Camera API-人像图像另存为风景

Question

I have tried to save and populate an image from the camera intent and populate the image into the ImageView. I tried to take a landscape picture and it worked well. The image is populated in the ImageView in landscape. However the problem arise when I tried to take a picture in portrait in the camera intent. The image preview before saving was still in portrait but when the results was returned to my ImageView, the image is in landscape.

Below is the code i used.

private ContentValues values;
    private Uri imageUri;
    private final int PICTURE_RESULT = 1;
    private Bitmap thumbnail;
    private String imageurl;
btn_takeImage.setOnClickListener(new OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
//              Intent camera_intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
//              startActivityForResult(camera_intent, CAMERA_PIC_REQUEST);

                values = new ContentValues();
                values.put(MediaStore.Images.Media.TITLE, "New Picture");
                values.put(MediaStore.Images.Media.DESCRIPTION, "From your Camera");
                imageUri = getContentResolver().insert(
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(intent, PICTURE_RESULT);
            }
        });
@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {

        case PICTURE_RESULT:
            if (requestCode == PICTURE_RESULT)
                if (resultCode == Activity.RESULT_OK) {
                    try {
                        thumbnail = MediaStore.Images.Media.getBitmap(
                                getContentResolver(), imageUri);
                        img_backgroundImage.setImageBitmap(thumbnail);
                        imageurl = getRealPathFromURI(imageUri);    
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                }
        }
    }

Answer 1

From the docs of Camera.Parameters#setRotation()

If applications want to rotate the picture to match the orientation of what users see, apps should use OrientationEventListener and Camera.CameraInfo

public void onOrientationChanged(int orientation) {
    if (orientation == ORIENTATION_UNKNOWN) return;
    android.hardware.Camera.CameraInfo info =
        new android.hardware.Camera.CameraInfo();
    android.hardware.Camera.getCameraInfo(cameraId, info);
    orientation = (orientation + 45) / 90 * 90;
    int rotation = 0;
    if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
        rotation = (info.orientation - orientation + 360) % 360;
    } else {  // back-facing camera
        rotation = (info.orientation + orientation) % 360;
    }
    mParameters.setRotation(rotation);
}

OrientationEventListener is an abstract class that contains the onOrientationChanged(). This method will receive orientation changes from the system. This is one possible implementation:

OrientationEventListener listener = new OrientationEventListener(this,
        SensorManager.SENSOR_DELAY_NORMAL) {

    @Override
    public void onOrientationChanged(int i) {
       //Code from above goes here.
    }
};
listener.enable();