ローテーションAndroidでのアクティビティの再起動

https://stackoverflow.com/questions/456211

19-08-2019
|

質問

Androidアプリケーションで、デバイスを回転させる（キーボードをスライドさせる）と、Activityが再起動されます（onCreateが呼び出されます）。さて、これはおそらくそうなっているはずですが、私は<=>メソッドで多くの初期設定を行うので、次のいずれかが必要です：

すべての初期設定を別の関数に入れて、デバイスの回転やすべての失われないようにします
再度<=>が呼び出されず、レイアウトが調整されるようにするか、
アプリをポートレートに制限して、<=>が呼び出されないようにします。

解決

アプリケーションクラスの使用

初期化で行っていることに応じて、Applicationを拡張する新しいクラスを作成し、そのクラス内のオーバーライドされたonCreateメソッドに初期化コードを移動することを検討できます。

public class MyApplicationClass extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    // TODO Put your application initialization code here.
  }
}

アプリケーションクラス内のandroid:configChangesは、アプリケーション全体が作成されたときにのみ呼び出されるため、アクティビティは方向を指定して再起動するか、キーボードの可視性の変更によってトリガーされません。

このクラスのインスタンスをシングルトンとして公開し、ゲッターとセッターを使用して初期化するアプリケーション変数を公開することをお勧めします。

注：登録および使用するには、マニフェストで新しいApplicationクラスの名前を指定する必要があります。

<application
    android:name="com.you.yourapp.MyApplicationClass"

設定変更への対応 [更新：これはAPI 13以降廃止されています。推奨される代替案を見る]

さらに別の方法として、再起動を引き起こすイベントをアプリケーションにリッスンさせることができます<！>＃8211;方向やキーボードの可視性の変更など<！>＃8211;アクティビティ内で処理します。

onConfigurationChangedノードをアクティビティのマニフェストノードに追加することから始めます

 <activity android:name=".MyActivity"
      android:configChanges="orientation|keyboardHidden"
      android:label="@string/app_name">

または Android 3.2（APIレベル13）以降：

<activity android:name=".MyActivity"
      android:configChanges="keyboardHidden|orientation|screenSize"
      android:label="@string/app_name">

次に、アクティビティ内でsetContentViewメソッドをオーバーライドし、<=>を呼び出して、GUIレイアウトを新しい方向で強制的に再実行します。

@Override
public void onConfigurationChanged(Configuration newConfig) {
  super.onConfigurationChanged(newConfig);
  setContentView(R.layout.myLayout);
}

他のヒント

Android 3.2以降のアップデート：

注意：Android 3.2（APIレベル13）以降、 <！> quot;画面サイズ<！> quot;デバイスが縦向きと横向きを切り替えるときにも変化します。したがって、APIレベル13以上（minSdkVersionおよびtargetSdkVersion属性で宣言されているように）で開発するときの方向の変更によるランタイムの再起動を防止する場合は、"screenSize"値に加えて"orientation"値を含める必要があります。つまり、android:configChanges="orientation|screenSize"を宣言する必要があります。ただし、アプリケーションがAPIレベル12以下を対象とする場合、アクティビティは常にこの構成変更自体を処理します（Android 3.2以降のデバイスで実行している場合でも、この構成変更はアクティビティを再起動しません）。

onCreate()の完全な実行を停止する代わりに、イベントに渡されるBundle savedInstanceStateをチェックして、nullかどうかを確認してください。

たとえば、すべての方向の変更ではなく、Activityが本当に作成されたときに実行するロジックがある場合、<=>がnullの場合にのみ<=>でそのロジックを実行します。

それ以外の場合、レイアウトが向きに合わせて適切に再描画されるようにします。

public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_game_list);

        if(savedInstanceState == null){
            setupCloudMessaging();
        }
}

これが究極の答えかどうかはわかりませんが、私にとってはうまくいきます。

私がしたこと...

