Android: Switch camera when button clicked

Question

I have a method called switchCamera, I'm trying to switch camera from front to back on the click of a button, in one smooth transition. My application freezes when I call this method - I know I'm not doing something right. Can anyone help me out here?

Any help is much appreciated.

public void switchCamera(){     int camNum = 0;     camNum = Camera.getNumberOfCameras();     int camBackId = Camera.CameraInfo.CAMERA_FACING_BACK;     int camFrontId = Camera.CameraInfo.CAMERA_FACING_FRONT;      Camera.CameraInfo currentCamInfo = new Camera.CameraInfo();      //if camera is running     if (camera != null){         //and there is more than one camera         if (camNum > 1){             //stop current camera             camera.stopPreview();             camera.setPreviewCallback(null);             //camera.takePicture(null, null, PictureCallback);             camera.release();             camera = null;             //stop surfaceHolder?              if (currentCamInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT){                 //switch camera to back camera                 camera=Camera.open(camBackId);             }             else{                 //switch camera to front camera                 camera=Camera.open(camFrontId);             }             //switch camera back on             //specify surface?             try {                 camera.setPreviewDisplay(surfaceHolder);                 camera.setPreviewCallback((PreviewCallback) this);                 camera.startPreview();             } catch (IOException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }         }     } } 

Answer 1

Button otherCamera = (Button) findViewById(R.id.OtherCamera);  otherCamera.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (inPreview) {     camera.stopPreview(); } //NB: if you don't release the current camera before switching, you app will crash camera.release();  //swap the id of the camera to be used if(currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK){     currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT; } else {     currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK; } camera = Camera.open(currentCameraId);  setCameraDisplayOrientation(CameraActivity.this, currentCameraId, camera); try {      camera.setPreviewDisplay(previewHolder); } catch (IOException e) {     e.printStackTrace(); } camera.startPreview(); } 

If you want to make the camera image show in the same orientation as the display, you can use the following code.

public static void setCameraDisplayOrientation(Activity activity,          int cameraId, android.hardware.Camera camera) {      android.hardware.Camera.CameraInfo info =              new android.hardware.Camera.CameraInfo();      android.hardware.Camera.getCameraInfo(cameraId, info);      int rotation = activity.getWindowManager().getDefaultDisplay()              .getRotation();      int degrees = 0;      switch (rotation) {          case Surface.ROTATION_0: degrees = 0; break;          case Surface.ROTATION_90: degrees = 90; break;          case Surface.ROTATION_180: degrees = 180; break;          case Surface.ROTATION_270: degrees = 270; break;      }       int result;      if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {          result = (info.orientation + degrees) % 360;          result = (360 - result) % 360;  // compensate the mirror      } else {  // back-facing          result = (info.orientation - degrees + 360) % 360;      }      camera.setDisplayOrientation(result);  }