#import ViewController.h
#define ImageViewCount 5
@interface ViewController ()<uiscrollviewdelegate>
@property (weak, nonatomic) IBOutlet UIScrollView *imageScrollView;
@property (weak, nonatomic) IBOutlet UIPageControl *imageViewPageControl;
@property (strong, nonatomic) NSTimer *timer;
@end@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self addImageView2ScrollView];
self.imageScrollView.contentSize = CGSizeMake(self.imageScrollView.frame.size.width * ImageViewCount, 0);
self.imageScrollView.delegate = self;
self.imageScrollView.pagingEnabled = YES;//UIScrollView支持拖动分页
self.imageViewPageControl.numberOfPages = ImageViewCount;
[self addScrollTimer];
}- (void)rotatePic{
int currentPageIndex = self.imageViewPageControl.currentPage;
if(++currentPageIndex == 5){
currentPageIndex = 0;
}
CGFloat offsetX = currentPageIndex * self.imageScrollView.frame.size.width;
[UIView animateWithDuration:1 animations:^{
self.imageScrollView.contentOffset = CGPointMake(offsetX, 0);
}];
}/**添加图片到imageScrollView*/- (void)addImageView2ScrollView{
CGFloat imageWidth = self.imageScrollView.frame.size.width;
CGFloat imageHeight = self.imageScrollView.frame.size.height;
for(int i = 0;i <= ImageViewCount;i++){
UIImageView *imageInScroll = [[UIImageView alloc] init];
imageInScroll.frame = CGRectMake(i * imageWidth, 0, imageWidth, imageHeight);
imageInScroll.image = [UIImage imageNamed:[NSString stringWithFormat:@img_%02d,i + 1]];
[self.imageScrollView addSubview:imageInScroll];
}
}// 正滚动时执行- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
CGFloat offX = self.imageScrollView.contentOffset.x;//（0，0）距离content内部左上顶点的x轴长度
NSLog(@~~~~~~~%f ^^^^^^%f, offX, self.imageScrollView.frame.size.width);
int currentPageIndex = (offX + .5f * self.imageScrollView.frame.size.width) / self.imageScrollView.frame.size.width;
self.imageViewPageControl.currentPage = currentPageIndex;
}- (void)addScrollTimer{
self.timer = [NSTimer timerWithTimeInterval:2 target:self selector:@selector(rotatePic) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}- (void)removeScrollTimer{
[self.timer invalidate];//释放定时器
self.timer = nil;
}// 开始准备滚动时执行 移除定时滚动操作- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
NSLog(@~~~scrollViewWillBeginDragging);
[self removeScrollTimer];
}www.2cto.com// 结束滚动后执行 添加定时滚动操作- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
NSLog(@~~~scrollViewDidEndDragging);
[self addScrollTimer];
}@end</uiscrollviewdelegate> |
对UIScrollView的运用，以上代码中有详细注释，需注意2点：
1.注意设置contentSize属性。其中contentSize表示scroll内容尺寸大小
2.注意设置代理UIScrollViewDelegate，才可调用其中的方法
对于定时器NSTimer的运用需注意
1.在线程的loop中添加定时器
2.注意使用完成回收NSTimer
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