轮播图

iOS开发实用技巧篇—项目新特性页面的处理

说明：本文主要说明在项目开发中会涉及到的最最简单的新特性界面（实用UIScrollView展示多张图片的轮播）的处理。

代码示例：

新建一个专门的处理新特性界面的控制器，可以实用代码也可以用xib，在这里实用纯代码方式，创建一个控制器NewfeatureViewController。

头文件代码：

 1 // 2 //  JMNewfeatureViewController.h 3 // 4  5 #import <UIKit/UIKit.h> 6  7 typedef enum:NSInteger 8 { 9     NewfeatureTypeFromeSetting,     //从设置界面进入该页10     NewfeatureTypeFromeWelcom,      //第一次安装的时候进入11 } NewfeatureType;12 13 @interface JMNewfeatureViewController : UIViewController14 15 @property(nonatomic,assign)NewfeatureType newfeatureType;16 17 @end

 

.m文件代码：

  1 //  2 //  JMNewfeatureViewController.m  3 //  4   5 #import "JMNewfeatureViewController.h"  6 #import "JMTabBarViewController.h"  7 #import "JMAboutTableViewController.h"  8   9 #define JMNewfeatureImageCount 4 10  11 @interface JMNewfeatureViewController () <UIScrollViewDelegate> 12  13 @property (nonatomic, weak) UIPageControl *pageControl; 14  15  16 - (void)setupScrollView; 17 - (void)setupPageControl; 18 - (void)setupLastImageView:(UIImageView *)imageView; 19 - (void)setupStartButton:(UIImageView *)imageView; 20  21 @end 22  23 @implementation JMNewfeatureViewController 24  25 #pragma mark --------------------- 26 #pragma mark - CycLife 27  28 - (void)viewDidLoad 29 { 30     [super viewDidLoad]; 31      32     [UIApplication sharedApplication].statusBarHidden = YES; 33      34     [self setupScrollView]; // 添加UISrollView 35     [self setupPageControl];    // 添加pageControl 36 } 37  38 #pragma mark --------------------- 39 #pragma mark - Methods 40  41 //添加UISrollView 42 - (void)setupScrollView 43 { 44     // 添加UISrollView 45     UIScrollView *scrollView = [[UIScrollView alloc] init]; 46     scrollView.frame = self.view.bounds; 47     scrollView.bounces = NO; 48     scrollView.delegate = self; 49     [self.view addSubview:scrollView]; 50      51     // 添加图片 52     CGFloat imageW = scrollView.width; 53     CGFloat imageH = scrollView.height; 54     for (int i = 0; i<JMNewfeatureImageCount; i++) { 55         // 创建UIImageView 56         UIImageView *imageView = [[UIImageView alloc] init]; 57         NSString *name = [NSString stringWithFormat:@"banner%d.jpg", i + 1]; 58         imageView.image = [UIImage imageNamed:name]; 59         [scrollView addSubview:imageView]; 60          61         // 设置frame 62         imageView.y = 0; 63         imageView.width = imageW; 64         imageView.height = imageH; 65         imageView.x = i * imageW; 66          67         // 给最后一个imageView添加按钮 68         if (i == JMNewfeatureImageCount - 1) { 69             [self setupLastImageView:imageView]; 70         } 71     } 72      73     // 3.设置其他属性 74     scrollView.contentSize = CGSizeMake(JMNewfeatureImageCount * imageW, 0); 75     scrollView.pagingEnabled = YES; 76     scrollView.showsHorizontalScrollIndicator = NO; 77     scrollView.backgroundColor = YYColor(246, 246, 246); 78 } 79  80 //添加pageControl 81 - (void)setupPageControl 82 { 83     // 添加PageControl 84     UIPageControl *pageControl = [[UIPageControl alloc] init]; 85     pageControl.numberOfPages = JMNewfeatureImageCount; 86     pageControl.centerX = self.view.width * 0.5; 87     pageControl.centerY = self.view.height - 20; 88     [self.view addSubview:pageControl]; 89  90     // 设置圆点的颜色 91     self.pageControl = pageControl; 92     [self changePageControlImage:self.pageControl]; 93 } 94  95  96 //设置最后一个UIImageView中的内容 97 - (void)setupLastImageView:(UIImageView *)imageView 98 { 99     imageView.userInteractionEnabled = YES;100     101     // 添加开始按钮102     [self setupStartButton:imageView];103 }104 105 //添加开始按钮106 - (void)setupStartButton:(UIImageView *)imageView107 {108     // 1.添加开始按钮109     UIButton *startButton = [[UIButton alloc] init];110     imageView.userInteractionEnabled = YES;111     [imageView addSubview:startButton];112     113     // 2.