我可以在不打开相机的情况下拍摄图像吗？

Question

我可以在不打开Android相机的情况下拍照吗？

我想从Android摄像头捕获图像，但是我不想打开摄像头预览？
有人可以在这里提供代码段帮助我吗？

Answer 1

这里有一个示例，说明如何在没有SurfaceView的情况下在背景中捕获图像。

 Intent front_translucent = new Intent(getApplication()
                        .getApplicationContext(), CameraService.class);
                front_translucent.putExtra("Front_Request", true);
                front_translucent.putExtra("Quality_Mode",
                        camCapture.getQuality());
                getApplication().getApplicationContext().startService(
                        front_translucent);


    public class CamerService extends Service implements
        SurfaceHolder.Callback {

    // Camera variables
    // a surface holder
    // a variable to control the camera
    private Camera mCamera;
    // the camera parameters
    private Parameters parameters;
    private Bitmap bmp;
    FileOutputStream fo;
    private String FLASH_MODE;
    private int QUALITY_MODE = 0;
    private boolean isFrontCamRequest = false;
    private Camera.Size pictureSize;
    SurfaceView sv;
    private SurfaceHolder sHolder;
    private WindowManager windowManager;
    WindowManager.LayoutParams params;
    public Intent cameraIntent;
    SharedPreferences pref;
    Editor editor;
    int width = 0, height = 0;

    /** Called when the activity is first created. */
    @Override
    public void onCreate() {
        super.onCreate();

    }

    private Camera openFrontFacingCameraGingerbread() {
        if (mCamera != null) {
            mCamera.stopPreview();
            mCamera.release();
        }
        int cameraCount = 0;
        Camera cam = null;
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        cameraCount = Camera.getNumberOfCameras();
        for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
            Camera.getCameraInfo(camIdx, cameraInfo);
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                try {
                    cam = Camera.open(camIdx);
                } catch (RuntimeException e) {
                    Log.e("Camera",
                            "Camera failed to open: " + e.getLocalizedMessage());
                    /*
                     * Toast.makeText(getApplicationContext(),
                     * "Front Camera failed to open", Toast.LENGTH_LONG)
                     * .show();
                     */
                }
            }
        }
        return cam;
    }

    private void setBesttPictureResolution() {
        // get biggest picture size
        width = pref.getInt("Picture_Width", 0);
        height = pref.getInt("Picture_height", 0);

        if (width == 0 | height == 0) {
            pictureSize = getBiggesttPictureSize(parameters);
            if (pictureSize != null)
                parameters
                        .setPictureSize(pictureSize.width, pictureSize.height);
            // save width and height in sharedprefrences
            width = pictureSize.width;
            height = pictureSize.height;
            editor.putInt("Picture_Width", width);
            editor.putInt("Picture_height", height);
            editor.commit();

        } else {
            // if (pictureSize != null)
            parameters.setPictureSize(width, height);
        }
    }

    private Camera.Size getBiggesttPictureSize(Camera.Parameters parameters) {
        Camera.Size result = null;

        for (Camera.Size size : parameters.getSupportedPictureSizes()) {
            if (result == null) {
                result = size;
            } else {
                int resultArea = result.width * result.height;
                int newArea = size.width * size.height;

                if (newArea > resultArea) {
                    result = size;
                }
            }
        }

        return (result);
    }