UIScrollView, 滚动视图
UIScrollView, 滚动视图
UIScrollView, 滚动视图, 继承于UIView, 用于显示超过一个屏幕的内容
frame: 是滚动视图可视区域的大小
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; scrollView.backgroundColor = [UIColor colorWithRed:0.586 green:1.000 blue:0.977 alpha:1.000];
内容页的大小, 默认值:CGSizeZero
contentSize.width > frame.width: 水平滚动
contentSize.height > frame.height: 垂直滚动
scrollView.contentSize = CGSizeMake(375 * 2, 667 * 2);
是否能滚动到顶部(点击状态栏触发), 默认是YES
scrollView.scrollsToTop = YES;
内容页的偏移量
scrollView.contentOffset = CGPointMake(0, 0);
[scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
是否可以滚动, 默认YES
scrollView.scrollEnabled = YES;
是否显示垂直滚动条, 默认是YES
scrollView.showsVerticalScrollIndicator = YES;
是否显示水平滚动条, 默认是YES
scrollView.showsHorizontalScrollIndicator = YES;
是否回弹(前提: 能够滚动), 默认YES
scrollView.bounces = YES;
是否回弹(前提: 不能滚动, bounces是YES), 默认NO
scrollView.alwaysBounceVertical = YES;
scrollView.alwaysBounceHorizontal = YES;
是否整屏滚动, 默认是NO
scrollView.pagingEnabled = NO;
代理
scrollView.delegate = self;
scrollView.tag = 1024;
[self.view addSubview:scrollView];
[scrollView release];
UIImageView如果不设置frame, frame大小 = 图片大小
imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Baymax.jpg"]];
只有添加到scrollView上, 视图才能跟着scrollView一起滚动
[scrollView addSubview:imageView];
[imageView release];
滚动视图上的内容缩放
1.设置delegate
2.修改scrollView属性
当前的缩放比例, 默认值1.0 scrollView.zoomScale = 1.0; 最大缩放比例, 默认为1.0 scrollView.maximumZoomScale = 4.0; 最小缩放比例, 默认为1.0 scrollView.minimumZoomScale = 0.5;
3.指定缩放的视图
UIPageControl, 页面控件, 继承于UIControl, 一般配合UIScrollView使用
注: UIPageControl适用于页数比较少的情况, 比如5页以内; 如果页数比较多, 可以使用UILabel直接显示"第99页"
UIPageControl *pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(100, 600, 175, 40)];
pageControl.backgroundColor = [UIColor blackColor];
设置页数, 默认为0
pageControl.numberOfPages = 5;
当前页数, 默认为0
pageControl.currentPage = 1;
未选中圆点颜色
pageControl.pageIndicatorTintColor = [UIColor redColor];
选中圆点颜色
pageControl.currentPageIndicatorTintColor = [UIColor greenColor];
当只有一页时, 是否隐藏
pageControl.hidesForSinglePage = YES;
[pageControl addTarget:self action:@selector(changePage:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:pageControl];
[pageControl release];
UIButton *nextButton = [UIButton buttonWithType:UIButtonTypeSystem];
nextButton.frame = CGRectMake(375 - 100, 40, 80, 30);
[nextButton setTitle:@"下 一 页" forState:UIControlStateNormal];
[nextButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[nextButton addTarget:self action:@selector(nextPage) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:nextButton];
UIButton *reset = [UIButton buttonWithType:UIButtonTypeSystem];
reset.frame = CGRectMake(20, 40, 80, 30);
[reset setTitle:@"还 原" forState:UIControlStateNormal];
[reset setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[reset addTarget:self action:@selector(reset) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:reset];
- (void)nextPage {
UIScrollView *scrollView = (UIScrollView *)[self.view viewWithTag:1024];
改变偏移量
// scrollView.contentOffset = CGPointMake(375, 0);
[scrollView setContentOffset:CGPointMake(375, 0) animated:YES];
}
- (void)reset {
UIScrollView *scrollView = (UIScrollView *)[self.view viewWithTag:1024];
重置scrollView的缩放比例
// scrollView.zoomScale = 1.0;
[scrollView setZoomScale:1.0 animated:YES];
}
#pragma mark - UIScrollViewDelegate
//当滚动视图的偏移量做改变, 执行这个方法
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
NSLog(@"已经滚动");
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
NSLog(@"将要开始拖拽");
}
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
//inout: 方法 内部使用的变量 和 外部使用的变量 是同一个
NSLog(@"将要结束拖拽");
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
NSLog(@"已经结束拖拽");
}
- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {
NSLog(@"将要开始减速");
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
NSLog(@"已经结束减速");
}
//调用setContentOffset:animated:这个方法触发
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
NSLog(@"已经结束滚动动画");
}
- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView {
return YES;
}
- (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView {
NSLog(@"已经滚动到顶部");
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
//指定缩放的视图
return imageView;
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
NSLog(@"滚动视图已经缩放");
}
- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view {
NSLog(@"滚动视图将要开始缩放");
}
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale {
NSLog(@"滚动视图已经结束缩放");
}
#import "WelcomeViewController.h" @interface WelcomeViewController () <UIScrollViewDelegate> { UIScrollView *bgScrollView; UIPageControl *pagecontrol; } @end @implementation WelcomeViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. //创建滚动视图 bgScrollView = [[UIScrollView alloc] initWithFrame:self.view.frame]; bgScrollView.backgroundColor = [UIColor colorWithRed:0.966 green:1.000 blue:0.429 alpha:1.000]; bgScrollView.contentSize = CGSizeMake(320 * 4, 568); bgScrollView.pagingEnabled = YES; bgScrollView.showsHorizontalScrollIndicator = NO; bgScrollView.tag = 101; bgScrollView.delegate = self; [self.view addSubview:bgScrollView]; [bgScrollView release]; for (NSInteger i = 1; i <= 4 ; i++) { NSString *name = [NSString stringWithFormat:@"%ld.jpg", i]; UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:name]]; imageView.frame = CGRectMake(320 * (i - 1), 0, 320, 568); [bgScrollView addSubview:imageView]; } pagecontrol = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 528, 320, 40)]; // pagecontrol.backgroundColor = [UIColor yellowColor]; pagecontrol.numberOfPages = 4; pagecontrol.pageIndicatorTintColor = [UIColor grayColor]; pagecontrol.currentPageIndicatorTintColor = [UIColor greenColor]; [pagecontrol addTarget:self action:@selector(changePage:) forControlEvents:UIControlEventValueChanged]; [self.view addSubview:pagecontrol]; [pagecontrol release]; } - (void)changePage:(UIPageControl *)pageControl { bgScrollView.contentOffset = CGPointMake(320 * pageControl.currentPage, 0); } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } #pragma mark - UIScrollViewDelegate - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { pagecontrol.currentPage = scrollView.contentOffset.x / 320; NSLog(@"%.2lf", scrollView.contentOffset.x / 320); } @end
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