首先声明本篇博客是个人原创，绝非抄袭。
自定义实现轮播图
轮播图一般实现在一款App的首页的最上部分，能够来回滚动的图片，通常这些图片都对应一个网络Url ,用户点击的时候，能够跳转到对应的UIwebView页面。轮播图也可以使用在用户引导页面，只不过这时候轮播图的大小是全屏的，用户可以在轮播图上放一些控件，用来收集用户的信息，当用户进入程序的时候，可以根据这些信息，加载相应的版块内容，或者推荐相应的推送。轮播图也可以在相框的程序中用到，也可以在新闻类App中对应一个专题的整页的滑动，总之轮播图增添了App的用户体验效果，是必不可少的一个技术实现。
本文的轮播图采用工具：
UIScrollView（用于实现轮播效果）、UILabel（用于显示当前是第几张）、NSTimer（用于实现自动轮播）采用封装的思想，降低耦合度，将该功能组件化。
目前实现的功能相对来说比较简单，功能如下：
能够设置轮播图的位置大小、设置录播的一组图片用数组实现、是否自动轮播、自动轮播间隔时间。
使用：
首先引入ScrollerImage.h 和 ScrollerImage.m文件到工程中
调用接口：
-(id)initWithFrame:(CGRect)frame
Arrary:(NSArray *)imageArr
isAutomLunBo:(BOOL)isYes
setLunBoTime:(NSInteger)intervalTime;
例如：
在一个视图控制器中
#import 'ScrollerImage.h'//引入自定义轮播图
@property(nonatomic,strong)ScrollerImage * myImageViewScroller;
//轮播图的图片数组
NSArray * arrImg = @[@'1.png',@'2.png',@'3.png',@'4.png',@'5.png',@'6.png',@'7.png',@'8.png',@'9.png'];
self.myImageViewScroller = [[ScrollerImage alloc]initWithFrame:view.frame Arrary:arrImg isAutomLunBo:NO setLunBoTime:2.3];
[view addSubview:self.myImageViewScroller];
代码：
#import <UIKit/UIKit.h>
@interface ScrollerImage : UIView<UIScrollViewDelegate>
@property(assign)NSInteger count;
-(id)initWithFrame:(CGRect)frame
Arrary:(NSArray *)imageArr
isAutomLunBo:(BOOL)isYes
setLunBoTime:(NSInteger)intervalTime;
-(void)dealloc;
@end
ScrollerImage.h
#import 'ScrollerImage.h'
@interface ScrollerImage ()
@property (strong, nonatomic) UIScrollView *scroll;
@property (strong, nonatomic) UILabel *toKonwCurrentPageLabel;
@property(strong,nonatomic)NSTimer * timer;
@property(assign)int n;
@end
@implementation ScrollerImage
//自定义轮播图
-(id)initWithFrame:(CGRect)frame Arrary:(NSArray *)imageArr isAutomLunBo:(BOOL)isYes setLunBoTime:(NSInteger)intervalTime;{
if ([super init]) {
self.frame = frame;
}
self.count = imageArr.count;
CGFloat kWidth = self.frame.size.width;
CGFloat kHeight = self.frame.size.height;
//滑块
self.scroll = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, kWidth, kHeight)];
self.scroll.contentSize = CGSizeMake(kWidth * imageArr.count, kHeight);
self.scroll.pagingEnabled = YES;
self.scroll.delegate = self;
self.scroll.scrollEnabled = YES;
[self addSubview:self.scroll];
//显示图片张数
self.toKonwCurrentPageLabel = [[UILabel alloc]initWithFrame:CGRectMake(kWidth - 90, kHeight - 30, 60, 20)];
self.toKonwCurrentPageLabel.layer.masksToBounds = YES;
self.toKonwCurrentPageLabel.layer.cornerRadius = 11;
self.toKonwCurrentPageLabel.backgroundColor = [UIColor blackColor];
self.toKonwCurrentPageLabel.textColor = [UIColor whiteColor];
self.toKonwCurrentPageLabel.textAlignment = NSTextAlignmentCenter;
self.toKonwCurrentPageLabel.font = [UIFont systemFontOfSize:12];
self.toKonwCurrentPageLabel.alpha = 0.3;
self.toKonwCurrentPageLabel.text = [NSString stringWithFormat:@'1/共%lu张',self.count];
for (int i = 0; i < imageArr.count; i++) {
UIImageView * viewImage = [[UIImageView alloc]initWithFrame:CGRectMake(i*kWidth, 0, kWidth, kHeight)];
viewImage.image = [UIImage imageNamed:imageArr[i]];
[self.scroll addSubview:viewImage];
}
[self.scroll addSubview:self.toKonwCurrentPageLabel];
[self.scroll bringSubviewToFront:self.toKonwCurrentPageLabel];
//轮播效果
if (isYes == YES) {
self.timer = [NSTimer timerWithTimeInterval:intervalTime target:self selector:@selector(LunBoAction:) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];
}
self.n = 0;//初始化轮播位置
return self;
}
//LunBo
-(void)LunBoAction:(NSTimer *)sender{
self.n +=1;
self.scroll.contentOffset = CGPointMake(self.scroll.frame.size.width * (self.n % (int)self.count), 0);
