android - SurfaceView 相机预览代码在 Pre Lollipop 上运行良好但在 Lollipop 设备上崩溃

Question

我实现了一个自定义的 SurfaceView 来绘制相机预览，并在其上完成了所有捕获和手动对焦操作。它在 Pre-Lolipop 设备上运行良好，但问题是它在 Lollipop 设备上崩溃。 发生的最奇怪的事情是，应用程序抛出 ANR，当我单击“确定”时，应用程序从我离开它的地方开始运行。
LogCat 显示“在跳过 ANR 后无法连接到相机错误，我可以轻松连接甚至操纵我的相机”。是因为我使用了已弃用的 Camera API 而不是 Camera2 和 Lollipop 设备吗？？

我的代码是这样的:

public class CameraPreview
implements
SurfaceHolder.Callback {
private int cameratype=Camera.CameraInfo.CAMERA_FACING_BACK;
private Camera mCamera = null;
public Camera.Parameters params;
private SurfaceHolder sHolder;
private String TAG="CameraPreview";
public List<Camera.Size> supportedSizes;

public int isCamOpen = 0;
public boolean isSizeSupported = false;
private int previewWidth, previewHeight;
private List<String> mSupportedFlashModes;
private boolean flashon=false;
private final static String MYTAG = "CameraPreview";
private ProgressDialog loading;

public CameraPreview(int width, int height) {
    Log.i("campreview", "Width = " + String.valueOf(width));
    Log.i("campreview", "Height = " + String.valueOf(height));
    previewWidth = width;
    previewHeight = height;
}

private int openCamera() {
    if (isCamOpen == 1) {
        releaseCamera();
    }

    mCamera = Camera.open(cameratype);

    if (mCamera == null) {
        return -1;
    }

    if (TouchActivity.reference.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
        mCamera.setDisplayOrientation(90);
    } else {
        mCamera.setDisplayOrientation(0);
    }

    params = mCamera.getParameters();
    params.setPreviewSize(previewWidth, previewHeight);

    try {
        mCamera.setParameters(params);
    } catch (RuntimeException e) {
        e.printStackTrace();
    }

    mCamera.startPreview();
    try {
        mCamera.setPreviewDisplay(sHolder);
    } catch (IOException e) {
        mCamera.release();
        mCamera = null;
        return -1;
    }
    isCamOpen = 1;
    return isCamOpen;
}
public int isCamOpen() {
    return isCamOpen;
}

public void releaseCamera() {
    if (mCamera != null) {
        mCamera.stopPreview();
        mCamera.setPreviewCallback(null);
        mCamera.release();
        mCamera = null;
    }
    isCamOpen = 0;
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    sHolder = holder;
    isCamOpen = openCamera();
}

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

}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {

    releaseCamera();

}

/**
 * Called from PreviewSurfaceView to set touch focus.
 * 
 * @param - Rect - new area for auto focus
 */
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public void doTouchFocus(final Rect tfocusRect) {
    Log.i(TAG, "TouchFocus");
    try {
        final List<Camera.Area> focusList = new ArrayList<Camera.Area>();
        Camera.Area focusArea = new Camera.Area(tfocusRect, 1000);
        focusList.add(focusArea);

        Camera.Parameters para = mCamera.getParameters();
        para.setFocusAreas(focusList);
        para.setMeteringAreas(focusList);
        mCamera.setParameters(para);

        mCamera.autoFocus(myAutoFocusCallback);
    } catch (Exception e) {
        e.printStackTrace();
        Log.i(TAG, "Unable to autofocus");
    }

}

/**
 * AutoFocus callback
 */
AutoFocusCallback myAutoFocusCallback = new AutoFocusCallback(){

      @Override
      public void onAutoFocus(boolean arg0, Camera arg1) {
       if (arg0){
        mCamera.cancelAutoFocus();      
       }
    }
};




public void capturePicture(){
    mCamera.takePicture(null, null, mPicture);


}

private File getOutputMediaFile(){

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "UltimateCameraGuideApp");

