iOS轮播图的实现

   //使用轮播图展示一组图片信息

    //定时器  使循环

    [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(runTimePage) userInfo:nil repeats:YES];

    //初始化scrollview

    self.scrollview = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 64, 320, 200)];

    self.scrollview.bounces = YES;

    self.scrollview.pagingEnabled = YES;

    self.scrollview.delegate = self;

    self.scrollview.userInteractionEnabled = YES;

    self.scrollview.showsHorizontalScrollIndicator = NO;

    self.scrollview.showsVerticalScrollIndicator = NO;

    [self.homeView addSubview:self.scrollview];

    //初始化存放循环图片的数组

    self.slideImages = [NSMutableArray array];

    [self.slideImages addObject:@"1.jpg"];

    [self.slideImages addObject:@"2.jpg"];

    [self.slideImages addObject:@"3.jpg"];

    [self.slideImages addObject:@"4.jpg"];

    //初始化pageControl

    self.pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(110,240.0,100.0,18.0)]; // 初始化mypagecontrol

    [self.pageControl setCurrentPageIndicatorTintColor:[UIColor redColor]];

    [self.pageControl setPageIndicatorTintColor:[UIColor blackColor]];

    self.pageControl.numberOfPages = [self.slideImages count];

    self.pageControl.currentPage = 0;

    [self.pageControl addTarget:self action:@selector(turnPage) forControlEvents:UIControlEventValueChanged]; // 触摸mypagecontrol触发change这个方法事件

    [self.homeView addSubview:self.pageControl];

    // 创建四个图片 imageviewm,

    for (int i = 0;i<[self.slideImages count];i++)

    {

        UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[self.slideImages objectAtIndex:i]]];

        imageView.frame = CGRectMake((320 * i) + 320, 0, 320, 190.0);

        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(didClickTapGesture:)];

        imageView.tag = i + 100;

        imageView.userInteractionEnabled = YES;

        [imageView addGestureRecognizer:tapGesture];

        [self.scrollview addSubview:imageView]; // 首页是第0页,默认从第1页开始的。所以+320。。。

    }

    // 取数组最后一张图片 放在第0页

    UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[self.slideImages objectAtIndex:([self.slideImages count]-1)]]];

    imageView.frame = CGRectMake(0, 0, 320, 190.0); // 添加最后1页在首页 循环

    [self.scrollview addSubview:imageView];

    // 取数组第一张图片 放在最后1页

    imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[self.slideImages objectAtIndex:0]]];

    imageView.frame = CGRectMake((320 * ([self.slideImages count] + 1)) , 0, 320, 190.0); // 添加第1页在最后 循环

    [self.scrollview addSubview:imageView];

    [self.scrollview setContentSize:CGSizeMake(320 * ([self.slideImages count] + 2), 190.0

                                               )]; //  +上第1页和第4页  原理：4-[1-2-3-4]-1

    [self.scrollview setContentOffset:CGPointMake(0, 0)];

    [self.scrollview scrollRectToVisible:CGRectMake(320,64,320,190.0) animated:NO]; // 默认从序号1位置放第1页 ，序号0位置位置放第4页

#pragma -------------------------------轮播图-----------------------------------------

// scrollview 委托函数

- (void)scrollViewDidScroll:(UIScrollView *)sender

{

    CGFloat pagewidth = self.scrollview.frame.size.width;

    int page = floor((self.scrollview.contentOffset.x - pagewidth/([self.slideImages count]+2))/pagewidth)+1;

    page --;  // 默认从第二页开始

    self.pageControl.currentPage = page;

}

// scrollview 委托函数

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

    CGFloat pagewidth = self.scrollview.frame.size.width;

    int currentPage = floor((self.scrollview.contentOffset.x - pagewidth/ ([self.slideImages count]+2)) / pagewidth) + 1;

    //    int currentPage_ = (int)self.scrollView.contentOffset.x/320; // 和上面两行效果一样

    //    NSLog(@"currentPage_==%d",currentPage_);

    if (currentPage==0)

    {

        [self.scrollview scrollRectToVisible:CGRectMake(320 * [self.slideImages count],64,320,190.0) animated:NO]; // 序号0 最后1页

    }

    else if (currentPage==([self.slideImages count]+1))

    {

        [self.scrollview scrollRectToVisible:CGRectMake(320,0,320,190.0) animated:NO]; // 最后+1,循环第1页

    }

}

// pagecontrol 选择器的方法

- (void)turnPage

{

    int page = self.pageControl.currentPage; // 获取当前的page

    [self.scrollview scrollRectToVisible:CGRectMake(320*(page+1),0,320,190.0) animated:NO]; // 触摸pagecontroller那个点点 往后翻一页 +1

}

// 定时器 绑定的方法

- (void)runTimePage

{

    int page = self.pageControl.currentPage; // 获取当前的page

    page++;

    page = page > 3 ? 0 : page ;

    self.pageControl.currentPage = page;

    [self turnPage];

}

//图片手势

- (void)didClickTapGesture:(UITapGestureRecognizer *)gesture

{

        UIImageView * imageView = nil;

        switch (gesture.view.tag) {

            case 101:

                imageView = (UIImageView *)[self.scrollview viewWithTag:101];

                break;

            case 102:

                imageView = (UIImageView *)[self.scrollview viewWithTag:102];

                 break;

            case 103:

                imageView = (UIImageView *)[self.scrollview viewWithTag:103];

                 break;

            default:

                break;

        }

}