Zxing框架扫描框大小适配问题

Zxing框架进行二维码扫描时候会发现，随着分辨率的增加，扫描框会越来越小，SurfaceView扫描窗口就看不见了，我们可以自己定义扫描窗口的大小，以及适配屏幕问题。
      Zxing包中有个类CameraManager，它是来设置扫描框的大小
      扫描框框初始化数值

private static  int MIN_FRAME_WIDTH = 240;
private static  int MIN_FRAME_HEIGHT = 240;
private static  int MAX_FRAME_WIDTH = 480;
private static  int MAX_FRAME_HEIGHT = 360;

      此类里面有个getFramingRect方法用来设置扫描的框的大小，如果要修改扫描框的大小可以在这个方法里修改

public Rect getFramingRect() {
Point screenResolution = configManager.getScreenResolution();
if (framingRect == null) {
if (camera == null) {
return null;
}
int width = screenResolution.x * 3 / 4;
if (width < MIN_FRAME_WIDTH) {
width = MIN_FRAME_WIDTH;
} else if (width > MAX_FRAME_WIDTH) {
width = MAX_FRAME_WIDTH;
}
int height = screenResolution.y * 3 / 4;
if (height < MIN_FRAME_HEIGHT) {
height = MIN_FRAME_HEIGHT;
}
else if (height > MAX_FRAME_HEIGHT) {
height = MAX_FRAME_HEIGHT;
}
int leftOffset = (screenResolution.x - width) / 2;
int topOffset = (screenResolution.y - height) / 2;
framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
Log.d(TAG, "Calculated framing rect: " + framingRect);
}
return framingRect;
}

      要让扫描框适应不同的分辨率，我们需要根据分辨率将扫描矿的初始值转化就好。
      MIN_FRAME_WIDTH = Dp2Px(context,180);

      MIN_FRAME_HEIGHT =Dp2Px(context,180) ;

      MAX_FRAME_WIDTH = Dp2Px(context,280);

      MAX_FRAME_HEIGHT =Dp2Px(context,240) ;

     dp转为px的方法为

public static  int Dp2Px( Context context,float dp) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dp * scale + 0.5f);
}