マニフェストのアクティビティセクションに追加：

android:configChanges="keyboardHidden|orientation"

アクティビティのコードに実装：

//used in onCreate() and onConfigurationChanged() to set up the UI elements
public void InitializeUI()
{
    //get views from ID's
    this.textViewHeaderMainMessage = (TextView) this.findViewById(R.id.TextViewHeaderMainMessage);

    //etc... hook up click listeners, whatever you need from the Views
}

//Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    InitializeUI();
}

//this is called when the screen rotates.
// (onCreate is no longer called when screen rotates due to manifest, see: android:configChanges)
@Override
public void onConfigurationChanged(Configuration newConfig)
{
    super.onConfigurationChanged(newConfig);
    setContentView(R.layout.main);

    InitializeUI();
}

説明するのはデフォルトの動作です。以下を追加して、これらのイベントを自分で検出して処理する必要があります。

android:configChanges

マニフェストに追加してから、処理する変更を追加します。したがって、オリエンテーションには、次を使用します。

android:configChanges="orientation"

およびキーボードを開いたり閉じたりするには、次を使用します：

android:configChanges="keyboardHidden"

両方を処理する場合は、次のようなパイプコマンドを使用してそれらを分離できます。

android:configChanges="keyboardHidden|orientation"

これにより、呼び出すActivityでonConfigurationChangedメソッドがトリガーされます。メソッドをオーバーライドする場合、新しい値を渡すことができます。

これがお役に立てば幸いです。

この伝承を発見しました：

方向の変更を通じてアクティビティを維持し、onConfigurationChanged、ドキュメントおよび上記のコードサンプルマニフェストファイルでこれを提案します：

<activity android:name=".MyActivity"
      android:configChanges="orientation|keyboardHidden"
      android:label="@string/app_name">

常に機能するという追加の利点があります。

ボーナスの伝承は、keyboardHiddenを省略することは論理的に見えるかもしれませんが、エミュレーターで障害が発生することです（少なくともAndroid 2.1の場合）：orientationのみを指定すると、エミュレーターはOnCreateと<=>の両方を呼び出します時々、そして<=>他の時間だけ。

デバイスでエラーが発生したことはありませんが、エミュレーターが他のデバイスで失敗したという話を聞きました。したがって、文書化する価値があります。

You might also consider using the Android platform's way of persisting data across orientation changes: onRetainNonConfigurationInstance() and getLastNonConfigurationInstance().

This allows you to persist data across configuration changes, such as information you may have gotten from a server fetch or something else that's been computed in onCreate or since, while also allowing Android to re-layout your Activity using the xml file for the orientation now in use.

See here or here.

It should be noted that these methods are now deprecated (although still more flexible than handling orientation change yourself as most of the above solutions suggest) with the recommendation that everyone switch to Fragments and instead use setRetainInstance(true) on each Fragment you want to retain.

The approach is useful but is incomplete when using Fragments.

Fragments usually get recreated on configuration change. If you don't wish this to happen, use

setRetainInstance(true); in the Fragment's constructor(s)

This will cause fragments to be retained during configuration change.

http://developer.android.com/reference/android/app/Fragment.html#setRetainInstance(boolean)

I just simply added

     android:configChanges="keyboard|keyboardHidden|orientation"

in the manifest file and did not add any onConfigurationChanged method in my activity.

So every time the keyboard slides out or in nothing happens.

The onCreate method is still called even when you change the orientation of android. So moving all the heavy functionality to this method is not going to help you

It is very simple just do the following steps:

<activity
    android:name=".Test"
    android:configChanges="orientation|screenSize"
    android:screenOrientation="landscape" >
</activity>

This works for me :

Note: orientation depends on your requitement

Put the code below inside your <activity> tag in Manifest.xml:

android:configChanges="screenLayout|screenSize|orientation"

 onConfigurationChanged is called when the screen rotates. 
 (onCreate is no longer called when screen rotates due to manifest, see:  
 android:configChanges)

What part of the manifest tells it "don't call onCreate()"?

Also, Google's docs say to avoid using android:configChanges (except as a last resort).... But then the alternate methods they suggest all DO use android:configChanges.

It has been my experience that the emulator ALWAYS calls onCreate() upon rotation.
But the 1-2 devices that I run the same code on... do not. (Not sure why there would be any difference.)

Add this line to your manifest :-

android:configChanges="orientation|keyboard|keyboardHidden|screenSize|screenLayout|uiMode"

and this snippet to the activity :-

@Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
    }

Changes to be made in the Android manifest are:

android:configChanges="keyboardHidden|orientation"

Additions to be made inside activity are:

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

    // Checks the orientation of the screen
    if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
        Toast.makeText(this, "landscape", Toast.LENGTH_SHORT).show();
    } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {
        Toast.makeText(this, "portrait", Toast.LENGTH_SHORT).show();
    }
}

There are several ways to do this:

Save Activity State

You can save the activity state in onSaveInstanceState.

@Override
public void onSaveInstanceState(Bundle outState) {
    /*Save your data to be restored here
    Example : outState.putLong("time_state", time); , time is a long variable*/
    super.onSaveInstanceState(outState);
}

and then use the bundle to restore the state.

