Question

我已获得此代码（基于http://developer.android.com/training/camera/cameradirect.html），但Google Glass不适合我。

代码：

public class MainActivity extends Activity {

    private Camera mCamera;
    private CameraPreview mPreview;
    private GestureDetector mGestureDetector;
    private Camera.PictureCallback mPicture;

    public static final int MEDIA_TYPE_IMAGE = 1;
    public static final int MEDIA_TYPE_VIDEO = 2;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mGestureDetector = createGestureDetector(this);

        mPicture = new Camera.PictureCallback() {

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

                File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
                if (pictureFile == null){
//                    Log.d("Camera", "Error creating media file, check storage permissions: " + e.getMessage());
                    return;

                }

                try {
                    FileOutputStream fos = new FileOutputStream(pictureFile);
                    fos.write(data);
                    fos.close();
                } catch (FileNotFoundException e) {
                    Log.d("Camera", "File not found: " + e.getMessage());
                } catch (IOException e) {
                    Log.d("Camera", "Error accessing file: " + e.getMessage());
                }
            }
        };

        // Create an instance of Camera
        mCamera = getCameraInstance();

        // Create our Preview view and set it as the content of our activity.
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);
    }


    private static File getOutputMediaFile(int type){
        // To be safe, you should check that the SDCard is mounted
        // using Environment.getExternalStorageState() before doing this.

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES), "MyCameraApp");
        // This location works best if you want the created images to be shared
        // between applications and persist after your app has been uninstalled.

        // Create the storage directory if it does not exist
        if (! mediaStorageDir.exists()){
            if (! mediaStorageDir.mkdirs()){
                Log.d("MyCameraApp", "failed to create directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        if (type == MEDIA_TYPE_IMAGE){
            mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                    "IMG_"+ timeStamp + ".jpg");
        } else if(type == MEDIA_TYPE_VIDEO) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                    "VID_"+ timeStamp + ".mp4");
        } else {
            return null;
        }

        return mediaFile;
    }
}

此行返回nullPointerException：

preview.addView(mPreview);

getCameraInstance方法：

public static Camera getCameraInstance(){
        Camera c = null;
        try {
            c = Camera.open(); // attempt to get a Camera instance
        }
        catch (Exception e){
            System.out.println(e.getMessage());
            // Camera is not available (in use or does not exist)
        }
        return c; // returns null if camera is unavailable
    }

我假装拍照没有＆＃34; TAP＆＃34;手势......有什么建议吗？

我已阅读其他帖子，但我还没有找到任何解决方案:(

提前致谢！

已更新

空指针已经解决，但现在，应用程序返回了我的错误：＆＃34;无法连接到相机服务＆＃34;

Answer 1

问题：

由于您使用的是Android相机API（http://developer.android.com/training/camera/cameradirect.html）与特定于Google眼镜的相机API（https://developers.google.com/glass/develop/gdk/camera），因此您很可能需要重新启动Google Glass。

请参阅其他问题：java.lang.RuntimeException: Fail to Connect to camera service

我多次遇到过这个问题。基本上，当您尝试连接相机并且没有正确关闭相机服务时，您将无法再次连接到它。我使用Android API和OpenCV的API遇到了这个问题。

请在>重启设备后按照下面的示例进行操作。

实施例

<强> MainActivity：

public class MainActivity extends Activity { private CameraSurfaceView cameraView; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Initiate CameraView cameraView = new CameraSurfaceView(this); // Set the view this.setContentView(cameraView); } @Override protected void onResume() { super.onResume(); // Do not hold the camera during onResume if (cameraView != null) { cameraView.releaseCamera(); } } @Override protected void onPause() { super.onPause(); // Do not hold the camera during onPause if (cameraView != null) { cameraView.releaseCamera(); } } }

<强> CameraSurfaceView：

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback { private Camera camera; @SuppressWarnings("deprecation") public CameraSurfaceView(Context context) { super(context); final SurfaceHolder surfaceHolder = this.getHolder(); surfaceHolder.addCallback(this); surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } @Override public void surfaceCreated(SurfaceHolder holder) { camera = Camera.open(); // Show the Camera display try { camera.setPreviewDisplay(holder); } catch (IOException e) { this.releaseCamera(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // Start the preview for surfaceChanged if (camera != null) { camera.startPreview(); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { // Do not hold the camera during surfaceDestroyed - view should be gone this.releaseCamera(); } /** * Release the camera from use */ public void releaseCamera() { if (camera != null) { camera.release(); camera = null; } } }

参考文献：

我知道这一点，因为我在这里的一个大型Google Glass存储库中工作：https://github.com/jaredsburrows/OpenQuartz。

请在此处查看我的个人相机示例：https://github.com/jaredsburrows/OpenQuartz/tree/master/examples/CameraPreview。

其他问题：java.lang.RuntimeException: Fail to Connect to camera service

我无法打开Google Glass相机

1 个答案:

问题：

实施例

参考文献：

我无法打开Goog​​le Glass相机

1 个答案:

问题：

实施例

参考文献：

我无法打开Google Glass相机