UIPageControl *pageControl = [[UIPageControl alloc] init];
pageControl.center = CGPointMake(w * 0.5, h - );
pageControl.bounds = CGRectMake(, , , ); // 一共显示多少个圆点(多少页)
pageControl.numberOfPages = ; // 设置非选中页的圆点颜色
pageControl.pageIndicatorTintColor = [UIColor redColor]; // 设置选中页的圆点颜色
pageControl.currentPageIndicatorTintColor = [UIColor blueColor]; // 禁止点击功能
pageControl.enabled = NO;