我写了一个相机应用程序，但是当我想显示相机的实时预览时（在拍照之前），预览旋转了 90 度！这是我的相机活动代码：
public class CameraActivity extends Activity{
public static final int MEDIA_TYPE_IMAGE = 1 ;
private Camera mCamera;
private CameraPreview mPreview;
Uri photoPath ;
protected void onStop()
{
super.onStop();
mCamera.release();
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
// Create an instance of Camera
mCamera = getCameraInstance();
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
ViewGroup.LayoutParams previewParam = preview.getLayoutParams() ;
Parameters cameraParam = mCamera.getParameters() ;
double ratio = (double)cameraParam.getPictureSize().height / (double)cameraParam.getPictureSize().width ;
// previewParam.height= cameraParam.getPictureSize().height / 5 ;
// previewParam.width = cameraParam.getPictureSize().width / 5 ;
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
try
{
display.getSize(size);
}
catch(java.lang.NoSuchMethodError ignore)
{
size.x = display.getWidth();
size.y = display.getHeight() ;
}
int width = size.x;
int height = size.y;
previewParam.width = width;
previewParam.height = (int)(previewParam.width * ratio) ;
// preview.setLayoutParams(previewParam) ;
preview.addView(mPreview);
}
//Camera Classes here
private final static String TAG = "Navid";
public static Camera getCameraInstance()
{
Camera c = null ;
try
{
c = Camera.open() ;
}
catch(Exception e)
{
}
return c ;
}
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback
{
private SurfaceHolder mHolder ;
private Camera mCamera;
public CameraPreview(Context context , Camera camera)
{
super(context) ;
mCamera = camera ;
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder)
{
try
{
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
}
catch(IOException e)
{
Log.d(TAG,"Camera Preview Failed!: "+e.getMessage());
}
}
public void surfaceChanged(SurfaceHolder holder , int m , int n , int w)
{
}
public void surfaceDestroyed(SurfaceHolder holder)
{
}
}
private static File getOutputMediaFile(int type){
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyCameraApp");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
}else {
return null;
}
return mediaFile;
}
//save the picture here
private PictureCallback mPicture = new PictureCallback() {
// public final static int MEDIA_TYPE_IMAGE = 1 ;
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
photoPath = Uri.fromFile(pictureFile);
if (pictureFile == null){
Log.d("Errore Doorbin", "Error creating media file, check storage permissions: ");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
// these lines are for the gallery to scan the SDCard manually
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyCameraApp");
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
Uri.parse("file://"+ mediaStorageDir)));
// photoPath = Uri.fromFile(mediaStorageDir) ;
/* MediaScannerConnection.scanFile(CameraActivity.this,
new String[] { fos.toString() }, null,
new MediaScannerConnection.OnScanCompletedListener() {
public void onScanCompleted(String path, Uri uri) {
// code to execute when scanning is complete
}
});*/
// fos.close();
} catch (FileNotFoundException e) {
Log.d("Errore Doorbin", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("Errore Doorbin", "Error accessing file: " + e.getMessage());
}
catch (Exception e)
{
Log.d("Errore Doorbin", "errore Kolli dade!" + e.getMessage()) ;
}
}
};
public void capture(View v)
{
//mCamera.takePicture(null, null, mPicture);
//mCamera.release();
//mCamera = getCameraInstance() ;
//mCamera.startPreview();
TakePictureTask takePicture = new TakePictureTask() ;
takePicture.execute() ;
}
public void accept(View v)
{
Intent data = new Intent() ;
data.setData(photoPath) ;
setResult(RESULT_OK, data);
finish() ;
}
public void retake(View v)
{
Button button = (Button)findViewById(R.id.button_accept);
button.setVisibility(View.GONE);
button = (Button)findViewById(R.id.button_capture) ;
button.setVisibility(View.VISIBLE) ;
button = (Button)findViewById(R.id.button_retake);
button.setVisibility(View.GONE) ;
mCamera.startPreview();
}
/**
* A pretty basic example of an AsyncTask that takes the photo and
* then sleeps for a defined period of time before finishing. Upon
* finishing, it will restart the preview - Camera.startPreview().
*/
private class TakePictureTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPostExecute(Void result) {
// This returns the preview back to the live camera feed
Button button = (Button)findViewById(R.id.button_accept) ;
button.setVisibility(View.VISIBLE) ;
button = (Button)findViewById(R.id.button_retake) ;
button.setVisibility(View.VISIBLE);
button = (Button)findViewById(R.id.button_capture);
button.setVisibility(View.GONE);
//mCamera.startPreview();
}
@Override
protected Void doInBackground(Void... params) {
mCamera.takePicture(null, null, mPicture);
// Sleep for however long, you could store this in a variable and
// have it updated by a menu item which the user selects.
try {
Thread.sleep(3000); // 3 second preview
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
}
在我的应用程序清单中，我已将此活动方向更改为纵向！
问题是什么 ？为什么会这样？