UI基础 UIScrollView + PageControl

root.m

#import "RootViewController.h"
//1.签订协议
@interface RootViewController ()<UIScrollViewDelegate>
{
    UIPageControl *PControl;
    UIScrollView* sv;
    
}
@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    sv=[[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, 375, 667)];
    
    sv.backgroundColor=[UIColor yellowColor];
    [self.view addSubview:sv];
    
    //设置大小 多大才能装下四张图片
    sv.contentSize=CGSizeMake(375*4, 667);
    //把图片装进去
    for(int i=1; i<=4; i++){
        NSString* name =[NSString stringWithFormat:@"%d.jpg",i];
        UIImage *image =[UIImage imageNamed:name];
        UIImageView* imageV=[[UIImageView alloc] initWithFrame:CGRectMake(375*(i-1), 0, 375, 667)];
        
        imageV.image=image;
        [sv addSubview:imageV];
        
        
        //分页显示
        sv.pagingEnabled=YES;
        //是否允许反弹
        sv.bounces=NO;
        // 修改滚动条样式
        sv.indicatorStyle=UIScrollViewIndicatorStyleWhite;
        //隐藏滚动条
        sv.showsHorizontalScrollIndicator=NO;
        sv.showsVerticalScrollIndicator=NO;
        //滑动到指定位置
        sv.contentOffset=CGPointMake(375, 0);
//        2.构造方法
        sv.delegate=self;
//         创建下边四个小点 （页面控制）
        PControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 600, 375, 50)];
        
        PControl.backgroundColor=[UIColor redColor];
        [self.view addSubview:PControl];
        // 几个点
        PControl.numberOfPages=4;
        //选中点点颜色
        PControl.currentPageIndicatorTintColor=[UIColor greenColor];
        
        //为选中点的颜色
        PControl.pageIndicatorTintColor=[UIColor yellowColor];
        
        //添加事件 UIControl 自带属性
        [PControl addTarget:self action:@selector(PageCon:) forControlEvents:UIControlEventValueChanged];
        
        
        
    
    }
    
    
}
-(void)PageCon:(UIPageControl *)p
{
    NSLog(@"%ld",p.currentPage);
    //我们知道当前小点的位置 通过偏移量设置scrollview的位置就可以了
//    sv.contentOffset=CGPointMake(375*p.currentPage, 0);
    [sv setContentOffset:CGPointMake(375*p.currentPage, 0)
                animated:YES];
    
    
}


//3.代理方法
//UIScrollView 的代理方法 之要移动 就会产生方法
//偏移量 / 宽度 = 滑动了多少
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    NSLog(@"动了");
    
    
}


-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    NSLog(@"开始拖拽");
        
}

-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

{
    NSLog(@"结束拖拽");
    
}

-(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
    
    NSLog(@"开始减速");
}

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    NSLog(@"结束减速");
    int number =(int)scrollView.contentOffset.x/375;
    NSLog(@"%d",number+1);
    
    //设置底部的小点移动到指定的位置
    PControl.currentPage=number;
    
}


@end