Android获取相机最佳预览大小和获取屏幕宽高

/**
 * 获取最佳预览大小
 *
 * @param parameters       相机参数
 * @param screenResolution 屏幕宽高
 * @return
 */
private Point getBestCameraResolution(Camera.Parameters parameters, Point screenResolution) {
    float tmp;
    float mindiff = 100f;
    float x_d_y = (float) screenResolution.x / (float) screenResolution.y;
    Size best = null;
    List<Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes();
    for (Size s : supportedPreviewSizes) {
        tmp = Math.abs(((float) s.height / (float) s.width) - x_d_y);
        if (tmp < mindiff) {
            mindiff = tmp;
            best = s;
        }
    }
    return new Point(best.width, best.height);
}

/**
 * 获取屏幕宽度和高度，单位为px
 *
 * @param context
 * @return
 */
public static Point getScreenMetrics(Context context) {
    DisplayMetrics dm = context.getResources().getDisplayMetrics();
    return new Point(dm.widthPixels, dm.heightPixels);
}