How do I use a service to monitor Orientation change in Android

问题

I'm writing a Widget that will display a countdown timer. I have the widget working the way I want it until I flip the phone from landscape to portrait. My widget does not update and goes to it's initial state at start of the widget until an onupdate is called by my recurring alarm. I would like to call an onupdate manually once the orientation changes to update my widget I've been researching this for a while now and I've found out that I need to use a Service which will monitor the orientation changes and call my onupdate for my widget.

My problem is I can't find a straight answer as to how to use a service to monitor the change. I've seen that with an activity I can add android:configChanges="orientation|keyboardHidden" to the manifest for an activity and use a onConfigurationChanged, but can I do this for a service. If so how? Is there a better way to monitor the orientation change? I've also read on the internet that a service isn't the best way to do this either.

I've seen tutorials for creating orientation listeners but they seem to use depreciated function calls.

Thanks in Advance

回答1:

Service#onConfigurationChanged(Configuration newConfig) works for me. No need to register Receivers for my opinion. I also did not add any filter to AndroidManifest. Did I miss something in the discussion since nobody suggested this solution? My Service is running on foreground.

Just place inside your service:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    //Your handling
}

回答2:

Please find below an example which does what you ask for, hope this helps.

public class ScreenOrientationListener extends Activity {

    private static final String TAG = "ScreenOrientationListener";

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

        mContext = this;

        setContentView(R.layout.main);

        startService( new Intent(this, MyService.class) );
    }
}

and here comes MyService class

public class MyService extends Service {
    private static final String TAG = "MyService";

    private static final String BCAST_CONFIGCHANGED = "android.intent.action.CONFIGURATION_CHANGED";
    private static Context mContext;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        Log.d(TAG, "onCreate()");

        mContext = this;

        IntentFilter filter = new IntentFilter();
        filter.addAction(BCAST_CONFIGCHANGED);
        this.registerReceiver(mBroadcastReceiver, filter);
    }

    @Override
    public void onDestroy() {           
        Log.d(TAG, "onDestroy()");
        //Unregister receiver to avoid memory leaks
        mContext.unregisterReceiver(mBroadcastReceiver);
    }

    @Override
    public void onStart(Intent intent, int startid) {
        Log.d(TAG, "onStart()");
    }

    public BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent myIntent) {

            if ( myIntent.getAction().equals( BCAST_CONFIGCHANGED ) ) {

                Log.d(TAG, "received->" + BCAST_CONFIGCHANGED);


                if(getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE){
                    // it's Landscape
                    Log.d(TAG, "LANDSCAPE");
                }
                else {
                    Log.d(TAG, "PORTRAIT");
                }
            }
        }
    };
}

and here is the part to define MyService in manifest file

<!-- Services -->
        <service android:enabled="true"  android:name="com.wareninja.android.external.screenorientationlistener.services.MyService">
            <intent-filter>
                <action android:name="android.intent.action.CONFIGURATION_CHANGED"/>
            </intent-filter>
        </service>

回答3:

You could create a BroadcastReceiver that listens for Intent.ACTION_CONFIGURATION_CHANGED (android.intent.action.CONFIGURATION_CHANGED)

Note that it does say:

You can not receive this through components declared in manifests, only by explicitly registering for it with Context.registerReceiver().

Which means you can't register your reciever in the manifest file. You would have to register it in code.

then get the configuration and check what the orientation is as Floern stated.

回答4:

I would suggest you use an OrientationEventListener object. It does exactly what you are looking for and it is not deprecated. It's been around since API level 3.

来源：https://stackoverflow.com/questions/4625167/how-do-i-use-a-service-to-monitor-orientation-change-in-android

标签

android

service

android-widget

screen-orientation