int i = self.n %(int)self.count;
[self setLabelWith:i contentOffset:self.scroll.frame.size.width andHeight:self.scroll.frame.size.height];
if (self.n == self.count) {
self.n = 0;
}
}
//人为滑动图片
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
CGFloat width = scrollView.frame.size.width;
CGFloat height = scrollView.frame.size.height;
self.n = scrollView.contentOffset.x/width;
[self setLabelWith:self.n contentOffset:width andHeight:height];
}
-(void)setLabelWith:(int)i contentOffset:(CGFloat)width andHeight:(CGFloat)height{
self.toKonwCurrentPageLabel.text = [NSString stringWithFormat:@'%d/共%lu张',i+1,self.count];
self.toKonwCurrentPageLabel.frame = CGRectMake(width*(i + 1) - 90, height - 30 , 60, 20);
}
-(void)dealloc{
self.timer = nil;
[self.timer invalidate];
}
@end
ScrollerImage.m
效果截图：
自定义集合控件的实现
集合视图也能够实现轮播图，我觉得有时间再次研究轮播图的实现，下面使用到集合视图是解决这类问题，看下面的两幅图片，左边的是在请求数据后解析的结果没有录播图，并且上面四个主题“附近的贴”“精编推荐”。。是不固定的主题，有可能某一天主题变化为两个，下面6个主题的板块主题个数也是有可能变化的。右边的图片中，有轮播图，上下两个板块的功能与图片一中的是一样的。
技术点分析：
首先因为主题有可能要变化，根据界面的设计需求，所以最好是使用集合视图UICollectionView 实现。而是否有轮播图可以使用一个布尔值判断，如果有轮播图就开启集合视图的页眉，如果没有就关闭集合视图的页眉，并动态的改变位置。比较难以实现的是，如何在一个 UIViewController 中实现有两个 UICollectionView
，对于这个问题，可以在 UICollectionViewDelegate 的协议方法中，根据可重用ID做一下判断即可。
实现功能的全部源代码：
需要源代码的园友可以在左侧QQ我哦，如有转载请说明出处，谢谢。
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@end
ViewController.m
#import 'ViewController.h'
#import 'Cell.h'
#import 'HeaderView.h'
#import 'FooterView.h'
#import 'ScrollerImage.h'//引入自定义轮播图
@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
{
BOOL isHaveLunBo;//判断是否有轮播图
}
@property(nonatomic,strong)UIScrollView * scroll;
@property(nonatomic,strong)ScrollerImage * myImageViewScroller;
@property(nonatomic,strong)UICollectionView * collectionView1;
@property(nonatomic,strong)UICollectionView * collectionView2;
//测试数据
@property(nonatomic,strong)NSMutableArray * arrayOfTestDataSouce1;
@property(nonatomic,strong)NSMutableArray * arrayOfTestDataSouce2;
@end
@implementation ViewController
//-lazy
-(NSMutableArray *)arrayOfTestDataSouce1{
if (_arrayOfTestDataSouce1 == nil) {
//我在这里给数据添加数据，可以在请求到数据后再添加数据
NSArray * testArr = @[@'A',@'B',@'C',@'D'];
self.arrayOfTestDataSouce1 = [NSMutableArray arrayWithArray:testArr];
NSLog(@'%@',self.arrayOfTestDataSouce1);
}
return _arrayOfTestDataSouce1;
}
-(NSMutableArray *)arrayOfTestDataSouce2{
if (_arrayOfTestDataSouce2 == nil) {
//我在这里给数据添加数据，可以在请求到数据后再添加数据
NSArray * testArr = @[@'AA',@'BB',@'CC',@'DD',@'EE',@'FF'];
self.arrayOfTestDataSouce2 = [NSMutableArray arrayWithArray:testArr];
NSLog(@'%@',self.arrayOfTestDataSouce2);
}
return _arrayOfTestDataSouce2;
}
- (void)viewDidLoad {
[super viewDidLoad];
//关闭毛玻璃效果
self.navigationController.navigationBar.translucent = NO;
//添加 集合视图1
UIView * vi = [[UIView alloc] init];
vi.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 125);
vi.backgroundColor = [UIColor redColor];
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
//配置属性
//1.设置每个item的大小
layout.itemSize = CGSizeMake(self.view.bounds.size.width / 2 - 10, 50);
//2.设置缩进量 （上，左，下，右）
layout.sectionInset = UIEdgeInsetsMake(0, 5, 0, 5);
//3.设置行的最小间距
layout.minimumLineSpacing = 2.5;
//4.设置item的最小间距
layout.minimumInteritemSpacing = 10;
self.collectionView1 = [[UICollectionView alloc] initWithFrame:vi.frame collectionViewLayout:layout];
//这里巨坑啊，设定代理一定要写到初始化集合视图的下面
self.collectionView1.delegate = self;
self.collectionView1.dataSource = self;
self.collectionView1.backgroundColor = [UIColor brownColor];