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

    if(savedInstanceState!= null){
       /*When rotation occurs
        Example : time = savedInstanceState.getLong("time_state", 0); */
    } else {
      //When onCreate is called for the first time
    }
}

Handle orientation changes by yourself

Another alternative is to handle the orientation changes by yourself. But this is not considered a good practice.

Add this to your manifest file.

android:configChanges="keyboardHidden|orientation"

for Android 3.2 and later:

android:configChanges="keyboardHidden|orientation|screenSize"

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

if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {
        //Handle rotation from landscape to portarit mode here
    } else if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE){
        //Handle rotation from portrait to landscape mode here
    }
}

Restrict rotation

You can also confine your activity to portrait or landscape mode to avoid rotation.

Add this to the activity tag in your manifest file:

        android:screenOrientation="portrait"

Or implement this programmatically in your activity:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

The way I have found to do this is use the onRestoreInstanceState and the onSaveInstanceState events to save something in the Bundle (even if you dont need any variables saved, just put something in there so the Bundle isn't empty). Then, on the onCreate method, check to see if the Bundle is empty, and if it is, then do the initialization, if not, then do it.

Even though it is not "the Android way" I have gotten very good results by handling orientation changes myself and simply repositioning the widgets within a view to take the altered orientation into account. This is faster than any other approach, because your views do not have to be saved and restored. It also provides a more seamless experience to the user, because the respositioned widgets are exactly the same widgets, just moved and/or resized. Not only model state, but also view state, can be preserved in this manner.

RelativeLayout can sometimes be a good choice for a view that has to reorient itself from time to time. You just provide a set of portrait layout params and a set of landscaped layout params, with different relative positioning rules on each, for each child widget. Then, in your onConfigurationChanged() method, you pass the appropriate one to a setLayoutParams() call on each child. If any child control itself needs to be internally reoriented, you just call a method on that child to perform the reorientation. That child similarly calls methods on any of its child controls that need internal reorientation, and so on.

Every time when screen is rotated, opened activity is finished and onCreate() is called again.

1 . You can do one thing save the state of activity when screen is rotated so that, You can recover all old stuff when activity's onCreate() is called again. Refer this link

2 . If you want to prevent restarting of the activity just place following lines in your manifest.xml file.

  <activity android:name=".Youractivity"
  android:configChanges="orientation|screenSize"/>

Note: I post this answer if someone in the future face the same problem as me. For me the following line wasn't enought:

android:configChanges="orientation"

When I rotated the screen, the method `onConfigurationChanged(Configuration newConfig) did't get called.

Solution: I also had to add "screenSize" even if the problem had to do with the orientation. So in the AndroidManifest.xml - file, add this:

android:configChanges="keyboardHidden|orientation|screenSize"

Then implement the method onConfigurationChanged(Configuration newConfig)

you need to use the onSavedInstanceState method to store all the value to its parameter is has that is bundle

@Override
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        super.onSaveInstanceState(outState, outPersistentState);
        outPersistentState.putBoolean("key",value);
    }

and use

@Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        savedInstanceState.getBoolean("key");
    }

to retrive and set the value to view objects it will handles the screen rotations

In the activity section of the manifest, add:

android:configChanges="keyboardHidden|orientation"

Add this line in manifest : android:configChanges="orientation|screenSize"

People are saying that you should use

android:configChanges="keyboardHidden|orientation"

But the best and most professional way to handle rotation in Android is to use the Loader class. It's not a famous class(I don't know why), but it is way better than the AsyncTask. For more information, you can read the Android tutorials found in Udacity's Android courses.

Of course, as another way, you could store the values or the views with onSaveInstanceState and read them with onRestoreInstanceState. It's up to you really.

After a while of trial and error, I found a solution which fits my needs in the most situations. Here is the Code:

Manifest configuration:

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

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

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

</manifest>

MainActivity:

import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String TAG = "MainActivity";

    private Fragment mFragment;

    private int mSelected = -1;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate  " + "");

        // null check not realy needed - but just in case...
        if (savedInstanceState == null) {

            initUi();

            // get an instance of FragmentTransaction from your Activity
            FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

            /*IMPORTANT: Do the INITIAL(!) transaction only once!
            * If we call this everytime the layout changes orientation,
            * we will end with a messy, half-working UI.
            * */
            mFragment = FragmentOne.newInstance(mSelected = 0);
            fragmentTransaction.add(R.id.frame, mFragment);
            fragmentTransaction.commit();
        }
    }


