iOS学习笔记——滚动视图（scrollView）

@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

- (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];
//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];
}