[vi addSubview:self.collectionView1];
[self.view addSubview:vi];
//判断是否有轮播图(默认有-YES)
isHaveLunBo = YES;
//添加 集合视图2
UICollectionViewFlowLayout *layout2 = [[UICollectionViewFlowLayout alloc] init];
//配置属性
//1.设置每个item的大小
layout2.itemSize = CGSizeMake(50, 50);
//2.设置缩进量 （上，左，下，右）
layout2.sectionInset = UIEdgeInsetsMake(0, 5, 0, 5);
//3.设置行的最小间距
layout2.minimumLineSpacing = 10;
//4.设置item的最小间距
layout2.minimumInteritemSpacing = 10;
//设置大小
if (isHaveLunBo) {
self.collectionView2 = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 125, self.collectionView1.frame.size.width, 180 + 125) collectionViewLayout:layout2];
}else{
self.collectionView2 = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 125, self.collectionView1.frame.size.width, 180) collectionViewLayout:layout2];
}
self.collectionView2.delegate = self;
self.collectionView2.dataSource = self;
[self.view addSubview:self.collectionView2];
//注册cell
[self.collectionView1 registerClass:[Cell class] forCellWithReuseIdentifier:@'item1'];
[self.collectionView2 registerClass:[Cell class] forCellWithReuseIdentifier:@'item2'];
//注册页眉
[self.collectionView1 registerClass:[HeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@'header'];
[self.collectionView2 registerClass:[FooterView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@'footer'];
//注册页脚
[self.collectionView2 registerClass:[HeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@'header'];
[self.collectionView2 registerClass:[FooterView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@'footer'];
}
#pragma mark - UICollectionViewDataSource -
//设置分区的item数目
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
if (collectionView == self.collectionView1) {
return self.arrayOfTestDataSouce1.count;
}
else {
return self.arrayOfTestDataSouce2.count;
}
}
//设置分区数目
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
if (collectionView == self.collectionView1) {
return 1;
}
else {
return 1;
}
}
#pragma Mark======设置自定义的cell
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
if (collectionView == self.collectionView1) {
Cell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@'item1' forIndexPath:indexPath];
cell.lab.text = self.arrayOfTestDataSouce1[indexPath.item];
cell.lab.frame = cell.bounds;
return cell;
}
else {
Cell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@'item2' forIndexPath:indexPath];
cell.lab.text = self.arrayOfTestDataSouce2[indexPath.item];
return cell;
}
}
#pragma Mark======设置页眉与页脚的视图
-(UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{
if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {
if (collectionView == self.collectionView2) {
//返回页眉
HeaderView * view = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@'header' forIndexPath:indexPath];
//view.titleLabel.text = @'页眉，可以在黄色区域放轮播图';
if (isHaveLunBo == YES) {
//轮播图的图片数组
NSArray * arrImg = @[@'1.png',@'2.png',@'3.png',@'4.png',@'5.png',@'6.png',@'7.png',@'8.png',@'9.png'];
self.myImageViewScroller = [[ScrollerImage alloc]initWithFrame:view.frame Arrary:arrImg isAutomLunBo:NO setLunBoTime:2.3];
[view addSubview:self.myImageViewScroller];
return view;
}else{
return nil;
}
}else{
return nil;
}
} else {
//返回页脚
// FooterView *footer = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@'footer' forIndexPath:indexPath];
// footer.footerLabel.text = @'页脚';
// return footer;
return nil;
}
}
#pragma mark - UICollectionViewDelegateFlowLayout -
//动态配置每个分区的item的size大小
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0) {
