根据项目开发的需要，系统为的UIPageControl的样式可能并不是我们想要的，这个时候我们就需要根据自己实际需求情况自定义UIPageControl
例如：

自定义方式1

自定义方式2

那么这种效果怎么实现呢？别的不多说，我们上代码代码：
首先：我们自定义一个类：CustomPageControl类 其父类是UIView

.h

#import <UIKit/UIKit.h>
@interface CustomPageControl : UIView

typedef enum: NSInteger
{
    //默认类型/圆形
    PageControlStyleCircle = 0,
    //正方形
    PageControlStyleSquare,
    
    //......
}PageControlStyle;

@property(nonatomic,assign)NSInteger numberOfPags; //点个数
@property(nonatomic,assign)NSInteger currentPags;  //当前点位置

@property(nonatomic,strong)UIColor *selectedColor; //选中的色
@property(nonatomic,strong)UIColor *backPageColor; //背景色

@property(nonatomic,assign)PageControlStyle pageControlStyle;//类别

//自定义初始化方法
-(id)initWithFrame:(CGRect)frame pageControlStyle:(PageControlStyle)pageControlStyle ;
@end

.m

初始化

-(id)initWithFrame:(CGRect)frame pageControlStyle:(PageControlStyle)pageControlStyle{
    if (self = [super initWithFrame:frame]) {
        //默认设置
        _backPageColor = [UIColor darkTextColor];
        _selectedColor = [UIColor whiteColor];
        _pageControlStyle = pageControlStyle;
        _currentPags = 0;
    }
    return self;
}

设置PageView

-(void)setNumberOfPags:(NSInteger)numberOfPags{
    if (_numberOfPags != numberOfPags) {
        _numberOfPags = numberOfPags;
        CGFloat margin = 10;
        NSLog(@"%f",self.frame.size.width);
        CGFloat width = self.frame.size.width - (numberOfPags - 1)*margin;
        CGFloat pointWidth = width / numberOfPags;
        
        for (int i = 0; i < numberOfPags; i++) {
            UIView *aview = [[UIView alloc]init];
            aview.frame = CGRectMake((margin + pointWidth) * i, 0, pointWidth, pointWidth);
            aview.backgroundColor = _backPageColor;
            switch (_pageControlStyle) {
                case PageControlStyleCircle:
                    aview.layer.cornerRadius = pointWidth / 2 ;
                    aview.layer.masksToBounds = YES;
                    break;
                   case PageControlStyleSquare:
                    break;
                default:
                    break;
            }
            [self addSubview:aview];
            
            /**
             *  设置cuurrentPag
             */
            if (i == 0) {
                if (_selectedColor) {
                    aview.backgroundColor = _selectedColor;
                }
                else
                {
                    aview.backgroundColor = [UIColor whiteColor];
                }
            }
        }
    }
}

当前的currentPage

-(void)setCurrentPags:(NSInteger)currentPags{
    if (_currentPags != currentPags) {
        _currentPags = currentPags;
        if (self.subviews.count) {
            for (UIView *aView in self.subviews) {
                aView.backgroundColor = _backPageColor;
            }
            UIView *aView = self.subviews[_currentPags];
            aView.backgroundColor = _selectedColor;
        }
    }
}

设置选中的颜色

-(void)setSelectedColor:(UIColor *)selectedColor{
    if (_selectedColor != selectedColor) {
        _selectedColor = selectedColor;
        if (self.subviews.count) {
            UIView *aView = self.subviews[_currentPags];
            aView.backgroundColor = _selectedColor;
        }
    }
}

设置背景色

-(void)setbackgroundColor:(UIColor *)backgroundColor{
    if (_backPageColor != backgroundColor) {
        _backPageColor = backgroundColor;
        if (self.subviews.count != 0) {
            for (UIView *aView in self.subviews) {
                aView.backgroundColor = _backPageColor;
            }
            UIView *aView = self.subviews[_currentPags];
            aView.backgroundColor = _selectedColor;
        }
    }
}

以上是对UIPageControl的自定义 那么使用起来就更简单了
我们导入头文件

#import "CustomPageControl.h"

@interface ViewController ()<UIScrollViewDelegate>
{    
    CustomPageControl *pageControl;
    UIScrollView *scrollView;
}
@end
#define screenWidth self.view.frame.size.width
#define screenHeight self.view.frame.size.height

在viewDidLoad 中：

    scrollView = [[UIScrollView alloc]init];
    scrollView.frame= CGRectMake(0, 0, screenWidth, screenHeight);
    scrollView.contentSize = CGSizeMake(5 * screenWidth, screenHeight);
    scrollView.delegate =self;
    scrollView.pagingEnabled = YES;
    scrollView.bounces = NO;
    [self.view addSubview:scrollView];
    
    
    for (int i = 1; i <= 5; i++) {
        UIImageView *aImageView = [[UIImageView alloc]init];
        aImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d",i]];

        aImageView.frame = CGRectMake((i - 1) * screenWidth, 0, screenWidth, screenHeight);
        aImageView.contentMode = UIViewContentModeScaleAspectFit;
        [scrollView addSubview:aImageView];
    }
    pageControl = [[CustomPageControl alloc]initWithFrame:CGRectMake(100, screenHeight - 50, screenWidth - 200, 35) pageControlStyle:PageControlStyleSquare];
//    pageControl.backgroundColor = [UIColor redColor];
    pageControl.backPageColor = [UIColor cyanColor];
    pageControl.selectedColor = [UIColor blackColor];
    pageControl.numberOfPags = 5;
    [self.view addSubview:pageControl];

由于 scrollView.delegate =self; 我们实现UIScrollViewDelegate中的scrollViewDidScroll: 方法 用来监听在scrollView滚动的时候的偏移量 来改变pageControl的显示样式：

- (void)scrollViewDidScroll:(UIScrollView *)scrollVi
{
    CGFloat size = scrollView.contentOffset.x;
    NSInteger index = (size/scrollView.frame.size.width) + 0.5;
    NSLog(@"%f-%ld",size,index);
    pageControl.currentPags = index;
}

此时 运行程序 就是我们想要看到的效果了。。。