ScrollView实现自动轮播

import "ViewController.h"

@interface ViewController ()<UIScrollViewDelegate>

{
NSTimer *_timer;
BOOL isAdd;
}

@property (nonatomic, strong) UIScrollView *scrollView;
@property (nonatomic, strong) NSMutableArray *advsList;
@property (nonatomic, strong) UIPageControl *pagePoint;

@end

/**

屏幕宽度
*/

define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)

/**

屏幕高度
*/

define SCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)

@implementation ViewController

(void)viewDidLoad {
[super viewDidLoad];

[self addView];
[self showAdvs];
[self addNSTimer];

}

pragma mark -创建图片数组

(NSMutableArray *)advsList
{
if(_advsList == nil){
_advsList = [NSMutableArray array];
}
return _advsList;
}

pragma mark -添加控件

(void)addView{

//添加图片
for (int i = 1; i < 5; i++) {
[self.advsList addObject:[NSString stringWithFormat:@"%d",i]];
}
self.view.backgroundColor = [UIColor whiteColor];

//添加滑动视图
self.scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 100, self.view.frame.size.width, 150)];
//设置代理这个必须的
self.scrollView.delegate = self;
//设置总大小也就是里面容纳的大小
self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width * self.advsList.count,self.scrollView.frame.size.height);
[self.scrollView setBackgroundColor:[UIColor blackColor]];
//里面的子视图跟随父视图改变大小
[self.scrollView setAutoresizesSubviews:YES];
//设置分页形式，这个必须设置
[self.scrollView setPagingEnabled:YES];
//隐藏横竖滑动块
[self.scrollView setShowsVerticalScrollIndicator:NO];
[self.scrollView setShowsHorizontalScrollIndicator:NO];
[self.view addSubview:self.scrollView];
//场景UIPageControl显示控件，并修改小点颜色
self.pagePoint = [[UIPageControl alloc]init];
self.pagePoint.currentPageIndicatorTintColor = [UIColor blackColor];
self.pagePoint.pageIndicatorTintColor = [UIColor grayColor];
self.pagePoint.frame = CGRectMake(self.view.frame.size.width - self.pagePoint.bounds.size.width-self.advsList.count*10, self.scrollView.frame.origin.y+135, self.pagePoint.bounds.size.width, self.pagePoint.bounds.size.height);
[self.pagePoint setNumberOfPages:[self.advsList count]];
[self.view addSubview:self.pagePoint];

}

pragma mark -展示广告位,初始化

(void)showAdvs{

isAdd = true;
for (UIView *view in [self.scrollView subviews]){
[view removeFromSuperview];
}
for(int i = 0; i < [self.advsList count]; i ++){
UIButton *thumbView = [[UIButton alloc] init];
[thumbView addTarget:self
action:@selector(myDidSelectAdvAtIndex:)
forControlEvents:UIControlEventTouchUpInside];
thumbView.tag = i;
thumbView.frame = CGRectMake(self.view.frame.size.width * i, 0, self.view.frame.size.width, 150);
[thumbView setBackgroundImage:[UIImage imageNamed:self.advsList[i]] forState:UIControlStateNormal];
thumbView.adjustsImageWhenHighlighted = NO;
[self.scrollView addSubview:thumbView];
}
}

pragma mark -添加定时器

(void)addNSTimer
{
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
//添加到runloop中
[[NSRunLoop mainRunLoop]addTimer:timer forMode:NSRunLoopCommonModes];
_timer = timer;
}

pragma mark -删除定时器

(void)removeNSTimer
{
[ _timer invalidate];
_timer =nil;
}

pragma mark -定时器下一页

(void)nextPage{
NSInteger num = self.pagePoint.currentPage;
if(isAdd){
num++;
if(num == self.advsList.count -1){
isAdd = false;
}
}else{
num--;
if(num == 0){
isAdd = true;
}
}
[self scrollToIndex:num];
}

pragma mark -滑动的距离

(void)scrollToIndex:(NSInteger)index
{

CGRect frame = self.scrollView.frame;
frame.origin.x = frame.size.width * index;
frame.origin.y = 0;
[self.scrollView scrollRectToVisible:frame animated:YES];
}

pragma mark -滑动完成时计算滑动到第几页

(void)scrollViewDidScroll:(UIScrollView *)scrollView
{

CGFloat pageWidth = scrollView.frame.size.width;
int page = floor((scrollView.contentOffset.x - pageWidth / 2) /pageWidth) +1;
[self.pagePoint setCurrentPage:page];
}

pragma mark -当用户开始拖拽的时候就调用移除计时器

(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
[self removeNSTimer];
}

pragma mark -当用户停止拖拽的时候调用添加定时器

(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
[self addNSTimer];
}

pragma mark -点击广告

(void)myDidSelectAdvAtIndex:(id) index
{
UIButton *thumbView = (UIButton *)index;
NSLog(@"你点击了第个%ld广告",thumbView.tag);
}
(void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}