Android 自定义Camera

地址：​​https://github.com/danfengfirst/Camera​​

Demo说明：

1、Demo包含了自定义的矩形View ，一般这种矩形放个图片就可以了，这里因为对长宽比有特别的需求，希望在不同屏幕保持相同的长宽比，因此这里进行了自定义，自定义部分可以换成图片。另外，这个Demo并不是只拍摄矩形区域。

2、Demo中将Camera直接放到了自定义的SurfaceView中。

3、触摸聚焦

//设置触摸事件监听
            setOnTouchListener(new OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    if (event.getAction() == MotionEvent.ACTION_DOWN) {
                        Point point = new Point();
                        point.x = (int) event.getX();
                        point.y = (int) event.getY();
                        onFocus(point, mCameraAutoFocusCallBack);
                    }
                    return true;
                }
            });

//触摸对焦
    protected boolean onFocus(Point point, Camera.AutoFocusCallback callback) {
        if (mCamera == null) {
            return false;
        }
        Camera.Parameters parameters = null;
        try {
            parameters = mCamera.getParameters();
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        //不支持设置自定义聚焦，则使用自动聚焦，返回

        if(Build.VERSION.SDK_INT >= 14) {

            if (parameters.getMaxNumFocusAreas() <= 0) {
                return focus(callback);
            }

            Log.i(TAG, "onCameraFocus:" + point.x + "," + point.y);

            //定点对焦
            List<Camera.Area> areas = new ArrayList<Camera.Area>();
            int left = point.x - 300;
            int top = point.y - 300;
            int right = point.x + 300;
            int bottom = point.y + 300;
            left = left < -1000 ? -1000 : left;
            top = top < -1000 ? -1000 : top;
            right = right > 1000 ? 1000 : right;
            bottom = bottom > 1000 ? 1000 : bottom;
            areas.add(new Camera.Area(new Rect(left, top, right, bottom), 100));
            parameters.setFocusAreas(areas);
            try {
                //使用的小米手机在设置聚焦区域的时候经常会出异常，看日志发现是框架层的字符串转int的时候出错了，
                //目测是小米修改了框架层代码导致，在此try掉，对实际聚焦效果没影响
                mCamera.setParameters(parameters);
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
                return false;
            }
        }


        return focus(callback);
    }

    private boolean focus(Camera.AutoFocusCallback callback) {
        try {
            mCamera.autoFocus(callback);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

4、最佳分辨率

/**
     * 获取最佳分辨率
     * @param sizes
     * @param w
     * @param h
     * @return
    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) h / w;
        if (sizes == null)
            return null;
        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;
        int targetHeight = h;
        for (Camera.Size size : sizes) {
            double ratio = (double) size.height / size.width;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
                continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }

        return

5、图片尺寸过小之类的问题可以通过重新构建bitmap来解决

关于自定义camera的文章网上也比较多就不多介绍了

ps:随便记一下github图片的显示方式,怕自己下次忘了

image](https://github.com/danfengfirst/Camera/raw/master/Screenshot_2018-02-03-11-53-57.png)