Question

如果我在 surfaceDestroyed（....） <中未使用 mCamera.release（）; / strong>然后 无法再次从其他活动启动CameraActivity [简而言之遗憾的应用已停止]错误， 甚至不发布相机 ，但如果我点击主页按钮 [来自CameraActivity ]，然后再点击 启动我的应用 ，没有收到任何错误（简而言之，并且没有任何问题地打开CameraActivity）

如果我使用 * mCamera.release（）; *在 surfaceDestroyed（。 ...） 然后 能够再次从其他活动 启动CameraActivity， 再次发布相机 ，但是 当我点击“主页”按钮，然后再次启动我的应用时，感到很遗憾应用已停止 ....：
< / LI>
但我希望两件事情协同工作（首先， 从CameraActivity点击主页，再次从CameraActivity启动应用 - 没有任何错误）和（第二， 从其他活动中启动相机 - 没有任何错误）

就像我写的那样，这两件事都适合我，但不是在一起......

第33行是：

Camera.Parameters parameters = mCamera.getParameters();

完成日志：

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 } } }

Answer 1

试试这个，用我的代码替换你的代码，我想这会对你有所帮助， 我没试过，但看起来会解决你的错误

      @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {     

        this.getHolder().removeCallback(this);
        mCamera.stopPreview();
        mCamera.release();
    }

尽快告诉我......

Answer 2

很高兴，因为当您按下主页按钮时，您当前的活动将处于onStop模式＆amp;当你再次回来时，它将从onRestart状态开始。不是来自PreviewSurface的构造函数，您可以在其中获取相机的保持力。所以，在没有人试图抓住同一台相机之前，没有人会这么做。

但是当你从另一个Activity开始呈现使用SurfaceView的Activity时，它将从构造函数＆amp;将尝试抓住您之前的活动已经拥有的相同相机。

Answer 3

我认为您的相机为空，看起来您忘了初始化相机

 mCamera = Camera.open();

Answer 4

看看这个和

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
    }
}

Answer 5

不是覆盖onPause（）和onResume（），而是覆盖onStop（）和onRestart（）。在活动生命周期中，当活动不可见时调用onStop（），下一个生命周期方法调用将调用onRestart（）。看看下面的代码。

@Override
    protected void onStop() {
        super.onStop();
        try {
            m_camera.stopPreview();
            m_camera.release();
            preview.removeView(m_CameraPreview);

            }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

m_CameraPreview是类的对象，如下所示：公共类CameraSurfaceView扩展了SurfaceView实现的Callback

以下是onRestart方法：

    @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. 
*/
    }

框架布局将保留前一个相机实例及其相关实例。除了新的相机对象之外，还将创建surfaceview回调，从而创建竞争条件。因此，您需要在onStop（）中释放它并在onRestart（）中重新初始化。希望这会有所帮助。

Answer 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);
    }

java.lang.RuntimeException：release（）之后调用的方法

6 个答案: