Question

我正在开发一款应用，并在8.1设备（Pixel2，Nexus5x）上遇到了一个奇怪的行为，所以我写了一个小应用来验证这种行为。

当MainActivity被锁定为portrait时，

LandscapeActivity被锁定为landscape模式。 MainActivity为结果LandscapeActivity启动。屏幕按预期从portrait切换到landscape。完成LandscapeActivity后，它会将结果传播到MainActivity，同时切换回portrait（按预期方式）。

但有时我会遇到一种错误。在onActivityResult MainActivity之后，它会从portrait切换到landscape以立即切换回portrait。虽然我可以处理这个州，但它仍然看起来很讨厌。

为了追溯，我会发布所有内容以重建它。

我该怎么做才能防止它？另请注意，每次都不会发生这种情况，并且只能在8.1设备上进行测试。在8.1以下的Android设备上似乎很好。

修改在我的清单中添加了android:configChanges="orientation|screenSize" @Floern在他的回答中没有成功。对平台错误的确认也是可接受的答案

清单

<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=".MainActivity"
            android:screenOrientation="portrait"
            android:configChanges="orientation|screenSize">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

    </application>

MainActivity

public class MainActivity extends AppCompatActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    private static final int REQ_CODE = 878;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate: savedInstanceState=" + savedInstanceState + ", orientation=" + orientation());
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, LandscapeActivity.class);
                startActivityForResult(intent, REQ_CODE);

            }
        });
    }

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

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

    @Override
    protected void onStart() {
        Log.d(TAG, "onStart: orientation=" + orientation());
        super.onStart();
    }

    @Override
    protected void onStop() {
        Log.d(TAG, "onStop: orientation=" + orientation());
        super.onStop();
    }

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

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.d(TAG, "onActivityResult: orientation=" + orientation());
        if (requestCode == REQ_CODE){
            Toast.makeText(this, "Result=" + data.getStringExtra(LandscapeActivity.KEY_DATA), Toast.LENGTH_LONG).show();
        }
    }

    String orientation(){
        return getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ?  "Landscape" : "Portrait";
    }
}

LandscapeActivity

public class LandscapeActivity extends AppCompatActivity{

    public static final String TAG = LandscapeActivity.class.getSimpleName();

    public static final String KEY_DATA = "DATA";
    static int COUNTER = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate: savedInstanceState=" + savedInstanceState + "orientation=" + (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ?  "Landscape" : "Portrait"));
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent data = new Intent();
                COUNTER++;
                data.putExtra(KEY_DATA, "Runned " + COUNTER + " times");
                setResult(RESULT_OK, data);
                finish();
            }
        });
    }

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

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

    @Override
    protected void onStart() {
        Log.d(TAG, "onStart: orientation=" + orientation());
        super.onStart();
    }

    @Override
    protected void onStop() {
        Log.d(TAG, "onStop: orientation=" + orientation());
        super.onStop();
    }

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

    String orientation(){
        return getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ?  "Landscape" : "Portrait";
    }
}

的build.gradle

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "android.example.com.orientationtest8_1"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

布局activity_main文件：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="android.dermalog.com.orientationtest8_1.MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

