iOS学习笔记——滚动视图（scrollView）

原始地址：http://blog.csdn.net/u012889435/article/details/17523705

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
 //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

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];
 }