本章实现效果一:
核心代码:
#import "ViewController.h" @interface ViewController ()<UIScrollViewDelegate> @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; self.navigationItem.title = @"滚动视图"; [self createScrollView]; } /** * 滚动视图只是将比它大的UIImageView视图,通过拖拽效果,将UIImageView上的图片信息完整的展示给用户 * 为了让滚动效果明显,添加图片视图的宽或者高至少比滚动视图的宽高多一个像素 */ - (void)createScrollView { //创建对象 UIScrollView * scrollView = [[UIScrollView alloc] init]; //显示位置 scrollView.frame = CGRectMake(10, 70, self.view.bounds.size.width-20, 400); //添加背景颜色 scrollView.backgroundColor = [UIColor orangeColor]; //添加UIImageView UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 600, 500)]; imageView.image = [UIImage imageNamed:@"timg.jpg"]; [scrollView addSubview:imageView]; //设置滚动视图的滚动范围, 内容视图的大小 scrollView.contentSize = imageView.frame.size; //关闭自动调节显示位置的属性 self.automaticallyAdjustsScrollViewInsets = NO; //关闭边框回弹效果 scrollView.bounces = NO; //隐藏滚动条 scrollView.showsHorizontalScrollIndicator = NO; scrollView.showsVerticalScrollIndicator = NO; //设置内容视图的偏移位置,默认内容视图显示在滚动视图区域的坐标是在内容视图的(0,0)点位置 scrollView.contentOffset = CGPointMake(200, 100); //设置滚动视图的内容视图的缩放效果 scrollView.delegate = self; //设置缩放的倍数 scrollView.minimumZoomScale = 1.0; scrollView.maximumZoomScale = 3.0; [self.view addSubview:scrollView]; } #pragma mark - UIScrollViewDelegate /** * 最常用的协议方法，没有时间点反复调用,当滚动视图滚动时,一直调用 */ - (void)scrollViewDidScroll:(UIScrollView *)scrollView { NSLog(@"x = %f_____y = %f",scrollView.contentOffset.x,scrollView.contentOffset.y); } /** * 设置滚动视图的缩放效果 */ - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{ return [[scrollView subviews] objectAtIndex:0]; } /** * 滚动视图拖拽开始调用该方法 */ - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView { //获取的是该方法的名称 NSLog(@"%@",NSStringFromSelector(_cmd)); } /** * 滚动视图拖拽结束调用该方法 * 不能在该方法中获取最终滚动视图停止内容视图的偏移位置的值,也就是contentoffSet的值 * 因为滚动视图拖拽结束的时候,还要经历一个内容视图缓慢减速停止的方法,应该在减速停止的方法里获取contentoffSet的值 */ - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate { NSLog(@"%@",NSStringFromSelector(_cmd)); } /** * 滚动视图减速停止调用的方法 */ - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { NSLog(@"%@",NSStringFromSelector(_cmd)); } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end本章实现效果二:
核心代码:
#import "ViewController.h" #import "HTConfig.h" @interface ViewController ()<UIScrollViewDelegate> @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; [self createScrollView]; } - (void)createScrollView { UIScrollView * scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; scrollView.bounces = NO; scrollView.showsHorizontalScrollIndicator = NO; scrollView.contentSize = CGSizeMake(7 * SCREEN_width, SCREEN_height); //设置内容视图初始状态下的偏移位置 scrollView.contentOffset = CGPointMake(SCREEN_width, 0); for (int i = 0; i < 7; i++) { UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(SCREEN_width * i, 0, SCREEN_width, SCREEN_height)]; if (i == 0) { imageView.image = [UIImage imageNamed:@"5.png"]; }else if (i == 6) { imageView.image = [UIImage imageNamed:@"1.png"]; }else { imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.png",i]]; } [scrollView addSubview:imageView]; } scrollView.pagingEnabled = YES; //设置代理 scrollView.delegate = self; [self.view addSubview:scrollView]; } #pragma mark - UIScrollViewDelegate - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { if (scrollView.contentOffset.x == 6 * SCREEN_width) { scrollView.contentOffset = CGPointMake(SCREEN_width, 0); } else if (scrollView.contentOffset.x == 0) { scrollView.contentOffset = CGPointMake(5 * SCREEN_width, 0); } } @end本章实现效果三:
核心代码:
#import "ViewController.h" @interface ViewController ()<UIScrollViewDelegate> @end @implementation ViewController { UIScrollView * _scrollView; UIPageControl * _pageCtr; } - (void)viewDidLoad { [super viewDidLoad]; self.navigationItem.title = @"分页控件"; [self createUI]; } - (void)createUI { self.automaticallyAdjustsScrollViewInsets = NO; [self createScrollView]; [self createPageController]; } - (void)createScrollView { _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(10, 70, self.view.bounds.size.width-20, 350)]; _scrollView.contentSize = CGSizeMake((self.view.bounds.size.width-20) * 5, 350); _scrollView.backgroundColor = [UIColor cyanColor]; for (int i = 0; i < 5; i++) { UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(i * (self.view.bounds.size.width-20), 0, self.view.bounds.size.width-20, 350)]; imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.png",i+1]]; [_scrollView addSubview:imageView]; } _scrollView.showsHorizontalScrollIndicator = NO; _scrollView.bounces = NO; //分页效果 _scrollView.pagingEnabled = YES; //设置代理 _scrollView.delegate = self; //缩放比例 _scrollView.minimumZoomScale = 1.0; _scrollView.maximumZoomScale = 3.0f; [self.view addSubview:_scrollView]; } - (void)createPageController { //创建分页控件 _pageCtr = [[UIPageControl alloc] initWithFrame:CGRectMake(50, 350 - 30, 200, 30)]; //背景颜色 _pageCtr.backgroundColor = [UIColor blackColor]; //设置分页控件的总页数 _pageCtr.numberOfPages = 5; //设置初始化分页空间的页码 _pageCtr.currentPage = 0; [self.view addSubview:_pageCtr]; } #pragma mark - UIScrollViewDelegate - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView { NSLog(@"%@",[[_scrollView subviews] objectAtIndex:_pageCtr.currentPage]); return [[_scrollView subviews] objectAtIndex:_pageCtr.currentPage]; } //减速停止 - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { //获取当前的显示页为第几页 int currentNum = _scrollView.contentOffset.x/_scrollView.frame.size.width; //设置当前的显示页码 _pageCtr.currentPage = currentNum; } @enddemo地址
