当应用程序被杀死/在后台运行时，检测Android 7及更高版本中的连接更改

牛轧糖及以上: 我们必须使用JobScheduler和JobService进行连接更改.

Nougat and Above: We have to use JobScheduler and JobService for Connection Changes.

我可以将其分为三个步骤.

All I can divide this into three steps.

在活动内部注册JobScheduler.另外，启动JobService( 用于处理JobScheduler中的回调的服务.预定的请求 与JobScheduler一起最终落在该服务的"onStartJob"上 方法.)

Register JobScheduler inside activity. Also, Start JobService( Service to handle callbacks from the JobScheduler. Requests scheduled with the JobScheduler ultimately land on this service's "onStartJob" method.)

public class NetworkConnectionActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_network_connection);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        scheduleJob();

    }


    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    private void scheduleJob() {
        JobInfo myJob = new JobInfo.Builder(0, new ComponentName(this, NetworkSchedulerService.class))
                .setRequiresCharging(true)
                .setMinimumLatency(1000)
                .setOverrideDeadline(2000)
                .setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)
                .setPersisted(true)
                .build();

        JobScheduler jobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        jobScheduler.schedule(myJob);
    }

    @Override
    protected void onStop() {
        // A service can be "started" and/or "bound". In this case, it's "started" by this Activity
        // and "bound" to the JobScheduler (also called "Scheduled" by the JobScheduler). This call
        // to stopService() won't prevent scheduled jobs to be processed. However, failing
        // to call stopService() would keep it alive indefinitely.
        stopService(new Intent(this, NetworkSchedulerService.class));
        super.onStop();
    }

    @Override
    protected void onStart() {
        super.onStart();
        // Start service and provide it a way to communicate with this class.
        Intent startServiceIntent = new Intent(this, NetworkSchedulerService.class);
        startService(startServiceIntent);
    }
}

开始和完成工作的服务.

The service to start and finish the job.

public class NetworkSchedulerService extends JobService implements
        ConnectivityReceiver.ConnectivityReceiverListener {

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

    private ConnectivityReceiver mConnectivityReceiver;

    @Override
    public void onCreate() {
        super.onCreate();
        Log.i(TAG, "Service created");
        mConnectivityReceiver = new ConnectivityReceiver(this);
    }



    /**
     * When the app's NetworkConnectionActivity is created, it starts this service. This is so that the
     * activity and this service can communicate back and forth. See "setUiCallback()"
     */
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i(TAG, "onStartCommand");
        return START_NOT_STICKY;
    }


    @Override
    public boolean onStartJob(JobParameters params) {
        Log.i(TAG, "onStartJob" + mConnectivityReceiver);
        registerReceiver(mConnectivityReceiver, new IntentFilter(Constants.CONNECTIVITY_ACTION));
        return true;
    }

    @Override
    public boolean onStopJob(JobParameters params) {
        Log.i(TAG, "onStopJob");
        unregisterReceiver(mConnectivityReceiver);
        return true;
    }

    @Override
    public void onNetworkConnectionChanged(boolean isConnected) {
        String message = isConnected ? "Good! Connected to Internet" : "Sorry! Not connected to internet";
        Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();

    }
}

最后，检查网络连接的接收器类 变化.

Finally, The receiver class which checks the network connection changes.

public class ConnectivityReceiver extends BroadcastReceiver {

    private ConnectivityReceiverListener mConnectivityReceiverListener;

    ConnectivityReceiver(ConnectivityReceiverListener listener) {
        mConnectivityReceiverListener = listener;
    }


    @Override
    public void onReceive(Context context, Intent intent) {
        mConnectivityReceiverListener.onNetworkConnectionChanged(isConnected(context));

    }

    public static boolean isConnected(Context context) {
        ConnectivityManager cm = (ConnectivityManager)
                context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

    public interface ConnectivityReceiverListener {
        void onNetworkConnectionChanged(boolean isConnected);
    }
}

别忘了在清单文件中添加权限和服务.

Don't forget to add permission and service inside manifest file.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.yourpackagename">

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


    <!-- Always required on api < 21, needed to keep a wake lock while your job is running -->
    <uses-permission android:name="android.permission.WAKE_LOCK"/>
    <!-- Required on api < 21 if you are using setRequiredNetworkType(int) -->
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <!-- Required on all api levels if you are using setPersisted(true) -->
    <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=".connectivity.NetworkConnectionActivity"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>


        <!-- Define your service, make sure to add the permision! -->
        <service
            android:name=".connectivity.NetworkSchedulerService"
            android:exported="true"
            android:permission="android.permission.BIND_JOB_SERVICE"/>
    </application>

</manifest>

请参考以下链接以获取更多信息.

Please refer below links for more info.

https://github.com/jiteshmohite/Android-Network-Connectivity

https://github.com/evant/JobSchedulerCompat

https://github.com/googlesamples/android-JobScheduler

https://medium.com/@iiro.krankka/its-to-kiss-by-to-yous-implicit-broadcastreceivers-eefafd9f4f8a