快速旋转手机180度，摄像头预览翻转。

Question

我有一个自定义相机应用程序。当我将手机旋转90度时，相机预览正常工作。但是当我快速旋转手机180度时，相机预览会倒置。是否有解决方案...

以下是我的代码：

public class CustomCameraActivity extends Activity implements
    SurfaceHolder.Callback {

Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;
LayoutInflater controlInflater = null;
private Sensor mOrientaion1;
int cameraId = 0;
public final String TAG = "CustomCamera";
private SensorManager sensorManager;

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

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.main);

    context = this;

    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    mOrientaion1 = sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);

    // setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

    imageView = (ImageView) findViewById(R.id.imgError);

    getWindow().setFormat(PixelFormat.UNKNOWN);
    surfaceView = (SurfaceView) findViewById(R.id.camerapreview);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    controlInflater = LayoutInflater.from(getBaseContext());
    View viewControl = controlInflater.inflate(R.layout.custom, null);
    LayoutParams layoutParamsControl = new LayoutParams(
            LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);

    Button btn1 = (Button) viewControl.findViewById(R.id.Button01);
    Button btn2 = (Button) viewControl.findViewById(R.id.Button02);

    btn1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // Toast.makeText(context, "1111111111111111111111111",
            // Toast.LENGTH_SHORT).show();
            camera.takePicture(null, null, mPicture);

            Constant.rotationValueForCamera = Constant.rotationValue;
        }
    });

    btn2.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // Toast.makeText(context, "22222222222222222222222222",
            // Toast.LENGTH_SHORT).show();
            Log.e("0 imagePickerStatus", Constant.imagePickerStatus + "");

            Constant.imagePickerStatus = 0;

            Log.e("0 imagePickerStatus", Constant.imagePickerStatus + "");

            finish();
        }
    });

    this.addContentView(viewControl, layoutParamsControl);

    int ot = getResources().getConfiguration().orientation;

    if (Configuration.ORIENTATION_LANDSCAPE == ot) {
        imageView.setVisibility(View.GONE);
        Log.e("ori1111", "land");
    } else {
        imageView.setVisibility(View.VISIBLE);
        Log.e("ori111", "port");
    }
}

@Override
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();
        findViewById(R.id.Button01).setVisibility(View.VISIBLE);
        findViewById(R.id.Button02).setVisibility(View.VISIBLE);
        imageView.setVisibility(View.GONE);
        Log.e("ori", "land");
    } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {
        // Toast.makeText(this, "portrait", Toast.LENGTH_SHORT).show();
        findViewById(R.id.Button01).setVisibility(View.INVISIBLE);
        findViewById(R.id.Button02).setVisibility(View.INVISIBLE);
        imageView.setVisibility(View.VISIBLE);
        Log.e("ori", "port");
    }
}

public String getPollDeviceAttitude() {

    return Constant.rotationValueForCamera;
}

private SensorEventListener sensorEventListener = new SensorEventListener() {

    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
};

protected void onPause() {
    super.onPause();

    sensorManager.unregisterListener(sensorEventListener);

}

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

    sensorManager.registerListener(sensorEventListener,
            sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
            SensorManager.SENSOR_DELAY_NORMAL);
    sensorManager.registerListener(sensorEventListener,
            sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
            SensorManager.SENSOR_DELAY_NORMAL);
    sensorManager.registerListener(sensorEventListener,
            sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION),
            SensorManager.SENSOR_DELAY_NORMAL);

    if (Constant.isCapturedOk) {
        Constant.isCapturedOk = false;

        finish();
    }

}

PictureCallback mPicture = new PictureCallback() {
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        Log.e("Camrera", "22222222222222222");
        BitmapFactory.Options bfo = new BitmapFactory.Options();
        bfo.inDither = false;
        // bfo.inJustDecodeBounds = true;
        bfo.inPurgeable = true;
        bfo.inTempStorage = new byte[16 * 1024];

        Intent intent = new Intent(context, PreviewActivity.class);
        // intent.putExtra("data", data);
        Bitmap bitmapPicture = BitmapFactory.decodeByteArray(data, 0,
                data.length, bfo);
        Matrix matrix = new Matrix();
        if (Constant.result == 180) {
            matrix.postRotate(270);
        }
        if (Constant.result == 270) {
            matrix.postRotate(180);
        }
        int height = bitmapPicture.getHeight();
        int width = bitmapPicture.getWidth();
        Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmapPicture,
                height, width, true);
        Bitmap rotatedBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,
                scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix,
                true);
        ByteArrayOutputStream blob = new ByteArrayOutputStream();
        Log.e("Camrera1", "22222222222222222");
        rotatedBitmap.compress(CompressFormat.JPEG,
                50 /* ignored for PNG */, blob);
        byte[] bitmapdata = blob.toByteArray();
        Constant.imageData = bitmapdata;
        Log.e("Camrera2", "22222222222222222");
        startActivity(intent);

