iOS 轮播图

来源：互联网发布：网络推广学什么编辑：程序博客网时间：2024/05/27 09:48
一提到轮播图，我们很多人会用scrollView进行处理，我们可以利用contentoffsize属性对显示窗口进行设置。
- (void)viewDidLoad {    [super viewDidLoad];    scrollViewDemo=[[UIScrollView alloc]initWithFrame:CGRectMake(0,0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height/2)];    scrollViewDemo.backgroundColor=[UIColor whiteColor];    [self.view addSubview:scrollViewDemo];    pageControl=[[UIPageControl alloc]initWithFrame:CGRectMake(([UIScreen mainScreen].bounds.size.width-200)/2, scrollViewDemo.frame.size.height-60, 200, 60)];//  图片的个数    count=4;    dataSource=@[@"demo1",@"demo2",@"demo3",@"demo4"];//    获得scrollView的宽度    CGFloat width=scrollViewDemo.frame.size.width;    //添加图片到ScrollView    for (int i=0; i<dataSource.count; i++) {        UIImageView *imageView=[[UIImageView alloc]initWithFrame:CGRectMake(i*width, 0, width, scrollViewDemo.frame.size.height)];        imageView.image=[UIImage imageNamed:dataSource                         [i]];        [scrollViewDemo addSubview:imageView];    }    scrollViewDemo.contentSize=CGSizeMake(count*width, 0);    //图片的个数，指示器的颜色    pageControl.numberOfPages=count;    pageControl.pageIndicatorTintColor=[UIColor whiteColor];    pageControl.currentPageIndicatorTintColor=[UIColor blueColor];    //分页的格式，水平滚动条    scrollViewDemo.pagingEnabled=YES;    scrollViewDemo.showsHorizontalScrollIndicator=NO;    scrollViewDemo.delegate=self;    [self.view addSubview:pageControl];    //定时轮播图片    [self startTimer];}//启动定时器-(void)startTimer{    timer=[NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(nextImage) userInfo:nil repeats:YES];    [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];}//接下来要显示的图片-(void)nextImage{    int page=0;    if (pageControl.currentPage==count-1) {        page =0;        pageControl.currentPage=0;    }else{        pageControl.currentPage++;        page=(int)pageControl.currentPage;    }    CGFloat offWidth=(page)*scrollViewDemo.frame.size.width;    [scrollViewDemo setContentOffset:CGPointMake(offWidth, -64)];}-(void)viewWillDisappear:(BOOL)animated{    [timer invalidate];}#pragma mark-UIScrollViewDelegate//滑动的时候对应的修改pagecontrol-(void)scrollViewDidScroll:(UIScrollView *)scrollView{    CGFloat width=scrollView.frame.size.width;    float page=(scrollView.contentOffset.x+width*0.5)/width;    if (scrollView.contentOffset.x>width*3.1) {        pageControl.currentPage=0;        [UIView setAnimationDuration:0.3];        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];        scrollView.contentOffset=CGPointMake(0, -64);    }    if (scrollView.contentOffset.x<-width*0.1) {        pageControl.currentPage=3;        [UIView setAnimationDuration:0.3];        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];        scrollView.contentOffset=CGPointMake(width*3, -64);    }    NSLog(@"scroll.x=%f",scrollView.contentOffset.x);    pageControl.currentPage=(int)page;    }//将开始滑动的时候，定时器关闭-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{    [timer invalidate];    timer=nil;}//滑动结束以后开始定时器-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{    [self startTimer];}@end
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