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

[objc] view
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@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

在程序中导入图片，在.m文件中的代码实现：

[objc] view
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- (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];

}