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 : UIViewController
14 
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 *)imageView
107 {
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frame
118     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 *)pageControl
131 {
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 - Events
156 
157 //立即体验
158 - (void)start
159 {
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 - UIScrollViewDelegate
178 - (void)scrollViewDidScroll:(UIScrollView *)scrollView
179 {
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。