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素材代码地址:http://blog.csdn.net/u013357243/article/details/44646873
原文地址:http://blog.csdn.net/u013357243?viewmode=contents
先看效果
代码
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原文:http://blog.csdn.net/u013357243?viewmode=contents
// NYViewController.m
// 05 - 图片轮播器
//
// Created by apple on 15-3-25.
// Copyright (c) 2015年 znycat. All rights reserved.
//
#import "NYViewController.h"
#define kImageCount 5
@interface NYViewController () <UIScrollViewDelegate>
@property (nonatomic, strong) UIScrollView *scrollView;
@property (nonatomic, strong) UIPageControl *pageControl;
@property (nonatomic, strong) NSTimer *timer;
@end
@implementation NYViewController
//懒加载加载scrollView
-(UIScrollView *)scrollView
{
if (_scrollView == nil) {
_scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 20, 300, 130)];
_scrollView.backgroundColor = [UIColor redColor];
[self.view addSubview:_scrollView];
//contentSize
//高度为0 只水平滚动
self.scrollView.contentSize = CGSizeMake(kImageCount * _scrollView.bounds.size.width, 0);
//取消弹簧效果
_scrollView.bounces = NO;
//取消滚动条
_scrollView.showsHorizontalScrollIndicator = NO;//水平
_scrollView.showsVerticalScrollIndicator = NO;//竖直
//要分页
_scrollView.pagingEnabled = YES;
//设置代理
_scrollView.delegate = self;
}
return _scrollView;
}
-(UIPageControl *)pageControl
{
if (_pageControl == nil) {
//分页控件,本质上和scrollView没有任何关系,是两个独立的控件
_pageControl = [[UIPageControl alloc]init];
//总页数
_pageControl.numberOfPages = kImageCount;
//控件尺寸
CGSize size = [_pageControl sizeForNumberOfPages:kImageCount];
_pageControl.bounds = CGRectMake(0, 0, size.width, size.height);
_pageControl.center = CGPointMake(self.view.center.x, 130);
//设置颜色
_pageControl.pageIndicatorTintColor = [UIColor redColor];
_pageControl.currentPageIndicatorTintColor = [UIColor blackColor];
[self.view addSubview:_pageControl];
//添加监听方法
/**在OC中,绝大多数“继承UIControl控件”,都可以监听UIControlEventValueChanged事件,只有button除外,button是点得,是touchup。。。*/
[_pageControl addTarget:self action:@selector(pageChanged:) forControlEvents:UIControlEventValueChanged];
}
return _pageControl;
}
//分页控件的监听方法
-(void)pageChanged:(UIPageControl *)page
{
//根据页数,调整滚动视图中得图片位置contentOffset
CGFloat x = page.currentPage * self.scrollView.bounds.size.width;
[self.scrollView setContentOffset:CGPointMake(x, 0) animated:YES];
}
- (void)viewDidLoad
{
[super viewDidLoad];
//设置图片
for (int i = 0; i<kImageCount; i++) {
NSString *imageName = [NSString stringWithFormat:@"img_%02d", i+1 ];
UIImage *image = [UIImage imageNamed:imageName];
UIImageView *imageView = [[UIImageView alloc] initWithFrame: self.scrollView.bounds];
imageView.image = image;
[self.scrollView addSubview:imageView];
}
//计算imageView的位置
[self.scrollView.subviews enumerateObjectsUsingBlock:^(UIImageView *imageView, NSUInteger idx, BOOL *stop) {
//调整x =》 origin =》frame
CGRect frame = imageView.frame;
frame.origin.x = idx * frame.size.width;
imageView.frame = frame;
}];
//分页初始页数为0
self.pageControl.currentPage = 0;
//启动时钟
[self startTimer];
}
/**启动时钟*/
-(void)startTimer
{
self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES];
//添加运行循环
[[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];
}
-(void)updateTimer
{
//页号发生变化
//(当前页数 + 1) % 总页数
int page = (self.pageControl.currentPage+1) % kImageCount;
self.pageControl.currentPage = page;
//调用监听方法。让滚动视图滚动
[self pageChanged:self.pageControl];
}
#pragma mark - scrollView的代理方法
//滚动视图停下来
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
// 停下来的当前页数,通过contentOffset获取当前偏移量
NSLog(@"%@",NSStringFromCGPoint(scrollView.contentOffset));
//计算页数
int page = scrollView.contentOffset.x/scrollView.bounds.size.width;
self.pageControl.currentPage = page;
}
/**
抓住图片时,停止时钟,松手后,开启时钟
*/
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
//停止时钟,停止后就不能在使用,如果要启用时钟,需要重新实例化
[self.timer invalidate];
}
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
//启动时钟
[self startTimer];
}
@end
实现思路
1.scrollView getter方法懒加载
指定了大小,添加到视图
2,viewDidLoad中添加图像,并计算位置
3,运行观察效果,修改scrollView的属性….
4,实例化UIPageControl
5,因为分页控件与滚动视图分离,因此监听滚动停止代理方法,修改分页控件的页数
6,将UIPageControl定义成属性,并且添加监听方法。
7,实现监听方法,页数变化后,修改scrollView的位置
8,添加时钟,调用分页控件的监听方法,实现图片自动轮播
ps:新建iOS交流学习群:304570962
可以加猫猫QQ:1764541256 或则微信znycat
让我们一起努力学习吧。
原文:http://blog.csdn.net/u013357243?viewmode=contents