดสอบ

ติดตั้งแอป Reboot โทรศัพท์ การแจ้งเตือนจะแสดงอัตโนมัติหลัง Boot เสร็จสิ้น