zxing调整扫码框大小和近距离扫码问题

使用zxing扫描二维码，需要远距离扫描才能识别，用户体验不好，在网上搜了一下，发现一个解决办法，最起码现在是可以近距离扫描了。 
1.修改扫描框大小，使用各种分辨率 
CameraManager.java类中修改

public Rect getFramingRect() {
      if (framingRect == null) {
          if (camera == null) {
            return null;
          }
        Point screenResolution = configManager.getScreenResolution();
        if (screenResolution == null) {
          return null;
        }

            /* 扫描框修改 */
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        int width = (int) (metrics.widthPixels * 0.6);
        int height = (int) (width * 0.9);


        int leftOffset = (screenResolution.x - width) / 2;
        int topOffset = (screenResolution.y - height) / 3;
        framingRect = new Rect(leftOffset, topOffset, leftOffset + width,
                topOffset + height);
        Log.d(TAG, "Calculated framing rect: " + framingRect);
      }
    return framingRect;

  }

修改扫描距离 

CameraConfigurationManager.java

void setDesiredCameraParameters(Camera camera) {
    Camera.Parameters parameters = camera.getParameters();
    List supportedPreviewSizes = parameters.getSupportedPreviewSizes();
    int position =0;
    if(supportedPreviewSizes.size()>2){
      position=supportedPreviewSizes.size()/2+1;//supportedPreviewSizes.get();
    }else {
      position=supportedPreviewSizes.size()/2;
    }

    int width = supportedPreviewSizes.get(position).width;
    int height = supportedPreviewSizes.get(position).height;
    Log.d(TAG, "Setting preview size: " + cameraResolution);
    camera.setDisplayOrientation(90);
    cameraResolution.x=width;
    cameraResolution.y=height;
    parameters.setPreviewSize(width,height);
    setFlash(parameters);
    setZoom(parameters);
    //setSharpness(parameters);
    camera.setParameters(parameters);
  }