iOS基础篇（十五）——UIScrollView的基本用法

 1 //初始化，设置尺寸和大小
 2     scrollView = [[UIScrollView alloc] initWithFrame:(CGRect){0,0,frame.size.width,frame.size.height}];
 3 //添加到视图
 4     [self.view addSubview:scrollView];
 5 //背景颜色
 6      scrollView.backgroundColor = [UIColor orangeColor];
 7 //滚动范围
 8     scrollView.contentSize = CGSizeMake(frame.size.width+100, frame.size.height+200);
 9 //设置代理
10     scrollView.delegate = self;
11 //是否分页
12     scrollView.pagingEnabled = YES;
13 //是否滚动
14     scrollView.scrollEnabled = YES;
15 //是否显示滚动条
16     scrollView.showsHorizontalScrollIndicator = YES;
17     scrollView.showsVerticalScrollIndicator = NO;
18 //滚动条风格
19     scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
20 //内容边缘和indicator边缘
21     scrollView.contentInset = UIEdgeInsetsMake(0, 20, 20, 20);
22     scrollView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 50, 0, 0);

 1     //初始化
 2     pageCtrl=[[UIPageControl alloc] initWithFrame:CGRectMake(0, 170, 375, 20)];
 3     [self.view addSubview:pageCtrl];
 4     //设置控制器页数（默认为0）
 5     pageCtrl.numberOfPages=3;
 6     //设置当前所在页码
 7     pageCtrl.currentPage = 1;
 8     //设置当总页数为1时，是否自动隐藏控制器
 9     pageCtrl.hidesForSinglePage = YES;
10     //设置控制器页码点得颜色
11     pageCtrl.pageIndicatorTintColor = [UIColor orangeColor];
12     //设置控制器当前所在页码点的颜色
13     pageCtrl.currentPageIndicatorTintColor = [UIColor greenColor];
14     pageCtrl.tag=100;
15     
16     //给pageControl添加点击事件
17     [pageCtrl addTarget:self action:@selector(turnPage:) forControlEvents:UIControlEventTouchUpInside];
18     

 1 @interface ViewController ()<UIScrollViewDelegate>{
 2     
 3     UIScrollView *scrollView;
 4     UIPageControl *pageCtrl;
 5     
 6     NSArray *imageArray;
 7 
 8 }
 9 
10 @end
11 
12 @implementation ViewController
13 
14 - (void)viewDidLoad {
15     [super viewDidLoad];
16     // Do any additional setup after loading the view, typically from a nib.
17     
18     //初始化
19     scrollView = [[UIScrollView alloc] initWithFrame:(CGRect){0,20,self.view.frame.size.width,self.view.frame.size.height}];
20     [self.view addSubview:scrollView];
21     //代理
22     scrollView.delegate = self;
23     //滑动范围
24     scrollView.contentSize = CGSizeMake(375*3, 180);
25     //背景颜色
26     scrollView.backgroundColor = [UIColor clearColor];
27     //是否分页
28     scrollView.pagingEnabled = YES;
29     //是否显示滚动条
30     scrollView.showsHorizontalScrollIndicator = NO;
31     scrollView.showsVerticalScrollIndicator = NO;
32     
33     //图片数组
34     imageArray = @[@"u=1522827729,398642494&fm=21&gp=0", @"u=498354980,1967037110&fm=21&gp=0", @"u=455056084,2054881807&fm=21&gp=0"];
35     
36     //加载图片
37     for (int i=0; i<3; i++) {
38         UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(i*375, 0, 375, 180)];
39         //imageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"image%d.jpg",i+1]];
40         NSString *image = [imageArray objectAtIndex:i];
41         imageView.image = [UIImage imageNamed:image];
42         
43         [scrollView addSubview:imageView];
44 
45     }
46     //初始化
47     pageCtrl=[[UIPageControl alloc] initWithFrame:CGRectMake(0, 170, 375, 20)];
48     [self.view addSubview:pageCtrl];
49     //设置控制器页数（默认为0）
50     pageCtrl.numberOfPages=3;
51     //设置当前所在页码
52     pageCtrl.currentPage = 1;
53     //设置当总页数为1时，是否自动隐藏控制器
54     pageCtrl.hidesForSinglePage = YES;
55     //设置控制器页码点得颜色
56     pageCtrl.pageIndicatorTintColor = [UIColor orangeColor];
57     //设置控制器当前所在页码点的颜色
58     pageCtrl.currentPageIndicatorTintColor = [UIColor greenColor];
59     pageCtrl.tag=100;
60     
61     //给pageControl添加点击事件
62     [pageCtrl addTarget:self action:@selector(turnPage:) forControlEvents:UIControlEventTouchUpInside];
63     
64 }

 1 //UIScrollViewDelegate的scrollViewDidEndDecelerating函数，用户滑动页面停下后调用该函数
 2 - (void)scrollViewWillBeginDecelerating:(UIScrollView *)ScrollView
 3 {
 4     //更新UIPageControl的当前页
 5     int current=scrollView.contentOffset.x/scrollView.frame.size.width;
 6     NSLog(@"scrollview :%f",scrollView.contentOffset.x);
 7     UIPageControl *pageControl = (UIPageControl*)[self.view viewWithTag:100];
 8     pageControl.currentPage = current;
 9     
10 }
11 
12 //点击UIPageControl时的响应函数turnPage
13 - (void)turnPage:(UIPageControl*)change{
14     ///令UIScrollView做出相应的滑动显示
15     CGSize size = scrollView.frame.size;
16     CGRect rect = (CGRect){change.currentPage*size.width,0,size.width,size.height};
17     [scrollView scrollRectToVisible:rect animated:YES];
18 
19 }