MrNero
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Hi,
ich versuche Bilder in einem bestimmten Größenformat aufzunehmen über eine eigens angelegte CameraPreview und CameraActivity:
CameraActivity:
CameraPreview:
CameraActivity.Layout:
Wenn ich die Activity starte, sehe ich nur einen weißen Hintergrund und den Button. Beim Aufruf der Methode:
"mCamera.setPreviewDisplay(mHolder);"
..bekomme ich die Meldung (app passed null surface).
Das heißt wahrscheinlich soviel wie das SurfaceView Null ist, aber ich erstelle es doch explizit und prüfe anschließend sogar noch ob es Null ist. Woran könnte das liegen?
Logcat:
12-16 13:09:39.941: I/CameraActivity.onCreate()(439): mCamera initialized
12-16 13:09:39.941: I/CameraPreview.constructor(...)(439): mSurfaceView initialized
12-16 13:09:39.941: I/CameraPreview.constructor(...)(439): mHolder setup
12-16 13:09:39.941: I/CameraActivity.onCreate()(439): mPreview initialized
12-16 13:09:39.952: I/CameraActivity.onCreate()(439): mPreview added to FrameLayout
12-16 13:09:39.952: I/CameraPreview.setCamera()(439): stopPreviewAndFreeCamera()
12-16 13:09:39.952: I/CameraPreview.setCamera()(439): setup new Camera
12-16 13:09:39.961: D/Camera(439): app passed NULL surface
12-16 13:09:39.961: I/CameraPreview.setCamera()(439): mCamera.setPreviewDisplay(mHolder)
12-16 13:09:39.971: I/CameraPreview.setCamera()(439): mCamera.startPreview()
12-16 13:09:39.971: I/CameraActivity.onCreate()(439): mPreview.setCamera(mCamera)
12-16 13:09:40.622: I/ActivityManager(60): Displayed com.example.popup/.CameraActivity: +810ms
ich versuche Bilder in einem bestimmten Größenformat aufzunehmen über eine eigens angelegte CameraPreview und CameraActivity:
CameraActivity:
Code:
public class CameraActivity extends Activity {
private Camera mCamera;
private Preview mPreview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
// Create an instance of Camera
mCamera = Camera.open(0); if(mCamera !=null) Log.i("CameraActivity.onCreate()", "mCamera initialized");
// Create our Preview view and set it as the content of our activity.
mPreview = new Preview(this); if(mPreview !=null) Log.i("CameraActivity.onCreate()", "mPreview initialized");
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview); Log.i("CameraActivity.onCreate()", "mPreview added to FrameLayout");
mPreview.setCamera(mCamera); Log.i("CameraActivity.onCreate()", "mPreview.setCamera(mCamera)");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_camera, menu);
return true;
}
@Override
public void onPause() {
super.onPause();
mPreview.stopPreviewAndFreeCamera();
}
}CameraPreview:
Code:
public class Preview extends ViewGroup implements SurfaceHolder.Callback {
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
private Camera mCamera;
List<Size> mSupportedPreviewSizes;
/**
* @param context
*/
public Preview(Context context) {
super(context);
mSurfaceView = new SurfaceView(context); Log.i("CameraPreview.constructor(...)", "mSurfaceView initialized");
if(mSurfaceView==null) {Log.i("CameraPreview.constructor(...)", "mSurfaceView is null");}
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder(); Log.i("CameraPreview.constructor(...)", "mHolder setup");
if(mHolder==null) {Log.e("PreviewCamera", "mHolder is null");}
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
/**
* @param context
* @param attrs
*/
public Preview(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
/**
* @param context
* @param attrs
* @param defStyle
*/
public Preview(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
}
/* (non-Javadoc)
* @see android.view.ViewGroup#onLayout(boolean, int, int, int, int)
*/
@Override
protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) {
// TODO Auto-generated method stub
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(width, height);
requestLayout();
mCamera.setParameters(parameters);
/*
Important: Call startPreview() to start updating the preview surface. Preview must be
started before you can take a picture.
*/
mCamera.startPreview(); Log.i("CameraPreview.surfaceChanged(...)", "mCamera.startPreview()");
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
/*
Call stopPreview() to stop updating the preview surface.
*/
mCamera.stopPreview(); Log.i("CameraPreview.surfaceDestroyed(...)", "mCamera.stopPreview()");
}
}
/**
* When this function returns, mCamera will be null.
