轮播图片——APP顶上头条

来源：互联网发布：陕西师范网络教育编辑：程序博客网时间：2024/04/28 20:45

#import "ViewController.h"

#define imageCount 5

@interface ViewController ()<UIScrollViewDelegate>

@property (nonatomic,strong)UIScrollView *scrollView;

@property (nonatomic,strong)UIPageControl *pageControl;

@property (nonatomic,strong)NSTimer *timer;

@end

@implementation ViewController

-(UIScrollView *)scrollView

{

if (_scrollView ==nil) {

_scrollView = [[UIScrollViewalloc]initWithFrame:CGRectMake(10,20, 300, 130)];

_scrollView.backgroundColor = [UIColorredColor];

[self.viewaddSubview:_scrollView];

// 要分页

_scrollView.pagingEnabled =YES;

// contentSize 在_scrollView设置可以滚动的局域

_scrollView.contentSize =CGSizeMake(imageCount *_scrollView.bounds.size.width,0);

// 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 = [[UIPageControlalloc] init];

// 总页数

_pageControl.numberOfPages =imageCount;

// 控件尺寸

//CGSize size = [_pageControl sizeForNumberOfPages:imageCount];

// _pageControl.bounds = CGRectMake(0, 0, size.width, size.height);

_pageControl.center =CGPointMake(self.view.center.x,130);

// 设置颜色

_pageControl.pageIndicatorTintColor = [UIColorredColor];

_pageControl.currentPageIndicatorTintColor = [UIColorblueColor];

[self.viewaddSubview:_pageControl];

// 添加监听方法

/** 在OC中，绝大多数"控件"，都可以监听UIControlEventValueChanged事件，button除外" */

[_pageControladdTarget:selfaction:@selector(pagechanged:)forControlEvents:UIControlEventValueChanged];

}

return_pageControl;

}

// 分页控件的监听方法

-(void)pagechanged:(UIPageControl *)page

{

// 根据页数，调整滚动视图中的图片位置 contentOffset

CGFloat x = page.currentPage *self.scrollView.bounds.size.width;

[self.scrollViewsetContentOffset:CGPointMake(x,0) animated:YES];

}

// 视图加载完成调用，通常用来设置数据

- (void)viewDidLoad {

[superviewDidLoad];

[selfscrollView];

// 设置图片

for (int i =0; i < imageCount; i++) {

NSString *imageName = [NSStringstringWithFormat:@"img_%02d",i +1];

UIImage *imge = [UIImageimageNamed:imageName];

UIImageView *imageView = [[UIImageViewalloc] initWithFrame:self.scrollView.bounds];

imageView.image = imge;

[self.scrollViewaddSubview:imageView];

}

// 计算imageView的位置

[self.scrollView.subviewsenumerateObjectsUsingBlock:^(UIImageView *imageView,NSUInteger idx, BOOL *stop) {

CGRect frame = imageView.frame;

frame.origin.x = idx * frame.size.width;

imageView.frame = frame;

NSLog(@"%@",self.scrollView.subviews);

}];

// 分页初始页数为0

self.pageControl.currentPage =0;

// 启动时钟

[selfstartTime];

}

-(void)startTime

{

self.timer = [NSTimertimerWithTimeInterval:2.5target:selfselector:@selector(updateTimer)userInfo:nilrepeats:YES];

// 添加到运行循环

[[NSRunLoopcurrentRunLoop]addTimer:self.timerforMode:NSRunLoopCommonModes];

}

-(void )updateTimer

{

// 页号发生变化

// (当前的页数 + 1) %总页数

int page = (self.pageControl.currentPage +1) % imageCount;

self.pageControl.currentPage = page;

//调用监听方法，让滚动视图滚动

[selfpagechanged:self.pageControl];

}

#pragma mark - ScrollView的代理方法

// 滚动视图停下来，修改页面控件的小点（页数）

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

NSLog(@"%@",NSStringFromCGPoint(scrollView.contentOffset));

int page = scrollView.contentOffset.x /scrollView.bounds.size.width;

self.pageControl.currentPage = page;

}

-(void) scrollViewWillBeginDragging:(UIScrollView *)scrollView

{

[self.timerinvalidate];

}

-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

{

[selfstartTime];

}

@end

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