Android 如何在摄像头预览的背景上加上一个手指可拖动的调节框？

问题描述

请问调节框该如何绘制？是在SufaceView 中绘制么？手指拖动如何实现？

启动拍照功能后，下面是摄像头预览的背景(模拟器的)，在这个背景上加上一个调节框

Activity代码

public class PickActivity extends AppCompatActivity { private Button mBtnPick; private SurfaceView mSvView; private SurfaceHolder.Callback mCallback; private Camera mCamera; @Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_pick);initView();mCallback = new SurfaceHolder.Callback() { @Override public void surfaceCreated(SurfaceHolder holder) {startCamera(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) {stopCamera(); }};mSvView.getHolder().addCallback(mCallback);mBtnPick.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {mCamera.takePicture(null, null, new Camera.PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) {File path = new File(Environment.getExternalStorageDirectory(), 'test');if (!path.exists()) { path.mkdirs();}File fileName = new File(path, 'test.jpg');try { FileOutputStream fos = new FileOutputStream(fileName); fos.write(data); fos.flush(); fos.close();} catch (IOException e) { e.printStackTrace();} }}); }}); } private void stopCamera() {mCamera.stopPreview();mCamera.release();mCamera = null; } private void startCamera() {mCamera = Camera.open();try { mCamera.setPreviewDisplay(mSvView.getHolder()); mCamera.setDisplayOrientation(90); mCamera.startPreview();} catch (IOException e) { e.printStackTrace();} } private void initView() {mBtnPick = (Button) findViewById(R.id.id_btn_pick);mSvView = (SurfaceView) findViewById(R.id.id_sv_camera); }}

问题解答

添加seekBar