Android「不幸已停止」錯誤

我是新來的android編程。我只想在android中製作自定義相機。爲了做到這一點，我用這個網站（http://developer.android.com/guide/topics/media/camera.html）雖然我遵循網站的步驟，但我收到了一個錯誤，「不幸的是，您的應用程序已停止」。我搜索了關於「不幸已經停止」的所有問題，並且我在這裏閱讀了答案。但他們沒有幫助我。請幫幫我！Android「不幸已停止」錯誤

這裏是我的cameraActivity代碼：

public class CameraActivity extends Activity { 

protected static final String TAG = null; 
protected static final String MEDIA_TYPE_IMAGE = ".jpeg"; 
private static Camera mCamera; 
private CameraPreview mPreview; 

@Override 
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); 
    preview.addView(mPreview); 


    final PictureCallback mPicture = new PictureCallback() { 

     @Override 
     public void onPictureTaken(byte[] data, Camera camera) { 

      File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE); 
      if (pictureFile == null){ 
       Throwable e = null; 
       Log.d(TAG, "Error creating media file, check storage permissions: " + 
        e.getMessage()); 
       return; 
      } 

      try { 
       FileOutputStream fos = new FileOutputStream(pictureFile); 
       fos.write(data); 
       fos.close(); 
      } catch (FileNotFoundException e) { 
       Log.d(TAG, "File not found: " + e.getMessage()); 
      } catch (IOException e) { 
       Log.d(TAG, "Error accessing file: " + e.getMessage()); 
      } 
     } 

     private File getOutputMediaFile(String mediaTypeImage) { 
      // TODO Auto-generated method stub 
      return null; 
     } 
    }; 

Button captureButton = (Button) findViewById(id.button_capture); 
captureButton.setOnClickListener(
    new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // get an image from the camera 
      mCamera.takePicture(null, null, mPicture); 
     }});} 

public static Camera getCameraInstance(){ 
    Camera c = null; 
    try { 
     c = Camera.open(); // attempt to get a Camera instance 
    } 
    catch (Exception e){ 
     // Camera is not available (in use or does not exist) 
    } 
    return c; // returns null if camera is unavailable 
}}

，當我在logcat中點擊錯誤，這表明我這個

"mcamera.setPreviewDisplay(holder);"

在此代碼：

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) { 
    // 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()); 
    } 
}

在logcat的

E/AndroidRuntime(1071): FATAL EXCEPTION: main 
E/AndroidRuntime(1071): java.lang.NullPointerException 
E/AndroidRuntime(1071): at com.example.ntry.CameraPreview.surfaceCreated(CameraPreview.java:32) 
E/AndroidRuntime(1071): at android.view.SurfaceView.updateWindow(SurfaceView.java:569) 
E/AndroidRuntime(1071): at android.view.SurfaceView.access$000(SurfaceView.java:86) 
E/AndroidRuntime(1071): at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:174) 
E/AndroidRuntime(1071): at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:680) 
E/AndroidRuntime(1071): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1842) 
E/AndroidRuntime(1071): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989) 
E/AndroidRuntime(1071): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351) 
E/AndroidRuntime(1071): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 
E/AndroidRuntime(1071): at android.view.Choreographer.doCallbacks(Choreographer.java:562) 
E/AndroidRuntime(1071): at android.view.Choreographer.doFrame(Choreographer.java:532) 
E/AndroidRuntime(1071): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 
E/AndroidRuntime(1071): at android.os.Handler.handleCallback(Handler.java:725) 
E/AndroidRuntime(1071): at android.os.Handler.dispatchMessage(Handler.java:92) 
E/AndroidRuntime(1071): at android.os.Looper.loop(Looper.java:137) 
E/AndroidRuntime(1071): at android.app.ActivityThread.main(ActivityThread.java:5041) 
E/AndroidRuntime(1071): at java.lang.reflect.Method.invokeNative(Native Method) 
E/AndroidRuntime(1071): at java.lang.reflect.Method.invoke(Method.java:511) 
E/AndroidRuntime(1071): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
E/AndroidRuntime(1071): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
E/AndroidRuntime(1071): at dalvik.system.NativeStart.main(Native Method)

來源

2013-07-04 Adaichi

什麼是在線32 CameraPreview？ – Raghunandan

@Raghunandan第32行 - >「mcamera.setPreviewDisplay（holder）;」 – Adaichi

如果你想要好的攝像頭代碼示例看看這個項目由大學生完成https://github.com/ProjPossibility/2014-CSUN-Cam4Blind – portfoliobuilder

如果它在您的應用程序啓動時發生第一次那麼你的相機對象是空的或你的持有者是空的

但是，如果它發生時，你第二次導航到你的相機視圖，那麼你的相機保留與前一個視圖，第二次不可訪問，那麼你必須鬆開相機上暫停您的視圖或破壞你的觀點

希望這將有助於

來源

2013-07-04 07:50:59 farrukh

我不明白。你的意思是在Camera c = null中有問題？ – Adaichi

你從第一次應用rns就會發生這種崩潰嗎？ – farrukh

是的，我第一次運行應用程序時崩潰了。 – Adaichi

從這裏看起來getCameraInstance被返回null。 Camera.open()是否引發異常？

來源

2013-07-04 07:55:05 SK9

不，沒有關於Camera.open（）的例外。 – Adaichi

你的'mcamera'看起來是空的，這是查看你的代碼的一種方式。另一個是'.open（）'在不引發NPE的情況下返回null。 – SK9

我該如何解決這些問題？ – Adaichi

Android「不幸已停止」錯誤

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