    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        Log.d(TAG, "onConfigurationChanged  " +
                   (newConfig.orientation
                    == Configuration.ORIENTATION_LANDSCAPE
                    ? "landscape" : "portrait"));

        initUi();

        Log.i(TAG, "onConfigurationChanged - last selected: " + mSelected);
        makeFragmentTransaction(mSelected);
    }


    /**
     * Called from {@link #onCreate} and {@link #onConfigurationChanged}
     */
    private void initUi() {
        setContentView(R.layout.activity_main);
        Log.d(TAG, "onCreate  instanceState == null / reinitializing..." + "");
        Button btnFragmentOne = (Button) findViewById(R.id.btn_fragment_one);
        Button btnFragmentTwo = (Button) findViewById(R.id.btn_fragment_two);
        btnFragmentOne.setOnClickListener(this);
        btnFragmentTwo.setOnClickListener(this);
    }


    /**
     * Not invoked (just for testing)...
     */
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Log.d(TAG, "onSaveInstanceState  " + "YOU WON'T SEE ME!!!");
    }


    /**
     * Not invoked (just for testing)...
     */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        Log.d(TAG, "onSaveInstanceState  " + "YOU WON'T SEE ME, AS WELL!!!");
    }


    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG, "onResume  " + "");
    }


    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "onPause  " + "");
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy  " + "");
    }


    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.btn_fragment_one:
                Log.d(TAG, "onClick btn_fragment_one " + "");
                makeFragmentTransaction(0);
                break;

            case R.id.btn_fragment_two:
                Log.d(TAG, "onClick btn_fragment_two " + "");
                makeFragmentTransaction(1);
                break;

            default:
                Log.d(TAG, "onClick  null - wtf?!" + "");
        }
    }


    /**
     * We replace the current Fragment with the selected one.
     * Note: It's called from {@link #onConfigurationChanged} as well.
     */
    private void makeFragmentTransaction(int selection) {

        switch (selection) {
            case 0:
                mFragment = FragmentOne.newInstance(mSelected = 0);
                break;
            case 1:
                mFragment = FragmentTwo.newInstance(mSelected = 1);
                break;
        }

        // Create new transaction
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

        // Replace whatever is in the fragment_container view with this fragment,
        // and add the transaction to the back stack
        transaction.replace(R.id.frame, mFragment);

        /*This would add the Fragment to the backstack...
        * But right now we comment it out.*/
        //        transaction.addToBackStack(null);

        // Commit the transaction
        transaction.commit();
    }

}

And sample Fragment:

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
 * @author Martin Pfeffer (pepperonas)
 */
public class FragmentOne extends Fragment {

    private static final String TAG = "FragmentOne";


    public static Fragment newInstance(int i) {
        Fragment fragment = new FragmentOne();
        Bundle args = new Bundle();
        args.putInt("the_id", i);
        fragment.setArguments(args);
        return fragment;
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Log.d(TAG, "onCreateView  " + "");
        return inflater.inflate(R.layout.fragment_one, container, false);
    }

}

Can be found on github.

Use orientation listener to perform different tasks on different orientation.

@Override
public void onConfigurationChanged(Configuration myConfig) 
{
    super.onConfigurationChanged(myConfig);
    int orient = getResources().getConfiguration().orientation; 
    switch(orient) 
    {
       case Configuration.ORIENTATION_LANDSCAPE:
          setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
                    break;
       case Configuration.ORIENTATION_PORTRAIT:
          setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
                    break;
       default:
          setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
    }
}

Put this below code in your Activity in Android Manifest.

android:configChanges="orientation"

This will not restart your activity when you would change orientation.

Fix the screen orientation (landscape or portrait) in AndroidManifest.xml

android:screenOrientation="portrait" or android:screenOrientation="landscape"

for this your onResume() method is not called.

One of the best component of android architechure introduce by google will fulfill your all the requirement that is ViewModel.

That is designed to store and manage UI related data in lifecycle way plus that will allow data to survive as screen rotates

class MyViewModel : ViewModel() {

Please refer this:https://developer.android.com/topic/libraries/architecture/viewmodel

You can lock to the current orientation of screen using this code...

int currentOrientation =context.getResources().getConfiguration().orientation;
        if (currentOrientation == Configuration.ORIENTATION_PORTRAIT) {
            ((Activity) context).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        } else {
            ((Activity) context). setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        }

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