效果：
//
// RootViewController.m
// 头部滚动展示视图
//
// Created by 寒竹子 on 15/4/1.
// Copyright (c) 2015年 摩天居士. All rights reserved.
// 头部滚动广告视图
#define SCREEN_SIZE [UIScreen mainScreen].bounds.size
#define KImageCnt 5
#define KImage_H 250
#import "RootViewController.h"
@interface RootViewController ()<UIScrollViewDelegate>
@property (nonatomic, strong) UIScrollView * scrollView;
@property (nonatomic, strong) UIPageControl * pageControl;
@property (nonatomic, strong) NSTimer * timer;
@end
@implementation RootViewController
/**
* scrollView
*/
- (UIScrollView *)scrollView
{
if (_scrollView == nil) {
_scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_SIZE.width, KImage_H)];
_scrollView.pagingEnabled = YES;
_scrollView.showsHorizontalScrollIndicator = NO;
}
return _scrollView;
}
/**
* PageControl
*/
- (UIPageControl *)pageControl
{
if (_pageControl == nil) {
_pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, self.scrollView.frame.size.height - 30, SCREEN_SIZE.width, 20)];
_pageControl.currentPageIndicatorTintColor = [UIColor colorWithRed:65 / 255.0 green:168 / 255.0 blue:100/255.0 alpha:1.0];
_pageControl.pageIndicatorTintColor = [UIColor grayColor];
}
return _pageControl;
}
/**
* 初始化UI
*/
- (void)setupUI
{
[self.view addSubview:self.scrollView];
[self.view addSubview:self.pageControl];
CGFloat imageY = 0;
CGFloat imageW = SCREEN_SIZE.width;
CGFloat imageH = KImage_H;
for (int i = 0; i < KImageCnt; i++) {
UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(i * imageW, imageY, imageW, imageH)];
imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"image_%i.jpg", i+1]];
[self.scrollView addSubview:imageView];
}
// 设置scrollView属性
self.scrollView.contentSize = CGSizeMake(KImageCnt * imageW, 0);
self.scrollView.delegate = self;
self.pageControl.numberOfPages = KImageCnt;
// 设置自动播放
[self turnOnTimer];
}
/**
* 打开定时器
*/
- (void)turnOnTimer
{
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(playImage) userInfo:nil repeats:YES];
// 为了防止单线程弊端
[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}
/**
* 关闭定时器
*/
- (void)turnOffTimer
{
[self.timer invalidate];
self.timer = nil;
}
/**
* 自动播放图片
*/
- (void)playImage
{
int i = self.pageControl.currentPage;
if (i == KImageCnt - 1) {
i = -1;
}
i++;
[self.scrollView setContentOffset:CGPointMake(i * self.scrollView.frame.size.width, 0) animated:YES];
}
- (void)viewDidLoad {
[super viewDidLoad];
[self setupUI];
}
#pragma mark - UIScrollViewDelegate
/**
* 用户准备拖拽的时候关闭定时器
*/
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
[self turnOffTimer];
}
/**
* 用户停止拖拽的时候新开启一个定时器
*/
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
[self turnOnTimer];
}
// 判断定时器滚动的时候 判断滚动的位置 以让pageControl显示当前的page
// 在总宽度上加上半个scrollView的宽度 是为了实现拖动到一半时左右的效果
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
self.pageControl.currentPage = (self.scrollView.frame.size.width * 0.5 + self.scrollView.contentOffset.x) / self.scrollView.frame.size.width;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end