放大和縮小自定義相機 - 空指針異常

我正試圖實現放大&在我的自定義相機中輸出功能。放大和縮小自定義相機 - 空指針異常

NullPointerException: zoomControls.setVisibility(View.GONE);

我使用這個：Zoom Control in Camera is not working in Android

PreviewSurface.java:-

public class PreviewSurface extends SurfaceView implements 
    SurfaceHolder.Callback { 

     public static final String LOG_TAG = "CameraPreview"; 
     private SurfaceHolder mSurfaceHolder; 
     SurfaceView mSurfaceView; 
     private Camera mCamera; 
     Camera.Parameters params ; 
     int currentZoomLevel = 0, maxZoomLevel = 0; 
     // Constructor that obtains context and camera 
     @SuppressWarnings("deprecation") 
     public PreviewSurface(Context context, Camera camera) { 
      super(context); 
      this.mCamera = camera; 
      mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView); 
      this.mSurfaceHolder = this.getHolder(); 
      this.mSurfaceHolder.addCallback(this); 
      this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
      this.mSurfaceHolder.setFixedSize(100, 100); 
     } 

     @Override 
     public void surfaceCreated(SurfaceHolder surfaceHolder) { 
      try { 
       mCamera.setPreviewDisplay(surfaceHolder); 
       mCamera.startPreview(); 
      } catch (IOException e) { 
       // left blank for now 
      } 
     } 

     @Override 
     public void surfaceDestroyed(SurfaceHolder surfaceHolder) { 
      mCamera.stopPreview(); 
      mCamera.release(); 
     } 

     @Override 
     public void surfaceChanged(SurfaceHolder surfaceHolder, int format, 
       int width, int height) { 

      ZoomControls zoomControls = (ZoomControls) findViewById(R.id.CAMERA_ZOOM_CONTROLS); 
      params = mCamera.getParameters(); 


       if (params.isZoomSupported() && params.isSmoothZoomSupported()) { 
        //most phones 
        maxZoomLevel = params.getMaxZoom(); 

        zoomControls.setIsZoomInEnabled(true); 
        zoomControls.setIsZoomOutEnabled(true); 

        zoomControls.setOnZoomInClickListener(new OnClickListener() { 
         public void onClick(View v) { 
          if (currentZoomLevel < maxZoomLevel) { 
           currentZoomLevel++; 
           mCamera.startSmoothZoom(currentZoomLevel); 

          } 
         } 
        }); 

        zoomControls.setOnZoomOutClickListener(new OnClickListener() { 
         public void onClick(View v) { 
          if (currentZoomLevel > 0) { 
           currentZoomLevel--; 
           mCamera.startSmoothZoom(currentZoomLevel); 
          } 
         } 
        }); 
       } else if (params.isZoomSupported() && !params.isSmoothZoomSupported()){ 
        //stupid HTC phones 
        maxZoomLevel = params.getMaxZoom(); 

        zoomControls.setIsZoomInEnabled(true); 
        zoomControls.setIsZoomOutEnabled(true); 

        zoomControls.setOnZoomInClickListener(new OnClickListener() { 
         public void onClick(View v) { 
          if (currentZoomLevel < maxZoomLevel) { 
           currentZoomLevel++; 
           params.setZoom(currentZoomLevel); 
           mCamera.setParameters(params); 

          } 
         } 
        }); 

        zoomControls.setOnZoomOutClickListener(new OnClickListener() { 
         public void onClick(View v) { 
          if (currentZoomLevel > 0) { 
           currentZoomLevel--; 
           params.setZoom(currentZoomLevel); 
           mCamera.setParameters(params); 
          } 
         } 
        }); 
       }else{ 
        //no zoom on phone 
        zoomControls.setVisibility(View.GONE); 
       } 

       // start preview with new settings 
       try { 
        mCamera.setDisplayOrientation(90); 
        mCamera.setPreviewDisplay(surfaceHolder); 
        mCamera.startPreview(); 
       } catch (Exception e) { 
       // intentionally left blank for a test 
      } 
     } 

    }

activity_camera.xml： -

<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="horizontal" > 

<FrameLayout 
    android:id="@+id/camera_preview" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" 
    android:layout_toLeftOf="@+id/btnView" /> 

<SurfaceView 
    android:id="@+id/surfaceView" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" /> 

<ZoomControls 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBottom="@+id/camera_preview" 
    android:layout_centerInParent="true" 
    android:id="@+id/CAMERA_ZOOM_CONTROLS" /> 

<TextView 
    android:id="@+id/title" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_marginTop="18dp" 
    android:layout_toRightOf="@+id/camera_preview" 
    android:maxLines="1" 
    android:visibility="gone" 
    android:textAppearance="?android:attr/textAppearanceSmall" /> 

<Button 
    android:id="@+id/btnSettings" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/btnView" 
    android:layout_alignParentBottom="true" 
    android:layout_marginBottom="50dp" 
    android:background="@drawable/settings" /> 

<Button 
    android:id="@+id/btnView" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentRight="true" 
    android:layout_alignParentTop="true" 
    android:layout_marginTop="50dp" 
    android:background="@drawable/gallery" /> 

<Button 
    android:id="@+id/btnCapture" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_centerVertical="true" 
    android:layout_toRightOf="@+id/camera_preview" 
    android:background="@drawable/capture" /> 

</RelativeLayout>

CameraLauncherActivity.java:-

public class CameraLauncherActivity extends Activity { 

    private Camera mCamera; 
    private PreviewSurface mCameraPreview; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_camera); 
     mCamera = getCameraInstance(); 

     mCameraPreview = new PreviewSurface(this, mCamera); 
     FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); 
     preview.addView(mCameraPreview); 
    } 

private Camera getCameraInstance() { 
     Camera camera = null; 
     Log.d(CameraLauncherActivity.LOG_TAG, "getCameraInstance()Camera:: " + camera); 
     try { 
      camera = Camera.open(0); 
      Log.d(CameraLauncherActivity.LOG_TAG, "getCameraInstance()open:: " + camera); 
     } catch (Exception e) { 
      // cannot get camera or does not exist 
     } 
     return camera; 
    } 

