在 android 个相机上添加数据

Question

我正在尝试制作一个 android 应用程序，它可以打开相机、启动计时器并在相机上显示计时器（当前时间，每秒刷新一次）。

我设法制作了一个计时器，我设法启动了相机，但我无法弄清楚如何以及在何处添加计时器数据。

我通过单击按钮启动相机，代码如下所示：

 public void onClick(View v) {
        Intent intent = new   Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, IMAGE_CAPTURE);
    }

我的计时器 class 此刻在 TextView 上打印数据，如下所示：

    runOnUiThread(new Runnable(){
            @Override
            public void run() {
                textCounter.setText(strDate);
            }});

如有任何帮助，我们将不胜感激！

Answer 1

this github link 上有一个自定义相机 class 的示例。

我会尝试在下面解释您需要做什么。

对于您的布局，您可以使用此代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <FrameLayout
        android:id="@+id/cameraPreview"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >
    <TextView
        android:id="@+id/timerTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center" /> </FrameLayout> </LinearLayout>

将以下权限添加到您的清单中：

 <uses-feature android:name="android.hardware.camera" />
 <uses-permission android:name="android.permission.CAMERA" />

创建相机 activity 并预览 class:

public class CameraActivity extends Activity implements Camera.PictureCallback,
        SurfaceHolder.Callback {
    private Camera camera;
    private SurfaceView cameraPreview;

    private FrameLayout frameLayoutCameraPreview;

    private int currentCameraID = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.activity_camera);

        cameraPreview = new SurfaceView(this);
        cameraPreview.setKeepScreenOn(true);

        initFormElements();

        /* get the current camera id */
        currentCameraID = Camera.CameraInfo.CAMERA_FACING_BACK;

        /* show the camera */
        showCamera();
    }


    @SuppressWarnings("deprecation")
    private void initFormElements() {

        frameLayoutCameraPreview = (FrameLayout) findViewById(R.id.cameraPreview);

        // initialize your textview here as well

        /* configure surface holder */
        /*
         * Install a SurfaceHolder.Callback so we get notified when the
         * underlying surface is created and destroyed.
         */

        surfaceHolder = cameraPreview.getHolder();
        surfaceHolder.addCallback(this);
        /* deprecated setting, but required on Android versions prior to 3.0 */
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    }

    private void showCamera() {

        /* create an instance of Camera */
        setCamera(getCameraInstance(currentCameraID));

    }

private void setCamera(Camera camera) {

        if (camera == this.camera) {
            return;
        }

        this.camera = camera;

        if (camera != null) {

            /* set the camera display orientation */
            setCameraDisplayOrientation(CameraActivity.this, currentCameraID,
                    camera);

            // get Camera parameters
            Camera.Parameters params = camera.getParameters();

            List<String> focusModes = params.getSupportedFocusModes();
            if (focusModes != null) {
                if (focusModes
                        .contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
                    // set the focus mode
                    params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                    camera.setParameters(params);
                }
            }

            try {
                camera.setPreviewDisplay(surfaceHolder);
            } catch (IOException e) {
                Log.i("IOException", e.getMessage());
            }

            // Important: Call startPreview() to start updating the preview
            // surface. Preview must be started before you can take a picture.
            camera.startPreview();
        }
    }


/* A safe way to get an instance of the Camera object. */
private Camera getCameraInstance(int cameraID) {
    Camera camera = null;
    try {
        /* attempt to get a Camera instance */
        camera = Camera.open(cameraID);
    } catch (Exception e) {
        /* Camera is not available (in use or does not exist) */
        Log.i("CameraActivity", "Error getting camera: " + e.getMessage());
        finish();
    }

    /* returns null if camera is unavailable */
    return camera;
}

/* SurfaceHolder.Callback interface methods */
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the
        // preview.
        try {
            camera.setPreviewDisplay(holder);
            camera.startPreview();
        } catch (IOException e) {
            Log.d("CameraActivity",
                    "Error setting camera preview: " + e.getMessage());
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (holder.getSurface() == null) {
            // preview surface does not exist
            Log.d("CameraActivity", "SurfaceHolder is null");
            return;
        }

        // stop preview before making changes
        try {
            camera.stopPreview();
        } catch (Exception e) {
            // ignore: tried to stop a non-existent preview
            Log.d("CameraActivity",
                    "Error stopping camera preview: " + e.getMessage());
        }

        try {

                camera.setPreviewDisplay(holder);
                camera.startPreview();

        } catch (Exception e) {
            Log.d("CameraActivity",
                    "Error starting camera preview: " + e.getMessage());
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // Take care of releasing the Camera preview in your activity.
        if (camera != null) {
            camera.stopPreview();
            camera.release();
        }
    }

/* Camera.PictureCallback interface method */
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        // save the image asynchronously here

    }

    }

图片拍完后，要异步保存图片：

 private class SaveImageTask extends AsyncTask<byte[], Void, Void> {

    @Override
    protected Void doInBackground(byte[]... data) {
        FileOutputStream outStream = null;

        // Write to SD Card
        try {
            File sdCard = Environment.getExternalStorageDirectory();
            File dir = new File (sdCard.getAbsolutePath() + "/camtest");
            dir.mkdirs();               

            String fileName = String.format("%d.jpg", System.currentTimeMillis());
            File outFile = new File(dir, fileName);

            outStream = new FileOutputStream(outFile);
            outStream.write(data[0]);
            outStream.flush();
            outStream.close();

            Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length + " to " + outFile.getAbsolutePath());

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }
        return null;
    }

}

在 android 个相机上添加数据

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