ios 圖片自動輪播

標籤：

#import "NYViewController.h"#define kImageCount 5@interface NYViewController () <UIScrollViewDelegate>@property (nonatomic, strong) UIScrollView *scrollView;@property (nonatomic, strong) UIPageControl *pageControl;@property (nonatomic, strong) NSTimer *timer;@end@implementation NYViewController//懶載入載入scrollView-(UIScrollView *)scrollView{    if (_scrollView == nil) {        _scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 20, 300, 130)];        _scrollView.backgroundColor = [UIColor redColor];        [self.view addSubview:_scrollView];        //contentSize        //高度為0 只水平滾動        self.scrollView.contentSize = CGSizeMake(kImageCount * _scrollView.bounds.size.width, 0);        //取消彈簧效果        _scrollView.bounces = NO;        //取消捲軸        _scrollView.showsHorizontalScrollIndicator = NO;//水平        _scrollView.showsVerticalScrollIndicator = NO;//豎直        //要分頁        _scrollView.pagingEnabled = YES;        //設定代理        _scrollView.delegate = self;    }    return _scrollView;}-(UIPageControl *)pageControl{    if (_pageControl == nil) {        //分頁控制項，本質上和scrollView沒有任何關係，是兩個獨立的控制項        _pageControl = [[UIPageControl alloc]init];        //總頁數        _pageControl.numberOfPages = kImageCount;        //控制項尺寸        CGSize size = [_pageControl sizeForNumberOfPages:kImageCount];        _pageControl.bounds = CGRectMake(0, 0, size.width, size.height);        _pageControl.center = CGPointMake(self.view.center.x, 130);        //設定顏色        _pageControl.pageIndicatorTintColor = [UIColor redColor];        _pageControl.currentPageIndicatorTintColor = [UIColor blackColor];        [self.view addSubview:_pageControl];        //添加監聽方法        /**在OC中，絕大多數“繼承UIControl控制項”，都可以監聽UIControlEventValueChanged事件，只有button除外，button是點得，是touchup。。。*/        [_pageControl addTarget:self action:@selector(pageChanged:) forControlEvents:UIControlEventValueChanged];    }    return _pageControl;}//分頁控制項的監聽方法-(void)pageChanged:(UIPageControl *)page{    //根據頁數，調整滾動視圖中得圖片位置contentOffset    CGFloat x = page.currentPage * self.scrollView.bounds.size.width;    [self.scrollView setContentOffset:CGPointMake(x, 0) animated:YES];}- (void)viewDidLoad{    [super viewDidLoad];    //設定圖片    for (int i = 0; i<kImageCount; i++) {        NSString *imageName = [NSString stringWithFormat:@"img_%02d", i+1 ];        UIImage *image = [UIImage imageNamed:imageName];        UIImageView *imageView = [[UIImageView alloc] initWithFrame: self.scrollView.bounds];        imageView.image = image;        [self.scrollView addSubview:imageView];    }    //計算imageView的位置    [self.scrollView.subviews enumerateObjectsUsingBlock:^(UIImageView *imageView, NSUInteger idx, BOOL *stop) {        //調整x =》 origin =》frame        CGRect frame = imageView.frame;        frame.origin.x = idx * frame.size.width;        imageView.frame = frame;    }];    //分頁初始頁數為0    self.pageControl.currentPage = 0;    //啟動時鐘    [self startTimer];}/**啟動時鐘*/-(void)startTimer{    self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES];    //添加運行迴圈    [[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];}-(void)updateTimer{    //頁號發生變化    //（當前頁數 + 1） % 總頁數    int page = (self.pageControl.currentPage+1) % kImageCount;    self.pageControl.currentPage = page;    //調用監聽方法。讓滾動視圖滾動    [self pageChanged:self.pageControl];}#pragma mark - scrollView的代理方法//滾動視圖停下來-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{    // 停下來的當前頁數,通過contentOffset擷取當前位移量    NSLog(@"%@",NSStringFromCGPoint(scrollView.contentOffset));    //計算頁數    int page = scrollView.contentOffset.x/scrollView.bounds.size.width;    self.pageControl.currentPage = page;}/** 抓住圖片時，停止時鐘，鬆手後，開啟時鐘 */-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{    //停止時鐘，停止後就不能在使用，如果要啟用時鐘，需要重新執行個體化    [self.timer invalidate];}-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{    //啟動時鐘    [self startTimer];}@end

 

ios 圖片自動輪播