最后一个日志点击按钮重复：

01-04 15:18:06.744  D/MainActivity: onCreate: savedInstanceState=null
01-04 15:18:06.847  D/MainActivity: onStart: orientation=Portrait
01-04 15:18:06.850  D/MainActivity: onResume: orientation=Portrait
01-04 15:18:14.036  D/MainActivity: onPause: orientation=Portrait
01-04 15:18:14.108  D/LandscapeActivity: onCreate: savedInstanceState=nullorientation=Landscape
01-04 15:18:14.139  D/LandscapeActivity: onStart: orientation=Landscape
01-04 15:18:14.141  D/LandscapeActivity: onResume: orientation=Landscape
01-04 15:18:14.217  D/MainActivity: onStop: orientation=Portrait
01-04 15:18:15.643  D/LandscapeActivity: onPause: orientation=Landscape
01-04 15:18:15.711  D/MainActivity: onActivityResult: orientation=Portrait
01-04 15:18:15.719  D/MainActivity: onStart: orientation=Portrait
01-04 15:18:15.720  D/MainActivity: onResume: orientation=Portrait
01-04 15:18:15.786  D/LandscapeActivity: onStop: orientation=Landscape
01-04 15:18:15.786  D/LandscapeActivity: onDestroy: orientation=Landscape
01-04 15:18:18.036  D/MainActivity: onPause: orientation=Portrait
01-04 15:18:18.097  D/LandscapeActivity: onCreate: savedInstanceState=nullorientation=Landscape
01-04 15:18:18.121  D/LandscapeActivity: onStart: orientation=Landscape
01-04 15:18:18.123  D/LandscapeActivity: onResume: orientation=Landscape
01-04 15:18:18.213  D/MainActivity: onStop: orientation=Portrait
01-04 15:18:19.505  D/LandscapeActivity: onPause: orientation=Landscape
01-04 15:18:19.564  D/MainActivity: onActivityResult: orientation=Portrait
01-04 15:18:19.569  D/MainActivity: onStart: orientation=Portrait
01-04 15:18:19.569  D/MainActivity: onResume: orientation=Portrait
01-04 15:18:19.639  D/LandscapeActivity: onStop: orientation=Landscape
01-04 15:18:19.640  D/LandscapeActivity: onDestroy: orientation=Landscape
01-04 15:18:20.102  D/MainActivity: onPause: orientation=Portrait
01-04 15:18:20.103  D/MainActivity: onStop: orientation=Portrait
01-04 15:18:20.104  D/MainActivity: onDestroy: orientation=Portrait
01-04 15:18:20.123  D/MainActivity: onCreate: savedInstanceState=Bundle[{android:viewHierarchyState=Bundle[{android:views={16908290=android.view.AbsSavedState$1@7ceec3, 2131165191=android.support.v7.widget.Toolbar$SavedState@3c34340, 2131165193=android.view.AbsSavedState$1@7ceec3, 2131165199=android.view.AbsSavedState$1@7ceec3, 2131165219=android.view.AbsSavedState$1@7ceec3, 2131165229=android.view.AbsSavedState$1@7ceec3}}], android:lastAutofillId=1073741823, android:fragments=android.app.FragmentManagerState@c215279}]
01-04 15:18:20.149  D/MainActivity: onStart: orientation=Landscape
01-04 15:18:20.152  D/MainActivity: onResume: orientation=Landscape
01-04 15:18:20.699  D/MainActivity: onPause: orientation=Landscape
01-04 15:18:20.701  D/MainActivity: onStop: orientation=Landscape
01-04 15:18:20.702  D/MainActivity: onDestroy: orientation=Landscape
01-04 15:18:20.718  D/MainActivity: onCreate: savedInstanceState=Bundle[{android:viewHierarchyState=Bundle[{android:views={16908290=android.view.AbsSavedState$1@7ceec3, 2131165191=android.support.v7.widget.Toolbar$SavedState@807af46, 2131165193=android.view.AbsSavedState$1@7ceec3, 2131165199=android.view.AbsSavedState$1@7ceec3, 2131165219=android.view.AbsSavedState$1@7ceec3, 2131165229=android.view.AbsSavedState$1@7ceec3}}], android:lastAutofillId=1073741823, android:fragments=android.app.FragmentManagerState@8d12507}]
01-04 15:18:20.748  D/MainActivity: onStart: orientation=Portrait
01-04 15:18:20.751  D/MainActivity: onResume: orientation=Portrait

Answer 1

此bug已修复。所以等待下一个版本/补丁。

Answer 2

是的，这是Android 8.1 OS版本中的问题。由于这已经过时了。我们可以解决这些问题。在此特定的API级别中，Android OS可能会存储最新的方向值并将其应用于所有屏幕，直到上一个屏幕或该特定屏幕被破坏为止。因此，解决此类问题的方法是在返回屏幕之前更改方向。
例如：
如果ScreenA处于纵向模式，而ScreenB处于横向模式，并且如果将屏幕移至“横向”的ScreenB，并且如果您返回到ScreenA而又不杀死ScreenB（还原ScreenA），则ScreenA在“横向”中也是可见的。
要解决此问题，请在ScreenB的 onPause（）或 OnStop（）中强制将ScreenA的方向更改为纵向（以还原ScreenA）。

 if (android.os.Build.VERSION.SDK_INT >= 27) {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

此呼叫后，ScreenA将处于纵向状态。另外，在ScreenB的onResume（）中，

if (android.os.Build.VERSION.SDK_INT >= 27) {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
}

Answer 3

这可能确实是一个框架错误。我注意到三星设备上的类似行为，同时使用相机应用程序（通过Intent）从仅限纵向应用程序的横向。我无法弄清楚究竟是什么原因，但我找到了一种可以最大限度地减少影响的解决办法。

如果您告诉系统要自行处理方向更改，可以在活动中添加android:configChanges="orientation|screenSize"，但不会在方向更改时重新创建。因此，您可以避免重新创建活动（两次）的开销，这可能会提高性能，直到您根本没有注意到方向更改。

<activity android:name=".MainActivity"
    android:screenOrientation="portrait"
    android:configChanges="orientation|screenSize">

如何在Android 8.1版本设备上完成活动时阻止屏幕方向更改？

3 个答案: