如何实现 Android 相机的自动对焦,而且是连续自动对焦的。当然直接调用系统相机就不用说了,那个很简单的。下面我们主要来看看如如何自己实现一个相机,并且实现自动连续对焦。
代码如下:
- public class MainActivity extends Activity {
- private SurfaceView surfaceView;
- private SurfaceHolder surfaceHolder;
- private boolean flag = false;
- private String fileUrl="";
- Camera camera;
- Camera.Parameters parameters;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- surfaceView = (SurfaceView) findViewById(R.id.surfaceView1);
- Button button=(Button) findViewById(R.id.takepicture);
- surfaceHolder = surfaceView.getHolder();
- surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
- surfaceHolder.setKeepScreenOn(true);
- surfaceView.setFocusable(true);
- surfaceView.setBackgroundColor(TRIM_MEMORY_BACKGROUND);
- surfaceHolder.addCallback(new Callback() {
- @Override
- public void surfaceDestroyed(SurfaceHolder holder) {
- // TODO Auto-generated method stub
- camera.stopPreview();
- camera.release();
- camera=null;
- }
- @Override
- public void surfaceCreated(SurfaceHolder holder) {
- // TODO Auto-generated method stub
- if(null==camera){
- camera=Camera.open();
- try {
- camera.setPreviewDisplay(surfaceHolder);
- initCamera();
- camera.startPreview();
- } catch (IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- }
- @Override
- public void surfaceChanged(SurfaceHolder holder, int format, int width, int height){
- //实现自动对焦
- camera.autoFocus(new AutoFocusCallback() {
- @Override
- public void onAutoFocus(boolean success, Camera camera) {
- if(success){
- initCamera();//实现相机的参数初始化
- camera.cancelAutoFocus();//只有加上了这一句,才会自动对焦。
- }
- }
- });
- }
- });
- }
- //相机参数的初始化设置
- private void initCamera()
- {
- parameters=camera.getParameters();
- parameters.setPictureFormat(PixelFormat.JPEG);
- //parameters.setPictureSize(surfaceView.getWidth(), surfaceView.getHeight()); // 部分定制手机,无法正常识别该方法。
- parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
- parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);//1连续对焦
- setDispaly(parameters,camera);
- camera.setParameters(parameters);
- camera.startPreview();
- camera.cancelAutoFocus();// 2如果要实现连续的自动对焦,这一句必须加上
- }
- //控制图像的正确显示方向
- private void setDispaly(Camera.Parameters parameters,Camera camera)
- {
- if (Integer.parseInt(Build.VERSION.SDK) >= 8){
- setDisplayOrientation(camera,90);
- }
- else{
- parameters.setRotation(90);
- }
- }
- //实现的图像的正确显示
- private void setDisplayOrientation(Camera camera, int i) {
- Method downPolymorphic;
- try{
- downPolymorphic=camera.getClass().getMethod("setDisplayOrientation", new Class[]{int.class});
- if(downPolymorphic!=null) {
- downPolymorphic.invoke(camera, new Object[]{i});
- }
- }
- catch(Exception e){
- Log.e("Came_e", "图像出错");
- }
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- // Inflate the menu; this adds items to the action bar if it is present.
- getMenuInflater().inflate(R.menu.main, menu);
- return true;
- }
- }
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