1. 预知识（安卓版本）

    public static final int BASE = 1;                    //Android 1.0public static final int BASE_1_1 = 2;                //Android 1.1public static final int CUPCAKE = 3;                 //Android 1.5public static final int DONUT = 4;                   //Android 1.6public static final int ECLAIR = 5;                  //Android 2.0public static final int ECLAIR_0_1 = 6;              //Android 2.0.1public static final int ECLAIR_MR1 = 7;              //Android 2.1public static final int FROYO = 8;                   //Android 2.2public static final int GINGERBREAD = 9;             //Android 2.3public static final int HONEYCOMB = 11;              //Android 3.0public static final int HONEYCOMB_MR1 = 12;          //Android 3.1public static final int HONEYCOMB_MR2 = 13;          //Android 3.2public static final int ICE_CREAM_SANDWICH = 14;     //Android 4.0public static final int ICE_CREAM_SANDWICH_MR1 = 15; //Android 4.0.3public static final int JELLY_BEAN = 16;             //Android 4.1public static final int JELLY_BEAN_MR1 = 17;         //Android 4.2public static final int JELLY_BEAN_MR2 = 18;         //Android 4.3public static final int KITKAT = 19;                 //Android 4.4public static final int KITKAT_WATCH = 20;           //Android 4.4Wpublic static final int L = 21;                      //Android 5.0public static final int LOLLIPOP = 21;               //Android 5.0public static final int LOLLIPOP_MR1 = 22;           //Android 5.1public static final int M = 23;                      //Android 6.0public static final int N = 24;                      //Android 7.0public static final int N_MR1 = 25;                  //Android 7.1public static final int O = 26;                      //Android 8.0public static final int O_MR1 = 27;                  //Android 8.1public static final int P = 28;                      //Android 9public static final int Q = 29;                      //Android 10public static final int R = 30;                      //Android 11public static final int S = 31;                      //Android 12

2. NotificationChannel

2.1 在 Android O 版本以上（也即是 Android 10以上的版本）需要设置 NotificationChannel，主要用来设置通知的程度；

• NotificationManager.IMPORTANCE_NONE：关闭通知
• NotificationManager.IMPORTANCE_MIN：开启通知，无提示音、无弹框、状态栏无显示
• NotificationManager.IMPORTANCE_LOW：开启通知，无提示音、无弹框、状态栏显示
• NotificationManager.IMPORTANCE_DEFAULT：开启通知，有提示音、无弹框、状态栏显示
• NotificationManager.IMPORTANCE_HIGH：开启通知，有提示音、有弹框、状态栏显示

2.2 同时，支持在锁屏上设置信息的敏感度

• VISIBILITY_PUBLIC：所有信息展示
• VISIBILITY_PRIVATE：隐藏敏感信息（就像微信，锁屏不能看到具体信息一样）
• VISIBILITY_SECRET：不展示

2.3 具体逻辑代码

// android O 版本以上
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {// 设置通知程度notificationChannel = new NotificationChannel("通道ID","通道名称",// 重要程度：见2.1节NotificationManager.IMPORTANCE_HIGH);// 锁屏信息的敏感度：见2.2节notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);// 获取通知服务管理器，并创建通道notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);notificationManager.createNotificationChannel(notificationChannel);}

3. 设置通知

// 跳转的页面
intent = new Intent(getApplicationContext(), MyServiceActivity.class); // 对Intent进行包装，因为不是马上跳转，而是悬挂通知栏，点击后跳转PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_MUTABLE);  
// 跟第二章节一样，O版本以上要设置通道等级if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {notification = new Notification.Builder(this, NOTIFICATION_CHANNEL_ID)// 图标.setSmallIcon(R.mipmap.ic_launcher)// 通知标题.setContentTitle("标题：测试文案")// 通知内容.setContentText("内容：你好,点击打开app主页")// 跳转页面.setContentIntent(pendingIntent)// 点击删除.setDeleteIntent(pendingIntent).build();}// 前台展示startForeground("前台通知ID", notification);return Service.START_STICKY;

4. 在AndroidManifest.xml开启通知权限和注册服务

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"package="com.example.myapplication">// 开启权限<uses-permission android:name="android.permission.FOREGROUND_SERVICE" /><applicationandroid:name="org.litepal.LitePalApplication"android:usesCleartextTraffic="true"android:allowBackup="true"android:dataExtractionRules="@xml/data_extraction_rules"android:fullBackupContent="@xml/backup_rules"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:roundIcon="@mipmap/ic_launcher_round"android:supportsRtl="true"android:theme="@style/Theme.MyApplication"tools:targetApi="31">// 注册服务<service android:name=".services.FrontService"android:exported="true"android:enabled="true" /></application>
</manifest>

5. 设置主活动

public class MyServiceActivity extends AppCompatActivity {@Overrideprotected void onCreate(@Nullable Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.myservice_demo);// 开启服务findViewById(R.id.start_service).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(MyServiceActivity.this, MyService.class);startService(intent);}});// 关闭服务findViewById(R.id.stop_service).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(MyServiceActivity.this, MyService.class);stopService(intent);}});// 默认开启服务Intent service = new Intent(getApplicationContext(), FrontService.class);startService(service);}
}