Android App orientation change restarts activity

Question

I have an activity and it is getting restarted whenever orientation changes. I have written code to prevent activity restart upon change in orientation in the manifest file as given below:

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.sample.appname.MainActivity"
        android:label="@string/app_name"
        android:configChanges="orientation|keyboardHidden"
        >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

In the above code snippet android:configChanges="orientation|keyboardHidden" is supposed to do the work for me but the activity is still getting restarted. Please let me know how to correct it.

Unless you have a very good reason to, you should not try to prevent the activity from being recreated. Instead you should properly manage your activity state and save any necessary state in `onSaveInstanceState()`, then use the `Bundle` provided in `onCreate()` to restore state appropriately. — Karakuri, Mar 26 '16 at 19:10

score 9 · Accepted Answer · edited Jun 20 '20 at 09:12

Actually you shouldn't prevent the Activity to be restarted. It is neccessary to recreate the Activity after a rotation change for several reasons. One of it is that the layout has to be inflated to deal with the changed screen size and things like that (it's easy to imagine that the layout is totally different in portrait than it is in landscape mode). However, there is a way you can tell the system that you deal with the screen changes by yourself. Therefore change the line in your manifest

android:configChanges="orientation|keyboardHidden"

to

android:configChanges="orientation|screenSize"

The activity won't be recreated then. You'll get a callback via the onConfigurationChanged() method so you can do something when the orientation has changed. If you don't want to do anything when the configuration has changed, just don't override the onConfigurationMethod() in your Activity. Read this section in the Android Developers API Guide for more information.

I got this from this answer. There are two more approaches in the answer but I think the one I described above is the best in your case.

EDIT: Maybe you have to add keyboard|keyboardHidden to the android:configChanges attribute as well, as stated in this answer

EDIT #2: If you want to retrieve the current orientation of the device you can call

Activity.getResources().getConfiguration().orientation

which will return the constants ORIENTATION_PORTRAIT or ORIENTATION_LANDSCAPE.

If you're interested in the exact rotation angle, use

int rotation =  getWindowManager().getDefaultDisplay().getRotation();

and implement a differentiation with something like a switch case described here.

And a third way to determine the device's rotation is getRequestedOrientation() which will return a constant defined in the documentation

Can we somehow determine if the orientation has been changed inside onCreate event? — , Mar 26 '16 at 19:15
@MakeInIndia I've updated my answer, I hope this helps. Feel free to accept it if it helped you solving your problem — l7r7, Mar 26 '16 at 19:52

score 0 · Answer 2 · answered Mar 26 '16 at 18:37

android:configChanges="orientation|screenSize" means whenever screen orientation will be changed a following method in Activity class will be called.

  @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        if(newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) { body }
    }

This is nature of andorid that whenever screen orientation is changed whole lifecycle of activity runs again.

To save and restore some data. you can use following methods.

@Override
public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
    super.onSaveInstanceState(outState, outPersistentState);

    outState.putString("key","value");
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    String s = savedInstanceState.getString("key");

}

score 0 · Answer 3 · answered Mar 26 '16 at 18:42

Try changing

android:configChanges="orientation|keyboardHidden"

Into

android:configChanges="orientation|screenSize"

this should solve your problem, but it is not a efficient way, for a better option refer http://developer.android.com/training/basics/activity-lifecycle/recreating.html

Android App orientation change restarts activity

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