设置背景图片114     [startButton setBackgroundImage:[UIImage imageNamed:@"banner_button_moren.jpg"] forState:UIControlStateNormal];115     [startButton setBackgroundImage:[UIImage imageNamed:@"banner_button_dianji.jpg"] forState:UIControlStateHighlighted];116     117     // 3.设置frame118     startButton.size = startButton.currentBackgroundImage.size;119     startButton.centerX = self.view.width * 0.5;120     startButton.centerY = self.view.height * 0.8;121     122     // 4.设置文字123     [startButton setTitle:@"立即体验" forState:UIControlStateNormal];124      [startButton setTitle:@"" forState:UIControlStateHighlighted];125     [startButton addTarget:self action:@selector(start) forControlEvents:UIControlEventTouchUpInside];126 }127 128 129 //改变pagecontrol中圆点样式130 - (void)changePageControlImage:(UIPageControl *)pageControl131 {132     static UIImage *imgCurrent = nil;133     static UIImage *imgOther = nil;134     static dispatch_once_t onceToken;135     136     dispatch_once(&onceToken, ^{137         imgCurrent = [UIImage imageNamed:@"yuan_01"];138         imgOther = [UIImage imageNamed:@"yuan1"];139     });140     141     142     if (kSystemVersionMoreThan7) {143         [pageControl setValue:imgCurrent forKey:@"_currentPageImage"];144         [pageControl setValue:imgOther forKey:@"_pageImage"];145     } else {146         for (int i = 0;i < pageControl.numberOfPages; i++) {147             UIImageView *imgv = [pageControl.subviews objectAtIndex:i];148             imgv.frame = CGRectMake(imgv.frame.origin.x, imgv.frame.origin.y, 20, 20);149             imgv.image = pageControl.currentPage == i ? imgCurrent : imgOther;150         }151     }152 }153 154 #pragma mark ---------------------155 #pragma mark - Events156 157 //立即体验158 - (void)start159 {160     [UIApplication sharedApplication].statusBarHidden = NO;161     162     //判断类型163     if (self.newfeatureType == NewfeatureTypeFromeWelcom) {164         JMTabBarViewController *tabVC = [[JMTabBarViewController alloc]init];165         // 切换控制器166         UIWindow *window = [UIApplication sharedApplication].keyWindow;167         window.rootViewController = tabVC;168     }else 169     {170         171         [self.navigationController popViewControllerAnimated:YES];172         [self.navigationController setNavigationBarHidden:NO animated:NO];173     }174   175 }176 177 #pragma mark - UIScrollViewDelegate178 - (void)scrollViewDidScroll:(UIScrollView *)scrollView179 {180     // 获得页码181     CGFloat doublePage = scrollView.contentOffset.x / scrollView.width;182     int intPage = (int)(doublePage + 0.5);183     184     // 设置页码185     self.pageControl.currentPage = intPage;186     [self changePageControlImage:self.pageControl];187 }188 189 @end

注意点：

　　下面的方法可以为pageControl提供当前状态和默认状态下的图片设置。

 1 //改变pagecontrol中圆点样式 2 - (void)changePageControlImage:(UIPageControl *)pageControl 3 { 4     static UIImage *imgCurrent = nil; 5     static UIImage *imgOther = nil; 6     static dispatch_once_t onceToken; 7      8     dispatch_once(&onceToken, ^{ 9         imgCurrent = [UIImage imageNamed:@"yuan_01"];10         imgOther = [UIImage imageNamed:@"yuan1"];11     });12     13     14     if (kSystemVersionMoreThan7) {15         [pageControl setValue:imgCurrent forKey:@"_currentPageImage"];16         [pageControl setValue:imgOther forKey:@"_pageImage"];17     } else {18         for (int i = 0;i < pageControl.numberOfPages; i++) {19             UIImageView *imgv = [pageControl.subviews objectAtIndex:i];20             imgv.frame = CGRectMake(imgv.frame.origin.x, imgv.frame.origin.y, 20, 20);21             imgv.image = pageControl.currentPage == i ? imgCurrent : imgOther;22         }23     }24 }

本例中，新特性部分的业务逻辑非常简单，可以直接套用。