01-11 引导页（2）＝ 文顶顶
OS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。
实用图片替换pageControl的效果如下：
