0. Learning articles

Refer to the following Blog without any extra code

https://blog.csdn.net/wanghang1208/article/details/49905403

The original Baidu guard notice bar is similar to this principle, very good

1. Demonstration results

Data source

log monitored

03-24 14:37:04.264 6155-6155/com.lava.noticeobser D/MyNotificationListenService: onNotificationRemoved
03-24 14:39:19.928 6155-6155/com.lava.noticeobser D/MyNotificationListenService: onNotificationPosted
 03-24 14:39:19.928 6155-6155/com.lava.noticeobser I/MyNotificationListenService: notify msg: title = the temperature in many places in the North has reached a new high, and a new round of rainfall in the south is coming. Details →, when = 1521873559186, contenttitle = obvious warming range! , contentText = the temperature in many places in the North has reached a new high, and a new round of rainfall is coming from the south. Details →, contentText=
03-24 14:39:20.235 6155-6155/com.lava.noticeobser D/MyNotificationListenService: onNotificationPosted
 03-24 14:39:20.235 6155-6155/com.lava.noticeobser I/MyNotificationListenService: notify msg: title = please eat these delicacies in the spring anyway →, when = 1521873560030, contenttitle = miss one year! , contentText = please eat these delicacies in the spring anyway →, contentSubtext=
03-24 14:39:54.276 6155-6155/com.lava.noticeobser D/MyNotificationListenService: onNotificationPosted
 03-24 14:39:54.276 6155-6155/com.lava.noticeobser I/MyNotificationListenService: notify msg: title = saving screenshot..., when = 1521873594184, contenttitle = saving screenshot..., contentText = saving screenshot. ,contentSubtext=
03-24 14:39:55.156 6155-6155/com.lava.noticeobser D/MyNotificationListenService: onNotificationPosted
 03-24 14:39:55.156 6155-6155/com.lava.noticeobser I/MyNotificationListenService: notify msg: title = saving screenshot..., when = 1521873595096, contenttitle = screenshot captured. , contentText = Click to view your screenshot. ,contentSubtext=

2. source code

1. MyNotificationListenService is responsible for listening to messages

package com.lava.noticeobser;

import android.app.Notification;
import android.os.Build;
import android.os.Bundle;
import android.service.notification.NotificationListenerService;
import android.service.notification.StatusBarNotification;
import android.util.Log;

import java.lang.reflect.Field;

public class MyNotificationListenService extends NotificationListenerService {


    private static final String TAG = MyNotificationListenService.class.getSimpleName();

    @Override
    public void onNotificationPosted(StatusBarNotification sbn) {
        super.onNotificationPosted(sbn);
        Log.d(TAG, "onNotificationPosted");

        Notification n = sbn.getNotification();
        if (n == null) {
            return;
        }
        // Title and time
        String title = "";
        if (n.tickerText != null) {
            title = n.tickerText.toString();
        }
        long when = n.when;
        // Other information exists in a bundle, which is private before Android 4.3 and needs to be obtained through reflection; it can be obtained directly after Android 4.3
        Bundle bundle = null;
        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.JELLY_BEAN_MR2) {
            // android 4.3
            try {
                Field field = Notification.class.getDeclaredField("extras");
                bundle = (Bundle) field.get(n);
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2) {
            // After android 4.3
            bundle = n.extras;
        }
        // Content title, content and sub content
        String contentTitle = bundle.getString(Notification.EXTRA_TITLE);
        if (contentTitle == null) {
            contentTitle = "";
        }
        String contentText = bundle.getString(Notification.EXTRA_TEXT);
        if (contentText == null) {
            contentText = "";
        }
        String contentSubtext = bundle.getString(Notification.EXTRA_SUB_TEXT);
        if (contentSubtext == null) {
            contentSubtext = "";
        }

        Log.i(TAG, "notify msg: title=" + title + " ,when=" + when
                + " ,contentTitle=" + contentTitle + " ,contentText="
                + contentText + " ,contentSubtext=" + contentSubtext);
    }

    @Override
    public void onNotificationRemoved(StatusBarNotification sbn) {
        super.onNotificationRemoved(sbn);
        Log.d(TAG, "onNotificationRemoved");
    }
}

1. Mainfest.xml to assist MyNotificationListenService

        <service
            android:name=".MyNotificationListenService"
            android:label="mynotifyservice"
            android:permission="android.permission.BIND_NOTIFICATION_LISTENER_SERVICE" >
            <intent-filter>
                <action android:name="android.service.notification.NotificationListenerService" />
            </intent-filter>
        </service>

1. Opening service

package com.lava.noticeobser;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

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

        startNotificationListenService();
    }

    // Sending notice
    public void sendNotice(View view) {
        NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        Notification n;
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB) {
            // android 3.0before
            n = new Notification(R.mipmap.ic_launcher, "title",
                    System.currentTimeMillis());
        } else {
            // android 3.0after
            n = new Notification.Builder(MainActivity.this)
                    .setSmallIcon(R.mipmap.ic_launcher).setTicker("title")
                    .setContentTitle("content title")
                    .setContentText("content text").setSubText("sub text")
                    .setWhen(System.currentTimeMillis()).build();
        }
        manager.notify(0, n);
    }

    // Jump to the authority interface of service notification
    public void settingsNotice(View view) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            Intent intent = new Intent(
                    "android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
            startActivity(intent);
        } else {
            Toast.makeText(MainActivity.this, "This function is not supported by the system of the phone", Toast.LENGTH_SHORT)
                    .show();
        }
    }

    // Start listening message notification service
    private void startNotificationListenService() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            Intent intent = new Intent(MainActivity.this,
                    MyNotificationListenService.class);
            startService(intent);
        } else {
            Toast.makeText(MainActivity.this, "This function is not supported by the system of the phone", Toast.LENGTH_SHORT)
                    .show();
        }
    }
}

1. Simple and rough layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.lava.noticeobser.MainActivity"
    android:orientation="vertical">

    <Button
        android:onClick="sendNotice"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send notice" />

    <Button
        android:onClick="settingsNotice"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Enable listening permission" />
</LinearLayout>