UIPageControl tips 的分页图片的设置

- (void)setPageImage:(UIImage *)image andCurrentPageImage:(UIImage *)currentImage {
    if (!image || !currentImage) return;
    self.pageImageSize = image.size;
    [self.pageControl setValue:currentImage forKey:@"_currentPageImage"];
    [self.pageControl setValue:image forKey:@"_pageImage"];
}