java - 如何在互联网连接上显示通知？

Question

当设备连接到互联网时，我必须显示通知。
我需要为此一直运行服务吗？

Answer 1

ConnectivityReceiver.java

public class ConnectivityReceiver
    extends BroadcastReceiver {

public static ConnectivityReceiverListener connectivityReceiverListener;

public ConnectivityReceiver() {
    super();
}

@Override
public void onReceive(Context context, Intent arg1) {
    ConnectivityManager cm = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    boolean isConnected = activeNetwork != null
            && activeNetwork.isConnectedOrConnecting();

    if (connectivityReceiverListener != null) {
        connectivityReceiverListener.onNetworkConnectionChanged(isConnected);
    }
}

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


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

MyApplication.java

public class MyApplication extends Application {

private static MyApplication mInstance;

@Override
public void onCreate() {
    super.onCreate();

    mInstance = this;
}

public static synchronized MyApplication getInstance() {
    return mInstance;
}

public void setConnectivityListener(ConnectivityReceiver.ConnectivityReceiverListener listener) {
    ConnectivityReceiver.connectivityReceiverListener = listener;
}}

AndroidManifest.xml

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

<application
    android:name=".MyApplication"
    android:allowBackup="true"
    ...
<receiver
        android:name=".ConnectivityReceiver"
        android:enabled="true">
        <intent-filter>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
        </intent-filter>
    </receiver>
...
</application>

Activity.class

public class MainActivity extends AppCompatActivity
    implements ConnectivityReceiver.ConnectivityReceiverListener {
...
@Override
protected void onResume() {
    super.onResume();

    // register connection status listener
    MyApplication.getInstance().setConnectivityListener(this);
}
...
@Override
public void onNetworkConnectionChanged(boolean isConnected) {
if(isConnected){
Toast.makeText(context, "Internet Connected", Toast.LENGTH_SHORT).show();
}else{Toast.makeText(context, "Internet not Connected", Toast.LENGTH_SHORT).show();}   
}}