    }
};
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    if (previewing) {
        camera.stopPreview();
        previewing = false;
    }

    if (camera != null) {
        try {
            camera.setPreviewDisplay(holder);
            camera.startPreview();
            setCameraDisplayOrientation(this, cameraId, camera);
            previewing = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public static void setCameraDisplayOrientation(Activity activity,
        int cameraId, android.hardware.Camera camera) {
    android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
    android.hardware.Camera.getCameraInfo(cameraId, info);
    int rotation = activity.getWindowManager().getDefaultDisplay()
            .getRotation();
    int degrees = 0;
    switch (rotation) {
    case Surface.ROTATION_0:
        degrees = 0;
        Constant.result = 0;
        break;
    case Surface.ROTATION_90:
        degrees = 90;
        Constant.result = 90;
        break;
    case Surface.ROTATION_180:
        degrees = 180;
        Constant.result = 180;
        break;
    case Surface.ROTATION_270:
        degrees = 270;
        Constant.result = 270;
        break;
    }

    int result;
    if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
        result = (info.orientation + degrees) % 360;
        result = (360 - result) % 360; // compensate the mirror
    } else { // back-facing
        result = (info.orientation - degrees + 360) % 360;
    }
    camera.setDisplayOrientation(result);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    camera = Camera.open();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    camera.stopPreview();
    camera.release();
    camera = null;
    previewing = false;
}

@Override
protected void onStop() {
    super.onStop();

    Log.e("Tab", "Stoping");
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_BACK) {

        return true;

    }
    return super.onKeyDown(keyCode, event);

}

}

- Mohammad Rajob

---

@Nikola，那么这个问题没有解决方案吗？ - Mohammad Rajob

也许，我只是认为这与你的代码无关。 - Nikola

请查看此线程：https://dev59.com/IGct5IYBdhLWcg3wetYo - Alex Cohn

可能是相机直接快速旋转的重复问题。 - Alex Cohn

当你快速从横屏旋转到另一个横屏方向时，你是否会接收到surfaceChanged()回调？ - Alex Cohn

Answer 1

你可以使用OrientationEventListener来触发相机旋转的重新计算。

将其添加到你的活动中：

private OrientationEventListener orientationListener = null;

到 onCreate() 方法：

orientationListener = new OrientationEventListener(this) {
    public void onOrientationChanged(int orientation) {
        setCameraDisplayOrientation(CustomCameraActivity.this, cameraId, camera);
    }
};

到surfaceCreated()：

orientationListener.enable();

至于surfaceDestroyed()：

orientationListener.disable();

现在，它几乎可以工作了。为了使setCameraDisplayOrientation()更加健壮，

1. 添加camera != null的检查
2. 只有在result自上次调用函数以来发生了改变时，才调用camera.setDisplayOrientation(result)（或执行任何重要操作）。

- Alex Cohn

---

非常感谢。你的帮助让我无言以对。现在它可以正常工作了。 - Mohammad Rajob

我不喜欢这个解决方案。系统会重新启动您的活动并中断相机输出。我更喜欢设置固定的横向活动方向，并仅操作UI来模拟布局旋转（这就是原生相机应用程序的编写方式）。 - Alex Cohn

只是补充一下：我必须在onPause()中执行'orientationListener.disable();'，因为onDestroy会稍后调用一些毫秒（如果您按电源键，则根本不会被调用）。所以我遇到的错误是：旋转90度->主页按钮->旋转到0度->返回应用程序->错误的旋转。 - Patrick

@for3st：请注意，该示例使用的是SurfaceHolder.Callback.surfaceDestroyed()而不是Activity.onDestroy()。 - Alex Cohn

@for3st：如果你仍然需要它（用于视频处理或录制），那么保持相机运行并显示黑屏是可以的（在按下电源按钮后）。但是，如果你不使用它，最好在onPause()中释放它以节省电池。 - Alex Cohn

Answer 2

在声明所有活动的活动标签后，在Android清单文件中添加此行*

android:configChanges="keyboardHidden|orientation|screenSize"

like:

<activity android:name="com.geeklabs.ActivityMain"
            android:configChanges="keyboardHidden|orientation|screenSize" />

也许这会帮助你。

- Shailendra Madda