CameraPreview не работает: ошибка при загрузке камеры

Question

мое приложение должно содержать полноэкранную камеру. Я не знаю, где моя ошибка, приложение быстро закрывается после запуска.

Это мой код:

Основная деятельность

public class MainActivity extends AppCompatActivity{ 

    private static final String LOG = "MainActivity.java"; 

    private Camera mCamera; 
    private CameraPreview mPreview; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    FloatingActionButton fabPref = (FloatingActionButton)  findViewById(R.id.fabPref); 
    fabPref.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

     } 
    }); 

    FloatingActionButton fabPhoto = (FloatingActionButton) findViewById(R.id.fabPhoto); 
    fabPhoto.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

     } 
    }); 

    FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); 


    if(checkCameraHardware(this)==true){ 
     Log.e("CAMERA", "vorhanden"); 


     // 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); 
     preview.addView(mPreview); 

    }else{ 
     Log.e("CAMERA", "nicht vorhanden"); 
    } 

    } 
    private boolean checkCameraHardware(Context context) { 
    if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) { 
     return true; 
    } else { 
     return false; 
    } 
    } 

public Camera getCameraInstance(){ 
    Camera c = null; 
    try { 
     releaseCameraAndPreview(); 
     c = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK); // attempt to get a Camera instance 
     Log.e(LOG, "CameraInstance: " + c + " RUNS"); 
    } 
    catch (Exception e){ 
     Log.e(LOG, "Camera not available"); 
     Log.e(LOG, "CameraInstance: " + c); 
    } 
    Log.e(LOG, "CameraInstance: " + c); 

    return c; // returns null if camera is unavailable 

} 

private void releaseCameraAndPreview() { 
    if (mCamera != null) { 
     mCamera.stopPreview(); 
     mCamera.release(); 
     mCamera = null; 
    } 
} 
    } 

Это код моего CameraPreview:

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { 

private static final String TAG = "CameraPreview.java"; 

private SurfaceHolder mHolder; 
private Camera mCamera; 

public CameraPreview(Context context, Camera camera) { 
    super(context); 
    mCamera = camera; 

    // Install a SurfaceHolder.Callback so we get notified when the 
    // underlying surface is created and destroyed. 
    mHolder = getHolder(); 
    mHolder.addCallback(this); 
    // deprecated setting, but required on Android versions prior to 3.0 
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
} 

public void surfaceCreated(SurfaceHolder holder) { 
    // The Surface has been created, now tell the camera where to draw the preview. 
    try { 
     mCamera.setPreviewDisplay(holder); 
     mCamera.startPreview(); 
    } catch (IOException e) { 
     Log.d(TAG, "Error setting camera preview: " + e.getMessage()); 
    } 
} 

public void surfaceDestroyed(SurfaceHolder holder) { 
    // empty. Take care of releasing the Camera preview in your activity. 
} 

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
    // If your preview can change or rotate, take care of those events here. 
    // Make sure to stop the preview before resizing or reformatting it. 

    if (mHolder.getSurface() == null){ 
     // preview surface does not exist 
     return; 
    } 

    // stop preview before making changes 
    try { 
     mCamera.stopPreview(); 
    } catch (Exception e){ 
     // ignore: tried to stop a non-existent preview 
    } 

    // set preview size and make any resize, rotate or 
    // reformatting changes here 

    // start preview with new settings 
    try { 
     mCamera.setPreviewDisplay(mHolder); 
     mCamera.startPreview(); 

    } catch (Exception e){ 
     Log.d(TAG, "Error starting camera preview: " + e.getMessage()); 
    } 
} 
} 

И это мой LogCat после запуска Приложение:

2-16 19:54:06.621 13572-13572/de.aintlarry.shotanalysis I/art: Late-enabling -Xcheck:jni 
12-16 19:54:06.622 13572-13572/de.aintlarry.shotanalysis I/art: VMHOOK: rlim_cur : 0 pid:13572 
12-16 19:54:06.717 13572-13572/de.aintlarry.shotanalysis W/System: ClassLoader referenced unknown path: /data/app/de.aintlarry.shotanalysis-2/lib/arm64 
12-16 19:54:06.834 13572-13572/de.aintlarry.shotanalysis E/CAMERA: vorhanden 
12-16 19:54:06.847 13572-13572/de.aintlarry.shotanalysis W/CameraBase: An error occurred while connecting to camera: 0 
12-16 19:54:07.149 13572-13572/de.aintlarry.shotanalysis W/CameraBase: An error occurred while connecting to camera: 0 
12-16 19:54:07.450 13572-13572/de.aintlarry.shotanalysis W/CameraBase: An error occurred while connecting to camera: 0 
12-16 19:54:07.751 13572-13572/de.aintlarry.shotanalysis W/CameraBase: An error occurred while connecting to camera: 0 
12-16 19:54:08.052 13572-13572/de.aintlarry.shotanalysis W/CameraBase: An error occurred while connecting to camera: 0 
12-16 19:54:08.352 13572-13572/de.aintlarry.shotanalysis I/Camera2Mode: fail 
12-16 19:54:08.352 13572-13572/de.aintlarry.shotanalysis E/MainActivity.java: Camera not available 
12-16 19:54:08.352 13572-13572/de.aintlarry.shotanalysis E/MainActivity.java: CameraInstance: null 
12-16 19:54:08.352 13572-13572/de.aintlarry.shotanalysis E/MainActivity.java: CameraInstance: null 
12-16 19:54:08.430 13572-13621/de.aintlarry.shotanalysis I/Adreno: QUALCOMM build : 8e7809e, Ic2ca81afa7 
Build Date : 09/18/15 
OpenGL ES Shader Compiler Version: XE031.05.13.02 
Local Branch : 
Remote Branch : refs/tags/AU_LINUX_ANDROID_PRIVATE_REDFOX64_MBR_RB1.05.01.01.003.020 
Remote Branch : NONE 
Reconstruct Branch : NOTHING 
12-16 19:54:08.481 13572-13572/de.aintlarry.shotanalysis E/AndroidRuntime: FATAL EXCEPTION: main 
Process: de.aintlarry.shotanalysis, PID: 13572 
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.hardware.Camera.setPreviewDisplay(android.view.SurfaceHolder)' on a null object reference 
at de.aintlarry.shotanalysis.CameraPreview.surfaceCreated(CameraPreview.java:33) 
at android.view.SurfaceView.updateWindow(SurfaceView.java:582) 
at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:177) 
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944) 
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2140) 
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1162) 
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6229) 
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:873) 
at android.view.Choreographer.doCallbacks(Choreographer.java:676) 
at android.view.Choreographer.doFrame(Choreographer.java:606) 
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:859) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:168) 
at android.app.ActivityThread.main(ActivityThread.java:5781) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:687) 
12-16 19:54:10.562 13572-13572/de.aintlarry.shotanalysis D/Process: killProcess, pid=13572 
12-16 19:54:10.571 13572-13572/de.aintlarry.shotanalysis D/Process: com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException:113 java.lang.ThreadGroup.uncaughtException:693 java.lang.ThreadGroup.uncaughtException:69 

Кто-нибудь знает проблему? Я пробовал все предложения, которые я нашел.

Answer 1

Пожалуйста, измените этот

public void surfaceCreated(SurfaceHolder holder) { 
    // The Surface has been created, now tell the camera where to draw the preview. 
    try { 
     mCamera.setPreviewDisplay(holder); 
     mCamera.startPreview(); 
    } catch (IOException e) { //This catch block does not handle NullPointers 
     Log.d(TAG, "Error setting camera preview: " + e.getMessage()); 
    } 
} 

этому

public void surfaceCreated(SurfaceHolder holder) { 
    // The Surface has been created, now tell the camera where to draw the preview. 
    try { 
     mCamera.setPreviewDisplay(holder); 
     mCamera.startPreview(); 
    } catch (Exception e) { //This catch block does handle NullPointers 
     Log.d(TAG, "Error setting camera preview: " + e.getMessage()); 
    } 
} 

catch блок вы использовали слишком узким и не поймать mCamera объект является нулевым. Это предотвратит крах, но вы также должны проверить, почему mCamera имеет значение NULL, и если он может/должен быть. Однако вполне возможно, что он просто еще не инициализирован и будет в будущем звонить :-)