java.lang.RuntimeException: Method called after release()

问题:

1. If i am not using mCamera.release(); in surfaceDestroyed(....) then not able to launch CameraActivity again from another Activity [in short getting Unfortunately app has stopped] error, even not releasing Camera, but if i do tap on Home button [from CameraActivity], and then again launching my app, not getting any error (in short works fine, and opening CameraActivity without any problem)

2. And if i am using *mCamera.release();* in surfaceDestroyed(....) then able to launch CameraActivity again from another Activity and releasing Camera as well, but when i do tap on Home button, and then again launching my app, getting Unfortunately app has stopped....:

But i want both things working together (first, Tap on Home from CameraActivity, and again launch app from CameraActivity - without any error) and (second, launching camera from another activity - without any error)

Like i wrote, both the things are working for me, but not together.....

Line number 33 is:

        Camera.Parameters parameters = mCamera.getParameters(); 

complete Log:

12-30 12:18:58.070: W/dalvikvm(14822): threadid=1: thread exiting with uncaught exception (group=0x41ef72a0) 12-30 12:18:58.080: E/AndroidRuntime(14822): FATAL EXCEPTION: main 12-30 12:18:58.080: E/AndroidRuntime(14822): java.lang.RuntimeException: Method called after release() 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.hardware.Camera.native_getParameters(Native Method) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.hardware.Camera.getParameters(Camera.java:1487) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at app.micheal.camr.PreviewSurface.surfaceCreated(PreviewSurface.java:33) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.SurfaceView.updateWindow(SurfaceView.java:609) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:235) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.View.dispatchWindowVisibilityChanged(View.java:7686) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1047) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1047) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1047) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1047) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1047) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1339) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1114) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4520) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.Choreographer.doCallbacks(Choreographer.java:555) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.Choreographer.doFrame(Choreographer.java:525) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.os.Handler.handleCallback(Handler.java:615) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.os.Handler.dispatchMessage(Handler.java:92) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.os.Looper.loop(Looper.java:137) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at android.app.ActivityThread.main(ActivityThread.java:4921) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at java.lang.reflect.Method.invokeNative(Native Method) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at java.lang.reflect.Method.invoke(Method.java:511) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1036) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:803) 12-30 12:18:58.080: E/AndroidRuntime(14822):    at dalvik.system.NativeStart.main(Native Method) 12-30 12:19:08.095: I/Process(14822): Sending signal. PID: 14822 SIG: 9 

PreviewSurface.java:

public class PreviewSurface extends SurfaceView implements SurfaceHolder.Callback {      public static final String LOG_TAG = "CameraPreview";     private SurfaceHolder mSurfaceHolder;      private Camera mCamera;     Camera.Parameters parameters = null ;      // Constructor that obtains context and camera     @SuppressWarnings("deprecation")     public PreviewSurface(Context context, Camera camera) {         super(context);         this.mCamera = camera;                   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 {                        parameters = mCamera.getParameters();                  if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE)                  {                      parameters.set("orientation", "portrait");                      mCamera.setDisplayOrientation(90);                      parameters.setRotation(90);                      mCamera.setPreviewDisplay(surfaceHolder);                      mCamera.startPreview();                 }                 else                  {                      // This is an undocumented although widely known feature                      parameters.set("orientation", "landscape");                      // For Android 2.2 and above                      mCamera.setDisplayOrientation(0);                      // Uncomment for Android 2.0 and above                      parameters.setRotation(0);                 }                  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) {          try {                    parameters = mCamera.getParameters();             if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {                  parameters.set("orientation", "portrait");                  mCamera.setDisplayOrientation(90);                  parameters.setRotation(90);              }                  else {                       // This is an undocumented although widely known feature                       parameters.set("orientation", "landscape");                       // For Android 2.2 and above                       mCamera.setDisplayOrientation(0);                       // Uncomment for Android 2.0 and above                       parameters.setRotation(0);             }             mCamera.setPreviewDisplay(surfaceHolder);             mCamera.startPreview();           } catch (IOException e) {             // left blank for now         }                }  } 

回答1:

try this, replace your code with mine, i guess this will help you, i have not tried but looks it will resolve your errors

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

Let me know ASAP...

回答2:

It was happning because when you press the Home button, your present Activity will be in onStop mode & when you will come back again it will start from onRestart state. Not from the constructor of PreviewSurface where you are acquiering a hold on the Camera. So, before relese nobody is trying to get a hold on the same Camera.

But when you start another Activity from you present Activity which is using a SurfaceView, that will start from the constructor & will try to get a hold on the same Camera which is already held by your previous Activity.

回答3:

i think your mCamera is null,looks like you forgot to intialize camera

 mCamera = Camera.open(); 

回答4:

look at this ans

public void surfaceCreated(SurfaceHolder surfaceHolder) {     try {             // here you should set  open camera .          mCamera= Camera.open();          Camera.Parameters parameters = mCamera.getParameters();          if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE)          {              parameters.set("orientation", "portrait");              mCamera.setDisplayOrientation(90);              parameters.setRotation(90);              mCamera.setPreviewDisplay(surfaceHolder);              mCamera.startPreview();         }         else          {              // This is an undocumented although widely known feature              parameters.set("orientation", "landscape");              // For Android 2.2 and above              mCamera.setDisplayOrientation(0);              // Uncomment for Android 2.0 and above              parameters.setRotation(0);         }         mCamera.setPreviewDisplay(surfaceHolder);         mCamera.startPreview();      } catch (IOException e) {         // left blank for now     } } 

回答5:

Instead of overriding onPause() and onResume(), override the onStop() and onRestart(). In the activity lifecycle, onStop() is called when the activity is not Visible and the next lifecycle method call would be to the onRestart(). Have a look at the code below.

@Override     protected void onStop() {         super.onStop();         try {             m_camera.stopPreview();             m_camera.release();             preview.removeView(m_CameraPreview);              }         catch(Exception e)         {             e.printStackTrace();         }     } 

m_CameraPreview is the object of the class that looks like this: public class CameraSurfaceView extends SurfaceView implements Callback

Following is the onRestart method:

    @Override     protected void onRestart() {         super.onRestart();         m_camera=getCameraInstance();//Initialize the camera in your own way         m_CameraPreview = new CameraSurfaceView(this, m_camera);        preview = (FrameLayout)findViewById(R.id.camera_preview);            preview.addView(this.m_CameraPreview); /*  *camera_preview is the id of the framelayout defined in xml file and preview is *the instance of FrameLayout.  */     } 

The frame layout will have a hold to the previous camera instance and its' surfaceview callbacks will be created in addition to the new camera object, creating a race condition. Hence you would need to release it in onStop() and reinitialize in onRestart(). Hope this helps.

回答6:

in OnPause stop the camera preview and release the camera @Override     public void onPause() {         super.onPause();         camera.stopPreview();         camera.release();         camera = null;     }  in onResume initialize the camera  @Override     public void onResume() {         super.onResume();         camera = Camera.open();         surfaceView = (SurfaceView)view.findViewById(R.id.surfaceView);         surfaceView.getHolder().addCallback(this);         surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_NORMAL);     } 

文章来源: java.lang.RuntimeException: Method called after release()