Android 使用Zxing实现二维码，横切竖屏预览扭曲变开的解决方法

在使用Zxing 实现app 的二维码功能时，发现在切换着竖屏扫码时，显示的预览的物件会被拉伸变形了。此时，可以通过下面的方式来修复这个bug。
1） 找到你添加的com.zxing.camera包下的CameraConfigurationManager.java文件下的initFromCameraParameters方法，如下图

  void initFromCameraParameters(Camera camera) {
    Camera.Parameters parameters = camera.getParameters();
    previewFormat = parameters.getPreviewFormat();
    previewFormatString = parameters.get("preview-format");
    Log.d(TAG, "Default preview format: " + previewFormat + '/' + previewFormatString);
    WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    Display display = manager.getDefaultDisplay();
    screenResolution = new Point(display.getWidth(), display.getHeight());
    Log.d(TAG, "Screen resolution: " + screenResolution);
    cameraResolution = getCameraResolution(parameters, screenResolution);
    Log.d(TAG, "Camera resolution: " + screenResolution);
  }

2）,将上边方法的替换成下面所示的方法

  void initFromCameraParameters(Camera camera) {
        Camera.Parameters parameters = camera.getParameters();
        previewFormat = parameters.getPreviewFormat();
        previewFormatString = parameters.get("preview-format");
        Log.d(TAG, "Default preview format: " + previewFormat + '/' + previewFormatString);
        WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = manager.getDefaultDisplay();
        screenResolution = new Point(display.getWidth(), display.getHeight());
        Log.d(TAG, "Screen resolution: " + screenResolution);
        Point screenResolutionForCamera = new Point();
        screenResolutionForCamera.x = screenResolution.x;
        screenResolutionForCamera.y = screenResolution.y;
        if (screenResolution.x < screenResolution.y) {
            screenResolutionForCamera.x = screenResolution.y;
            screenResolutionForCamera.y = screenResolution.x;
        }
        cameraResolution = getCameraResolution(parameters, screenResolutionForCamera);
        Log.d(TAG, "Camera resolution: " + screenResolution);
    }

由两段代码块可看，我们主要是添加修改了以下的代码，也即是我们将先前设置的横屏模式下的点的坐标在切换屏时，进行了对调。从而保证了我们在切换屏时，预览的图像大小始终是我们设置的屏幕分辨率大小。

Point screenResolutionForCamera = new Point();
        screenResolutionForCamera.x = screenResolution.x;
        screenResolutionForCamera.y = screenResolution.y;
        if (screenResolution.x < screenResolution.y) {
            screenResolutionForCamera.x = screenResolution.y;
            screenResolutionForCamera.y = screenResolution.x;
        }
         cameraResolution = getCameraResolution(parameters, screenResolutionForCamera);