1 #import "RootViewController.h"
2
3 #define width [UIScreen mainScreen].bounds.size.width
4 #define heigthY 150
5
6 @interface RootViewController ()<UIScrollViewDelegate>
7 {
8 UIScrollView *_scrollView;
9 NSMutableArray *imageArray;
10 UIPageControl *pageControl;
11 }
12 @end
13
14 @implementation RootViewController
15
16 - (void)dealloc
17 {
18 imageArray = nil;
19 [super dealloc];
20 }
21
22 - (void)loadView
23 {
24 [super loadView];
25 _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, width, heigthY)];
26 _scrollView.pagingEnabled = YES;
27 _scrollView.delegate = self;
28 // 开始时选中第二个图片 图片的布局[3-1-2-3-1]
29 _scrollView.contentOffset = CGPointMake(width, 0);
30 // 隐藏水平滚动条
31 _scrollView.showsHorizontalScrollIndicator = NO;
32
33 pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(width - 100,heigthY - 50, 100, 50)];
34 // 设置pageControl不支持用户操作
35 pageControl.userInteractionEnabled = NO;
36 pageControl.currentPageIndicatorTintColor = [UIColor redColor];
37 pageControl.pageIndicatorTintColor = [UIColor greenColor];
38 [self.view addSubview:_scrollView];
39 [self.view addSubview:pageControl];
40 [_scrollView release];
41 [pageControl release];
42
43 }
44
45 - (void)viewDidLoad {
46 [super viewDidLoad];
47 imageArray = [[NSMutableArray alloc] init];
48 NSArray *tempArray = @[@"1-3.jpg",@"1-1.jpg",@"1-2.jpg",@"1-3.jpg",@"1-1.jpg"];
49 [imageArray addObjectsFromArray:tempArray];
50 // 根据imageArray的数量设置_scrollView的内容大小
51 _scrollView.contentSize = CGSizeMake(width * imageArray.count, heigthY);
52 pageControl.numberOfPages = imageArray.count - 2;
53 // 给_scrollView添加图片
54 [self addImagesWithScrollView];
55 }
56
57 /**
58 * 给scrollView添加图片
59 */
60 - (void)addImagesWithScrollView
61 {
62 for (int i = 0; i < imageArray.count; i++) {
63 UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageArray[i]]];
64 imageView.frame = CGRectMake(i * width, 0, width, heigthY);
65 [_scrollView addSubview:imageView];
66 [imageView release];
67 }
68 }
69
70 #pragma mark - UIScrollViewDelegate的方法
71 - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
72 {
73 int imageIndex = scrollView.contentOffset.x / width;
74 if (imageIndex == 0) {
75 // 滚到第一张图片时，就跳转到倒数第二张图片
76 [_scrollView scrollRectToVisible:CGRectMake((imageArray.count - 2)*width, 0, width, heigthY) animated:NO];
77 }else if (imageIndex == imageArray.count - 1){
78 // 滚动到最后一张图片时，就跳转到第二张图片
79 [_scrollView scrollRectToVisible:CGRectMake(width, 0, width, heigthY) animated:NO];
80 }
81 }
82
83 /**
84 * 设置pageControl的当前页
85 */
86 - (void)scrollViewDidScroll:(UIScrollView *)scrollView
87 {
88 // 加0.5是为了用户体验好些，滑动过程中哪张图片占优就显示占优图片对应的下标
89 int imageIndex = scrollView.contentOffset.x / width + 0.5;
90 if (imageIndex == 0) {
91 // 设置相应的下标（使之减1后与pageControl的下标相对应）
92 imageIndex = imageArray.count - 1;
93 }else if (imageIndex == imageArray.count - 1){
94 // 设置相应的下标（使之减1后与pageControl的下标相对应）
95 imageIndex = 1;
96 }
97 pageControl.currentPage = imageIndex - 1;
98 }
99 @end
