Service is not running in background when app is closed manually

问题

My service is not running is background when started manually and the app closed. I want to start the service automatically when my app is closed.

But in this example when I close the application it prints 'service created' then 'service destroyed' but not prints as 'service running' after 'service created'.

My service code.

public class DataChangeService extends Service {
    Toaster toaster; //

    @Override
    public void onCreate() {
        super.onCreate();
        toaster = new Toaster(getApplication());
        toaster.showMsg("service created");

    }

    public IBinder onBind(Intent intent) {
        return null;

    }

    public int onStartCommand(Intent intent, int flags, int startId) {
        toaster.showMsg("Service is running");
        return START_STICKY;
    }

    public void onDestroy() {
        super.onDestroy();

        toaster.showMsg("service destroyed");
    }
}

My Toaster for printing Toast message

public class Toaster {
    Context context;
    public Toaster(Context context){
        this.context=context;
    }
    public void showMsg(String msg)
    {
        Toast.makeText(context,msg,Toast.LENGTH_SHORT).show();
    }
}

This service is called from onCreate() method.

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startService(new Intent(MainActivity.this,DataChangeService.class));

        }
    }

Below is my Manifest file.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.selfish.servicex">

    <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>
        <service android:name=".DataChangeService" android:exported="true" android:enabled="true"/>
    </application>
</manifest>

My Configuration of android is below

Android Studio 3.6.1
Gradle 5.4.1
Emulator API Level29
Minimum SDK 21 Target 29

Help me to run my service in the background when the app is closed.

来源：https://stackoverflow.com/questions/61028239/service-is-not-running-in-background-when-app-is-closed-manually

标签

android

service

background-service