    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            Log.d("Camera Guide", "Required media storage does not exist");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    mediaFile = new File(mediaStorageDir.getPath() + File.separator +
            "IMG_"+ timeStamp + ".jpg");

    //DialogHelper.showDialog("Success!", "Your picture has been saved!", TouchActivity.reference.getActivity());

    return mediaFile;
}

private Camera.PictureCallback mPicture = new Camera.PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        //This One is Just for Getting a File Named after it
         loading=new ProgressDialog(BaseImagesContainer.reference);
        loading.setMessage("Getting Image Ready");
        loading.show();
        File pictureFile =getOutputMediaFile();
        if (pictureFile == null){
            Toast.makeText(TouchActivity.reference.getActivity(), "Image retrieval failed.", Toast.LENGTH_SHORT)
                    .show();
            return;
        }
        Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
        if(cameratype==Camera.CameraInfo.CAMERA_FACING_BACK){
            bmp=rotateImage(90,bmp);
        }else{
            bmp=rotateImage(270,bmp);

        }
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bmp.compress(Bitmap.CompressFormat.PNG,1, stream);
        byte[] flippedImageByteArray = stream.toByteArray();
        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(flippedImageByteArray);
            fos.close();
            // Restart the camera preview.
            //safeCameraOpenInView(mCameraView);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        Uri destination = Uri.fromFile(new File(TouchActivity.reference.getActivity().getCacheDir(), "cropped"));
        Uri source = Uri.fromFile(new File(pictureFile.getPath()));
        Crop.of(source, destination).withMaxSize(800,800).start(TouchActivity.reference.getActivity());
    }
};


public Bitmap rotateImage(int angle, Bitmap bitmapSrc) {
    Matrix matrix = new Matrix();
    matrix.postRotate(angle);
    return Bitmap.createBitmap(bitmapSrc, 0, 0,
            bitmapSrc.getWidth(), bitmapSrc.getHeight(), matrix, true);
}


public void switchCamera(){

    mCamera.stopPreview();
    //NB: if you don't release the current camera before switching, you app will crash
    mCamera.release();

    //swap the id of the camera to be used
    if(cameratype==Camera.CameraInfo.CAMERA_FACING_BACK){
        cameratype=Camera.CameraInfo.CAMERA_FACING_FRONT;
    }else{
        cameratype=Camera.CameraInfo.CAMERA_FACING_BACK;
    }
    try{
        mCamera = Camera.open(cameratype);
    }catch (Exception e){
        e.printStackTrace();
        Toast.makeText(TouchActivity.reference.getActivity(),"Can't Open the Camera",Toast.LENGTH_LONG).show();
    }

    if (TouchActivity.reference.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {

        mCamera.setDisplayOrientation(90);

    } else {

        mCamera.setDisplayOrientation(0);

    }

    try{
        mCamera.setPreviewDisplay(sHolder);
        mCamera.startPreview();
    }
    catch(Exception e){
        e.printStackTrace();
    }

}

public void switchflash(){
    //Do the On Flash for now
    if(!flashon){
        mSupportedFlashModes = mCamera.getParameters().getSupportedFlashModes();
        if (mSupportedFlashModes != null && mSupportedFlashModes.contains(Camera.Parameters.FLASH_MODE_AUTO)){
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
            mCamera.setParameters(parameters);
        }
    }else{
        //flash on
        //do teh off now
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
        mCamera.setParameters(parameters);
    }
    flashon=!flashon;

}

public void stopLoading(){
    loading.dismiss();
    //DialogHelper.showDialog("Oops!", "Your crop had been cancelled !", TouchActivity.reference.getActivity());

}

Answer 1

根本原因与 Camera Preview appearing really slow in Android 中的相同。我什至在我的 comment 中提到过 ANR那里。

为避免 ANR，您必须将 Camera.open() 卸载到另一个线程。如果您投资在处理程序线程上执行此操作，如所述here ，您的 onPictureTaken() 回调也不会导致 ANR。

您需要将此回调的某些部分包装在 runOnUiThread() 中，但这肯定会有所返回。