iOS学习笔记——滚动视图（scrollView）
滚动视图：在根视图中添加UIScrollViewDelegate协议，声明一些对象属性
@interface BoViewController : UIViewController<UIScrollViewDelegate> //滚动视图对象 @property (retain, nonatomic) UIScrollView *scrollView; //视图中小圆点，对应视图的页码 @property (retain, nonatomic) UIPageControl *pageControl; //动态数组对象，存储图片 @property (retain, nonatomic) NSMutableArray *images; @end /* 何问起 hovertree.com */
在程序中导入图片，在.m文件中的代码实现：
- (void)viewDidLoad { [super viewDidLoad]; //初始化scrollView self.scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, 320, 345)]; //初始化pageControl self.pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(0, 344, 320, 36)]; //初始化数组，存储滚动视图的图片 self.images = [NSMutableArray arrayWithObjects:[UIImage imageNamed:@"text1.png"],[UIImage imageNamed:@"text2.png"],[UIImage imageNamed:@"text3.png"],[UIImage imageNamed:@"text4.png"], nil nil]; //把scrollView与pageControl添加到当前视图中 [self.view addSubview:self.scrollView]; [self.view addSubview:self.pageControl]; //设置视图的背景颜色 self.view.backgroundColor = [UIColor blackColor]; //调用 setuoPage方法 [self setupPage:nil]; } //改变滚动视图的方法实现 - (void)setupPage:(id)sender { //设置委托 self.scrollView.delegate = self; //设置背景颜色 self.scrollView.backgroundColor = [UIColor blackColor]; //设置取消触摸 self.scrollView.canCancelContentTouches = NO; //设置滚动条类型 self.scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite; //是否自动裁切超出部分 self.scrollView.clipsToBounds = YES; //设置是否可以缩放 self.scrollView.scrollEnabled = YES; //设置是否可以进行画面切换 self.scrollView.pagingEnabled = YES; //设置在拖拽的时候是否锁定其在水平或者垂直的方向 self.scrollView.directionalLockEnabled = NO; //隐藏滚动条设置（水平、跟垂直方向） self.scrollView.alwaysBounceHorizontal = NO; self.scrollView.alwaysBounceVertical = NO; self.scrollView.showsHorizontalScrollIndicator = NO; self.scrollView.showsVerticalScrollIndicator = NO; //用来记录页数 NSUInteger pages = 0; //用来记录scrollView的x坐标 int originX = 0; for(UIImage *image in self.images) { //创建一个视图 UIImageView *pImageView = [[[UIImageView alloc]initWithFrame:CGRectZero]autorelease]; //设置视图的背景色 pImageView.backgroundColor = [UIColor colorWithRed:0.6 green:0.6 blue:0.6 alpha:1.0]; //设置imageView的背景图 [pImageView setImage:image]; //给imageView设置区域 CGRect rect = self.scrollView.frame; rect.origin.x = originX; rect.origin.y = 0; rect.size.width = self.scrollView.frame.size.width; rect.size.height = self.scrollView.frame.size.height; pImageView.frame = rect; //设置图片内容的显示模式(自适应模式) pImageView.contentMode = UIViewContentModeScaleAspectFill; //把视图添加到当前的滚动视图中 [self.scrollView addSubview:pImageView]; //下一张视图的x坐标:offset为:self.scrollView.frame.size.width. originX += self.scrollView.frame.size.width; //记录scrollView内imageView的个数 pages++; } //设置页码控制器的响应方法 [self.pageControl addTarget:self action:@selector(changePage:) forControlEvents:UIControlEventValueChanged]; //设置总页数 self.pageControl.numberOfPages = pages; //默认当前页为第一页 self.pageControl.currentPage = 0; //为页码控制器设置标签 self.pageControl.tag = 110; //设置滚动视图的位置 [self.scrollView setContentSize:CGSizeMake(originX, self.scrollView.bounds.size.height)]; } //改变页码的方法实现 - (void)changePage:(id)sender { NSLog(@"指示器的当前索引值为:%i",self.pageControl.currentPage); //获取当前视图的页码 CGRect rect = self.scrollView.frame; //设置视图的横坐标，一幅图为320*460，横坐标一次增加或减少320像素 rect.origin.x = self.pageControl.currentPage * self.scrollView.frame.size.width; //设置视图纵坐标为0 rect.origin.y = 0; //scrollView可视区域 [self.scrollView scrollRectToVisible:rect animated:YES]; } #pragma mark-----UIScrollViewDelegate--------- //实现协议UIScrollViewDelegate的方法，必须实现的 - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { //获取当前视图的宽度 CGFloat pageWith = scrollView.frame.size.width; //根据scrolView的左右滑动,对pageCotrol的当前指示器进行切换(设置currentPage) int page = floor((scrollView.contentOffset.x - pageWith/2)/pageWith)+1; //切换改变页码，小圆点 self.pageControl.currentPage = page; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } //释放创建的对象 - (void)dealloc { [_pageControl release]; [_scrollView release]; [super dealloc]; } /* 何问起 hovertree.com */
