surfaceView实现拍照功能

1.布局中只有一个SurfaceView和Button，初始SurfaceView通过surface.getHolder获得SurfaceHolder类

       SurfaceView sfv= (SurfaceView) findViewById(R.id.surfaceView);
        holder = sfv.getHolder();
        //指定类型
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        //指定回调接口
        holder.addCallback(new A());

2.回调接口。这里setPictureSize(width，height)宽高并不能随意设置，必须属于

myParameters.getSupportedPictureSizes()

中的，在该回调中并设置了

cam.autoFocus(mAutoFocusCallback);
实现cam的聚焦功能。

myParameters.set("jpeg-quality", 10);这里设置的10使得图片最终质量较差。

private class A implements SurfaceHolder.Callback {
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            if(cam!=null){
                cam.release();
            }
            cam = Camera.open(0);
            try {
                 myParameters = cam.getParameters();
                 myParameters.setPictureSize(myParameters.getSupportedPictureSizes().get(0).width,myParameters.getSupportedPictureSizes().get(0).height);
                 for(int i=0;i<myParameters.getSupportedPictureSizes().size();i++){

                    Log.d(TAG, "surfaceCreated:  width: "+myParameters.getSupportedPictureSizes().get(i).width+"height:"+myParameters.getSupportedPictureSizes().get(i).height);
                }
                myParameters.setFocusMode("auto");
                myParameters.set("jpeg-quality", 10);
                cam.setParameters(myParameters);

                cam.setPreviewDisplay(holder);
                cam.setDisplayOrientation(90);
                cam.startPreview();
                cam.autoFocus(mAutoFocusCallback);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

        }

        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {

        }
    }

3.cam.autoFocus(mAutoFocusCallback)中的回调

  private Camera.AutoFocusCallback mAutoFocusCallback=new Camera.AutoFocusCallback() {
        @Override
        public void onAutoFocus(boolean success, Camera camera) {

        }
    };

4.在Button点击事件中实现拍照响应

 cam.takePicture(null,null,null,new B());

5.B回调，压缩图片，并保存

 private class B implements Camera.PictureCallback {

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            try {
                Bitmap a= BitmapFactory.decodeByteArray(data,0,data.length);

                String fileAdress=Environment.getExternalStorageDirectory()+File.separator+"AA"+File.separator+photoFileName;

                FileOutputStream out=new FileOutputStream(new File(fileAdress));
                //压缩
                a.compress(Bitmap.CompressFormat.JPEG,100,out);
                Toast.makeText(PhotoActivity.this,"",Toast.LENGTH_SHORT).show();

                if(cam!=null){
                    cam.release();
                }
              finish();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

6.给surfaceView加上点击事件，点击时，开启聚焦

 sfv.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                cam.autoFocus(mAutoFocusCallback);
                return false;
            }
        });