*/
public void stopPreviewAndFreeCamera() {
if (mCamera != null) {
/*
Call stopPreview() to stop updating the preview surface.
*/
mCamera.stopPreview(); Log.i("CameraPreview.stopPreviewAndFreeCamera()", "mCamera.stopPreview()");
/*
Important: Call release() to release the camera for use by other applications.
Applications should release the camera immediately in onPause() (and re-open() it in
onResume()).
*/
mCamera.release(); Log.i("CameraPreview.stopPreviewAndFreeCamera()", "mCamera.release()");
mCamera = null;
}
}
/***
*
* @param camera
*/
public void setCamera(Camera camera) {
if (mCamera == camera) { Log.i("CameraPreview.setCamera()", "mCamera equals the Camera you want to set"); return; }
stopPreviewAndFreeCamera(); Log.i("CameraPreview.setCamera()", "stopPreviewAndFreeCamera()");
mCamera = camera; Log.i("CameraPreview.setCamera()", "setup new Camera");
if (mCamera != null) {
List<Size> localSizes = mCamera.getParameters().getSupportedPreviewSizes();
mSupportedPreviewSizes = localSizes;
requestLayout();
try {
mCamera.setPreviewDisplay(mHolder);
Log.i("CameraPreview.setCamera()", "mCamera.setPreviewDisplay(mHolder)");
} catch (IOException e) {
e.printStackTrace();
}
/*
Important: Call startPreview() to start updating the preview surface. Preview must
be started before you can take a picture.
*/
mCamera.startPreview(); Log.i("CameraPreview.setCamera()", "mCamera.startPreview()");
}
}
/***
*
* @param id
* @return
*/
public boolean safeCameraOpen(int id) {
boolean qOpened = false;
try {
releaseCameraAndPreview();
mCamera = Camera.open(id);
qOpened = (mCamera != null);
} catch (Exception e) {
// Log.e(R.string.app_name, "failed to open Camera");
e.printStackTrace();
}
return qOpened;
}
/**
*
*/
Camera.PictureCallback mPicCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// TODO Auto-generated method stub
Log.d("lala", "pic is taken");
}
};
/**
*
*/
public void takePic() {
// mCamera.takePicture(null, mPicCallback, mPicCallback);
}
/**
*
*/
private void releaseCameraAndPreview() {
this.setCamera(null);
if (mCamera != null) {
mCamera.release();
mCamera = null;
}
}
}CameraActivity.Layout:
Code:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CameraActivity" >
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="0dip"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
<Button
android:id="@+id/button_capture"
android:text="Capture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
/>
</LinearLayout>Wenn ich die Activity starte, sehe ich nur einen weißen Hintergrund und den Button. Beim Aufruf der Methode:
"mCamera.setPreviewDisplay(mHolder);"
..bekomme ich die Meldung (app passed null surface).
Das heißt wahrscheinlich soviel wie das SurfaceView Null ist, aber ich erstelle es doch explizit und prüfe anschließend sogar noch ob es Null ist. Woran könnte das liegen?
Logcat:
12-16 13:09:39.941: I/CameraActivity.onCreate()(439): mCamera initialized
12-16 13:09:39.941: I/CameraPreview.constructor(...)(439): mSurfaceView initialized
12-16 13:09:39.941: I/CameraPreview.constructor(...)(439): mHolder setup
12-16 13:09:39.941: I/CameraActivity.onCreate()(439): mPreview initialized
12-16 13:09:39.952: I/CameraActivity.onCreate()(439): mPreview added to FrameLayout
12-16 13:09:39.952: I/CameraPreview.setCamera()(439): stopPreviewAndFreeCamera()
12-16 13:09:39.952: I/CameraPreview.setCamera()(439): setup new Camera
12-16 13:09:39.961: D/Camera(439): app passed NULL surface
12-16 13:09:39.961: I/CameraPreview.setCamera()(439): mCamera.setPreviewDisplay(mHolder)
12-16 13:09:39.971: I/CameraPreview.setCamera()(439): mCamera.startPreview()
12-16 13:09:39.971: I/CameraActivity.onCreate()(439): mPreview.setCamera(mCamera)
12-16 13:09:40.622: I/ActivityManager(60): Displayed com.example.popup/.CameraActivity: +810ms