    PictureCallback mPicture = new PictureCallback() { 
     @Override 
     public void onPictureTaken(byte[] data, Camera camera) { 
      File pictureFile = getOutputMediaFile(); 
      camera.startPreview(); 
      if (pictureFile == null) { 
       return; 
      } 
      try { 
       FileOutputStream fos = new FileOutputStream(pictureFile); 
       fos.write(data); 
       fos.close(); 
      } catch (FileNotFoundException e) { 

      } catch (IOException e) { 
      } 
     } 
    }; 

    static File getOutputMediaFile() { 

    // folder name 
    mediaStorageDir = new File(Environment        .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "/MyImages/"); 

if (!mediaStorageDir.exists()) { 
    if (!mediaStorageDir.mkdirs()) { 
    Log.d("App", "failed to create directory");     
     } 
    } 

    /* yyyy-MM-dd'T'HH:mm:ss.SSSZ */ 
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); 

    File mediaFile; 

    // file name 
    mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg"); 

     return mediaFile; 
    }

logcat的： -

11-28 01:52:43.179: E/AndroidRuntime(2135): FATAL EXCEPTION: main 
11-28 01:52:43.179: E/AndroidRuntime(2135): java.lang.NullPointerException 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at app.pd.PreviewSurface.surfaceChanged(PreviewSurface.java:113) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.SurfaceView.updateWindow(SurfaceView.java:582) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.SurfaceView.access$000(SurfaceView.java:86) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:175) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:833) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1860) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.Choreographer.doCallbacks(Choreographer.java:562) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.Choreographer.doFrame(Choreographer.java:532) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.os.Handler.handleCallback(Handler.java:730) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.os.Handler.dispatchMessage(Handler.java:92) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.os.Looper.loop(Looper.java:137) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at android.app.ActivityThread.main(ActivityThread.java:5103) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at java.lang.reflect.Method.invokeNative(Native Method) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at java.lang.reflect.Method.invoke(Method.java:525) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
11-28 01:52:43.179: E/AndroidRuntime(2135):  at dalvik.system.NativeStart.main(Native Method)

來源

2013-11-27 Android

使用相機變焦控制[這裏] [1] [1]：http://stackoverflow.com/questions/18270222/zoom-control也許在你的構造函數，你應該有以下初始化 - 相機不工作在安卓/ 19248882＃19248882 它會爲你工作 –

@ RP-TechValens請看看這個問題 – Android

在您的代碼中，params未曾初始化，因此其值始終爲空。如果您嘗試在空對象上使用方法，將導致NullPointerException。

params = mCamera.getParameters();

來源

2013-11-28 06:32:12 Alec

是啊謝謝你的錯誤我刪除了這行代碼，不能接受你的答案，但勾選爲有用的.. – Android

現在爲什麼我在這裏得到NPE：zoomControls.setVisibility（View.GONE）;今天發生了什麼事 – Android

試試這個代碼：

@Override 
    public boolean onTouch(View v, MotionEvent event) { 
     // TODO Auto-generated method stub 

     switch (event.getAction() & MotionEvent.ACTION_MASK) { 
     case MotionEvent.ACTION_DOWN: 
      break; 
     case MotionEvent.ACTION_POINTER_DOWN: 
      break; 
     case MotionEvent.ACTION_UP: 
     case MotionEvent.ACTION_POINTER_UP: 
      mode = NONE; 
      Log.d(TAG, "mode=NONE"); 
      break; 
     case MotionEvent.ACTION_MOVE: 
      if (mode == ZOOM) { 
        float newDist = spacing(event); 

        double zoomDist = newDist-oldDist; 

        if(zoomDist > 0){ 
         if(zoomDist > 50 && zoomDist <= 200){ 

          if (curZoomLevel < mZoomMax && gestureZoom == 0) { 
           gestureZoom ++; 
           GestureZoomIn(); 
          } 

         }else if(zoomDist > 200 && zoomDist <= 300){ 


          if (curZoomLevel < mZoomMax && gestureZoom == 1) { 

           gestureZoom ++; 
           GestureZoomIn(); 
          } 
         }else if(zoomDist > 300 && zoomDist <= 400){ 

          if (curZoomLevel < mZoomMax && gestureZoom == 2) { 

           gestureZoom++; 
           GestureZoomIn(); 
          } 
      break; 
     } 

     view.setImageMatrix(matrix); 
     return true; 
    } 


private void GestureZoomIn(){ 
     if (mParameters.isZoomSupported()){ 
      mZoomMax = mParameters.getMaxZoom(); 
      if (zoom_text_value<mZoomMax) { 
       zoom_text_value++; 
       curZoomLevel++; 
       zoom_float=zoom_float+0.5; 
       onZoomValueChanged(curZoomLevel); 

private void GestureZoomOut(){ 
     if (mParameters.isZoomSupported()){ 

      if (0<zoom_text_value) { 
       zoom_text_value--; 
       curZoomLevel--; 
       zoom_float=zoom_float-0.5; 
       onZoomValueChanged(curZoomLevel);

，這可能是幫你。

來源

2013-11-27 06:39:41

我已經通過這個鏈接：http：// stackoverflow.com/questions/16482825/android-custom-camera-zoom-not-working?rq=1 – Android

所以這是不工作... –

看到我編輯的答案.. –

放大和縮小自定義相機 - 空指針異常

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