Android onActivityResult not called / triggered

Question

I read much about issues with onActivityResult, but it seems that none of the described problems fit to mine, like putting a negative requestCode in startActivityForResult or something else.

I'm playing with the camera in my Activity, which streams its preview to a SurfaceView. After taking a picture, I close the cam releasing its resources, call setResult(RESULT_OK, DataIntent) and hoping that onActivityResult is triggered in my parent.

But it doesn't. If I set a result in onCreate of the child Activity and finish the child in onCreate the result is not passed to onActivityResult.

What possible reason could it be that onActivityResult is not getting triggered? I'll write some of my source down for understanding of what I'm doing...

public class MainActivity extends Activity {     Button mButtonScan;      /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);          mButtonScan = (Button)findViewById(R.id.main_btn_scan);     }      /**     * OnClick Event called from main.xml     * @param v View that called that onClickEvent     */     public void btnCaptureClick(View v) {         Intent intent = new Intent(this, CaptureActivity.class);         startActivityForResult(intent, Constants.REQUEST_CODE_CAPTURE);     }      /**     * callback for this Activity. Called when an Activity which was started by     * this.startActivityForResult(intent, requestCode) sets its result and calls finish()     */     @Override     protected void onActivityResult(int requestCode, int resultCode, Intent data) {         String foo = "foo";         switch (requestCode) {             case Constants.REQUEST_CODE_CAPTURE:                 switch (resultCode) {                     case RESULT_FIRST_USER:                         Toast.makeText(this, data.getStringExtra(Config.SCAN_RESULT_TEXT), Toast.LENGTH_LONG).show();                         break;                     case RESULT_CANCELED:                         break;                     default:                         break;                 }                 break;              default:                 super.onActivityResult(requestCode, resultCode, data);                 break;         }     } }   public class CaptureActivity extends Activity implements ActivityCallback, SurfaceHolder.Callback, PreviewCallback {      private Preview mPreview;     private Camera mCam;     private SurfaceHolder mHolder;     private Size size;      protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.capture);          mPreview = (Preview)findViewById(R.id.capture_preview);      }      @Override     public void onValidDecodeResult(Result rawResult, Bitmap barcode) {         Intent intent = new Intent();         if (rawResult != null && barcode != null) {             intent.putExtra(Config.SCAN_RESULT_TEXT, rawResult.getText());             intent.putExtra(Config.SCAN_RESULT_FORMAT, rawResult.getBarcodeFormat().getName());             intent.putExtra(Config.SCAN_RESULT_BMP, barcode);         } else {             intent.putExtra(Config.SCAN_RESULT_TEXT, "foo");             intent.putExtra(Config.SCAN_RESULT_FORMAT, "bar");             intent.putExtra(Config.SCAN_RESULT_BMP, "barcode");         }         mPreview = null;         setResult(Activity.RESULT_FIRST_USER, intent);         finish();        }      @Override     public void onPreviewFrame(byte[] data, Camera camera) {         MultiFormatReader reader = new MultiFormatReader();              PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(data, size.width, size.height, 160, 60, 480, 360);         GlobalHistogramBinarizer binarizer = new GlobalHistogramBinarizer(source);         BinaryBitmap bb = new BinaryBitmap(binarizer);         Result result = null;         try {             result = reader.decode(bb);         } catch (NotFoundException e) {             //do NOTHING cause e == null         } catch (Exception e){             e.printStackTrace();         } finally {             reader.reset();         }         if (result != null) {             mCam.stopPreview();             releaseCameraResources();             onValidDecodeResult(result, source.renderCroppedGreyscaleBitmap());         } else {             camera.setOneShotPreviewCallback(this);         }            }      @Override     public void surfaceCreated(SurfaceHolder holder) {         try {             mCam = Camera.open();             mCam.setPreviewDisplay(mPreview.getHolder());         } catch (IOException e) {             releaseCameraResources();             e.printStackTrace();         }                }      private void releaseCameraResources() {         mCam.release();         mCam = null;     }      @Override     public void surfaceChanged(SurfaceHolder holder, int format, int width,         int height) {         //begin Preview         Camera.Parameters parameters = mCam.getParameters();          List<Size> sizes = parameters.getSupportedPreviewSizes();          size = getOptimalPreviewSize(sizes, width, height);         parameters.setPreviewSize(size.width, size.height);          mCam.setParameters(parameters);         mCam.startPreview();         mCam.setOneShotPreviewCallback(this);     }      @Override     public void surfaceDestroyed(SurfaceHolder holder) {         if (mCam != null) {             mCam.stopPreview();             releaseCameraResources();         }        }      private Size getOptimalPreviewSize(List<Size> sizes, int width, int height) {         final double ASPECT_TOLERANCE = 0.05;         double targetRatio = (double) width / height;          if (sizes == null) return null;              Size optimalSize = null;             double minDiff = Double.MAX_VALUE;              int targetHeight = height;              for (Size size: sizes) {                 double ratio = (double) size.width / size.height;                 if(Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) {                     continue;                 }                  if (Math.abs(size.height - targetHeight) < minDiff) {                     optimalSize = size;                     minDiff = Math.abs(size.height - targetHeight);                 }                            }              if (optimalSize == null) {                 //cannot find matching aspect-ratio                 minDiff = Double.MAX_VALUE;                 for (Size size : sizes) {                     if (Math.abs(size.height - targetHeight) < minDiff) {                         optimalSize = size;                         minDiff = Math.abs(size.height - targetHeight);                 }             }         }         return optimalSize;     } } 

Answer 1

Make sure the number parameter (requestCode) passed to startActivityForResult(...) is >=0

Answer 2

Had the same problem. check your manifest and make sure you are NOT using single instance:

android:launchMode="singleInstance"