自动小轮播图

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//封装UIScrollView 方法

- (void)initscroll{

//初始化

self.scrollview = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 20, CGRectGetWidth(self.view.bounds), 220)];

//self.scrollview.backgroundColor = [UIColor redColor];

//添加到视图

[self.view addSubview:self.scrollview];

//设置滚动视图的长度

[self.scrollview setContentSize:CGSizeMake(CGRectGetWidth(self.view.bounds)*4, 0)];

for (NSInteger i = 0; i < 4; i++) {

UIImageView *imageview = [[UIImageView alloc]initWithFrame:CGRectMake(CGRectGetWidth(self.view.bounds)*i, 0, CGRectGetWidth(self.view.bounds), 220)];

// 设置图片

[imageview setImage:[UIImage imageNamed:[NSString stringWithFormat:@"%ld.jpg",(long)i]]];

[self.scrollview addSubview:imageview];

}

//设置图片的分页

[self.scrollview setPagingEnabled:YES];

//将图片水平面的横线隐藏

[self.scrollview setShowsHorizontalScrollIndicator:NO];

self.scrollview.delegate = self;

//设置滚动视图下面的点

self.pagecon = [[UIPageControl alloc]initWithFrame:CGRectMake(0, CGRectGetMaxY(self.scrollview.frame)-20, self.view.frame.size.width, 20)];

//设置的点数

[self.pagecon setNumberOfPages:4];

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

[self.view addSubview:self.pagecon];

self.edgesForExtendedLayout = UIRectEdgeNone;

self.automaticallyAdjustsScrollViewInsets = YES;

}

//调用 UIscrollview 的协议方法

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

[self.pagecon setCurrentPage:(NSInteger)(scrollView.contentOffset.x / CGRectGetWidth(scrollView.frame))];

}

//封装的定时器

- (void)initTimer{

if (!self.timer) {

self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(click) userInfo:nil repeats:YES];

//定时器会跑在标记为common modes的模式下，以上两种通用，像广告轮播等就会用到该模式。

[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];

/*self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(click) userInfo:nil repeats:YES];

[[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];

*/

}

}

-(void)click{

NSInteger pagecount = self.pagecon.currentPage + 1;

if (pagecount >= 4) {

pagecount = 0;

}

[self.scrollview setContentOffset:CGPointMake(pagecount * CGRectGetWidth(self.scrollview.frame), 0) animated:YES];

}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{

if (self.timer) {

//invalidate 废弃

[self.timer invalidate];

[self setTimer:nil];

}

}

//结束后返回第一张图片

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

[self initTimer];

}