iOS开发UI篇—用纯代码写实现图片轮播

一、实现效果

实现图片的自动轮播

二、实现代码

  1 //  手写图片轮播器

  2 //

  3 //  Created by 鑫 on 14-10-9.

  4 //  Copyright (c) 2014年 梁镋鑫. All rights reserved.

  5 //

  6 #define TXImageCount 5

  7 

  8 #import "TXViewController.h"

  9 

 10 

 11 @interface TXViewController ()<UIScrollViewDelegate>

 12 {

 13     UIScrollView *_scrollView;

 14     UIPageControl *_pageControl;

 15 }

 16 @property(nonatomic ,strong)NSTimer *timer;

 17 

 18 @end

 19 

 20 @implementation TXViewController

 21 

 22 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

 23 {

 24     self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

 25     if (self) {

 26         // Custom initialization

 27     }

 28     return self;

 29 }

 30 

 31 - (void)viewDidLoad

 32 {

 33     [super viewDidLoad];

 34     

 35     

 36     _scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 85, 300, 130)];

 37     

 38     //一些固定参数

 39     CGFloat imageW = _scrollView.frame.size.width;

 40     CGFloat imageH = _scrollView.frame.size.height;

 41     CGFloat imageY = 0;

 42     _scrollView.backgroundColor = [UIColor blackColor];

 43     [self.view addSubview:_scrollView];

 44     

 45     _scrollView.delegate = self;

 46     //添加五张图片到scrollview中

 47     for (int i = 0; i<TXImageCount; i++) {

 48         UIImageView *imageView = [[UIImageView alloc] init];

 49         

 50         // 设置frame

 51         CGFloat imageX = i * imageW;

 52         imageView.frame = CGRectMake(imageX, imageY, imageW, imageH);

 53         

 54         // 设置图片

 55        NSString *name = [NSString stringWithFormat:@"img_0%d", i + 1];

 56         imageView.image = [UIImage imageNamed:name];

 57         [_scrollView addSubview:imageView];

 58         

 59         

 60         //添加定时器

 61         

 62         [self addTimer];

 63         

 64     

 65     

 66     }

 67     //添加分页点

 68     _pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(107, 128, 106, 37)];

 69     _pageControl.backgroundColor=[UIColor orangeColor];

 70     

 71     //设置pageControl的总页数

 72     

 73     _pageControl.numberOfPages = TXImageCount;

 74     

 75     [_pageControl addTarget:self action:@selector(changPage) forControlEvents:UIControlEventValueChanged];

 76     [self.view addSubview:_pageControl];

 77     //设置内容尺寸

 78     CGFloat contentW =TXImageCount *imageW;

 79     _scrollView.contentSize = CGSizeMake(contentW, 0);

 80     

 81     //隐藏水平滚动条

 82     _scrollView.showsHorizontalScrollIndicator =NO;

 83     

 84     //分页

 85     _scrollView.pagingEnabled = YES;

 86     

 87     

 88 }

 89 /**

 90  *  点击pageControl改变scrollView的页面

 91  */

 92 -(void)changPage

 93 {

 94     CGPoint offest=CGPointMake(_pageControl.currentPage*_scrollView.frame.size.width, 0);

 95     [_scrollView setContentOffset:offest animated:YES];

 96 }

 97 /**

 98  *  添加定时器

 99  */

100 -(void)addTimer

101 {

102      self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextImage) userInfo:nil repeats:YES];

103     //提高优先级

104     [[NSRunLoop currentRunLoop ] addTimer:self.timer forMode:NSRunLoopCommonModes];

105 }

106 /**

107  *  移除定时器

108  */

109 -(void)removeTimer

110 {

111     [self.timer invalidate];

112     self.timer =nil;

113 }

114 -(void)nextImage

115 {

116     //1.增加pageControl的页码

117     int page = 0;

118     if (_pageControl.currentPage ==TXImageCount-1) {

119         page = 0;

120     }

121     else

122     {

123         page = _pageControl.currentPage +1;

124     }

125     //计算scrolview滚动的位置

126     CGFloat offsetX = page *_scrollView.frame.size.width;

127     CGPoint offset = CGPointMake(offsetX, 0);

128     [_scrollView setContentOffset:offset animated:YES];

129     

130 }

131 #pragma mark  --代理方法

132 

133 -(void)scrollViewDidScroll:(UIScrollView *)scrollView

134 {

135     //根据scrollview的滚动位置决定pageControl显示第几页

136     CGFloat scrollW = _scrollView.frame.size.width;

137     

138     int page = (_scrollView.contentOffset.x+scrollW *0.5)/scrollW;

139     _pageControl.currentPage =page;

140 }

141 - (void)didReceiveMemoryWarning

142 {

143     [super didReceiveMemoryWarning];

144     // Dispose of any resources that can be recreated.

145 }

146 /**

147  *  停止拖拽时调用

148  

149  */

150 -(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

151 {

152     // 停止定时器(一旦定时器停止了,就不能再使用)

153     [self addTimer];

154 }

155 

156 /**

157  *  开始拖拽的时候调用

158  */

159 -(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView

160 {

161     // 停止定时器(一旦定时器停止了,就不能再使用)

162     [self removeTimer];

163 }

164 

165 

166 

167 @end