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POAndroid - Front Camera Preview SurfaceView
 

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  1. POAndroid - Front Camera Preview SurfaceView
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    <p>I'm using the code below to show the front_camera inside a <code>surfaceView</code>, but when I try this code on a <strong>Samsung Galaxy S plus</strong>, all the screen is black, but no errors occur. Does anyone know why it happens?</p> <pre><code>public class TestLedActivity extends Activity { private SurfaceView preview=null; private SurfaceHolder previewHolder=null; private Camera camera=null; private boolean inPreview=false; private int id; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); int currentapiVersion = android.os.Build.VERSION.SDK_INT; if (currentapiVersion &gt; android.os.Build.VERSION_CODES.FROYO){ id=findFrontFacingCamera(); Log.d("TestLedActivity","L'id trovato e': "+id); camera = Camera.open(id); } else{ Log.d("TestLedActivity","La versione e' froyo"); camera = Camera.open(); } preview=(SurfaceView)findViewById(R.id.cpPreview); // TODO Auto-generated method stub previewHolder=preview.getHolder(); previewHolder.addCallback(surfaceCallback); previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } @Override public void onResume() { super.onResume(); } @Override public void onPause() { if (inPreview) { camera.stopPreview(); } camera.release(); camera=null; inPreview=false; super.onPause(); } private int findFrontFacingCamera() { int idCamera=0; // Look for front-facing camera, using the Gingerbread API. // Java reflection is used for backwards compatibility with pre-Gingerbread APIs. try { Class&lt;?&gt; cameraClass = Class.forName("android.hardware.Camera"); Object cameraInfo = null; Field field = null; int cameraCount = 0; Method getNumberOfCamerasMethod = cameraClass.getMethod( "getNumberOfCameras" ); if ( getNumberOfCamerasMethod != null ) { cameraCount = (Integer) getNumberOfCamerasMethod.invoke( null, (Object[]) null ); } Class&lt;?&gt; cameraInfoClass = Class.forName("android.hardware.Camera$CameraInfo"); if ( cameraInfoClass != null ) { cameraInfo = cameraInfoClass.newInstance(); } if ( cameraInfo != null ) { field = cameraInfo.getClass().getField( "facing" ); } Method getCameraInfoMethod = cameraClass.getMethod( "getCameraInfo", Integer.TYPE, cameraInfoClass ); if ( getCameraInfoMethod != null &amp;&amp; cameraInfoClass != null &amp;&amp; field != null ) { for ( int camIdx = 0; camIdx &lt; cameraCount; camIdx++ ) { getCameraInfoMethod.invoke( null, camIdx, cameraInfo ); int facing = field.getInt( cameraInfo ); if ( facing == 1 ) { // Camera.CameraInfo.CAMERA_FACING_FRONT try { Method cameraOpenMethod = cameraClass.getMethod( "open", Integer.TYPE ); if ( cameraOpenMethod != null ) { Log.d("TestLedActivity","Id frontale trovato: "+camIdx); //camera = (Camera) cameraOpenMethod.invoke( null, camIdx ); idCamera=camIdx; } } catch (RuntimeException e) { Log.e("TestLedActivity", "Camera failed to open: " + e.getLocalizedMessage()); } } } } } // Ignore the bevy of checked exceptions the Java Reflection API throws - if it fails, who cares. catch ( ClassNotFoundException e ) {Log.e("TestLedActivity", "ClassNotFoundException" + e.getLocalizedMessage());} catch ( NoSuchMethodException e ) {Log.e("TestLedActivity", "NoSuchMethodException" + e.getLocalizedMessage());} catch ( NoSuchFieldException e ) {Log.e("TestLedActivity", "NoSuchFieldException" + e.getLocalizedMessage());} catch ( IllegalAccessException e ) {Log.e("TestLedActivity", "IllegalAccessException" + e.getLocalizedMessage());} catch ( InvocationTargetException e ) {Log.e("TestLedActivity", "InvocationTargetException" + e.getLocalizedMessage());} catch ( InstantiationException e ) {Log.e("TestLedActivity", "InstantiationException" + e.getLocalizedMessage());} catch ( SecurityException e ) {Log.e("TestLedActivity", "SecurityException" + e.getLocalizedMessage());} if ( camera == null ) { Log.d("TestLedActivity","Devo aprire la camera dietro"); // Try using the pre-Gingerbread APIs to open the camera. idCamera=0; } return idCamera; } private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) { Camera.Size result=null; for (Camera.Size size : parameters.getSupportedPreviewSizes()) { if (size.width&lt;=width &amp;&amp; size.height&lt;=height) { if (result==null) { result=size; } else { int resultArea=result.width*result.height; int newArea=size.width*size.height; if (newArea&gt;resultArea) { result=size; } } } } return(result); } SurfaceHolder.Callback surfaceCallback=new SurfaceHolder.Callback() { public void surfaceCreated(SurfaceHolder holder) { try { camera.setPreviewDisplay(previewHolder); } catch (Throwable t) { Log.e("PreviewDemo-surfaceCallback", "Exception in setPreviewDisplay()", t); Toast .makeText(TestLedActivity.this, t.getMessage(), Toast.LENGTH_LONG) .show(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { Camera.Parameters parameters=camera.getParameters(); Camera.Size size=getBestPreviewSize(width, height, parameters); if (size!=null) { //parameters.set("camera-id", 0); parameters.setPreviewSize(size.width, size.height); camera.setParameters(parameters); camera.startPreview(); inPreview=true; } } public void surfaceDestroyed(SurfaceHolder holder) { // no-op } }; } </code></pre>
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