return CGSizeMake((self.view.frame.size.width - 15)/2, 50);
}
return CGSizeMake((self.view.frame.size.width - 60)/3, 50);
}
//动态配置item的缩进量
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
if (section == 0) {
//上、左、下、右
return UIEdgeInsetsMake(10, 5, 10, 5);
}
return UIEdgeInsetsMake(10, 5, 10, 5);
}
//动态配置item 左右最小间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 5;
}
//动态配置行的最小间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 5;
}
//动态的设置页眉
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section{
if (collectionView == self.collectionView1) {
//这里也可以仿照下面写法，为 collectionView1 设定是否添加页眉
return CGSizeMake(0, 0);
}else{
if (isHaveLunBo) {
return CGSizeMake(20, 100);
}else{
return CGSizeMake(0, 0);
}
}
}
//动态的设置页脚
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section{
return CGSizeMake(0, 0);
}
#pragma mark - UICollectionViewDelegate -
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
//选中某一行的点击事件写这里
NSLog(@'选择了');
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
ViewController.m
#import <UIKit/UIKit.h>
@interface ScrollerImage : UIView<UIScrollViewDelegate>
@property(assign)NSInteger count;
-(id)initWithFrame:(CGRect)frame
Arrary:(NSArray *)imageArr
isAutomLunBo:(BOOL)isYes
setLunBoTime:(NSInteger)intervalTime;
-(void)dealloc;
@end
ScrollerImage.h
#import 'ScrollerImage.h'
@interface ScrollerImage ()
@property (strong, nonatomic) UIScrollView *scroll;
@property (strong, nonatomic) UILabel *toKonwCurrentPageLabel;
@property(strong,nonatomic)NSTimer * timer;
@property(assign)int n;
@end
@implementation ScrollerImage
//自定义轮播图
-(id)initWithFrame:(CGRect)frame Arrary:(NSArray *)imageArr isAutomLunBo:(BOOL)isYes setLunBoTime:(NSInteger)intervalTime;{
if ([super init]) {
self.frame = frame;
}
self.count = imageArr.count;
CGFloat kWidth = self.frame.size.width;
CGFloat kHeight = self.frame.size.height;
//滑块
self.scroll = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, kWidth, kHeight)];
self.scroll.contentSize = CGSizeMake(kWidth * imageArr.count, kHeight);
self.scroll.pagingEnabled = YES;
self.scroll.delegate = self;
self.scroll.scrollEnabled = YES;
[self addSubview:self.scroll];
//显示图片张数
self.toKonwCurrentPageLabel = [[UILabel alloc]initWithFrame:CGRectMake(kWidth - 90, kHeight - 30, 60, 20)];
self.toKonwCurrentPageLabel.layer.masksToBounds = YES;
self.toKonwCurrentPageLabel.layer.cornerRadius = 11;
self.toKonwCurrentPageLabel.backgroundColor = [UIColor blackColor];
self.toKonwCurrentPageLabel.textColor = [UIColor whiteColor];
self.toKonwCurrentPageLabel.textAlignment = NSTextAlignmentCenter;
self.toKonwCurrentPageLabel.font = [UIFont systemFontOfSize:12];
self.toKonwCurrentPageLabel.alpha = 0.3;
self.toKonwCurrentPageLabel.text = [NSString stringWithFormat:@'1/共%lu张',self.count];
for (int i = 0; i < imageArr.count; i++) {
UIImageView * viewImage = [[UIImageView alloc]initWithFrame:CGRectMake(i*kWidth, 0, kWidth, kHeight)];
viewImage.image = [UIImage imageNamed:imageArr[i]];
[self.scroll addSubview:viewImage];
}
[self.scroll addSubview:self.toKonwCurrentPageLabel];
[self.scroll bringSubviewToFront:self.toKonwCurrentPageLabel];
//轮播效果
if (isYes == YES) {
self.timer = [NSTimer timerWithTimeInterval:intervalTime target:self selector:@selector(LunBoAction:) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];
}
self.n = 0;//初始化轮播位置
return self;
}
//LunBo
-(void)LunBoAction:(NSTimer *)sender{
self.n +=1;
self.scroll.contentOffset = CGPointMake(self.scroll.frame.size.width * (self.n % (int)self.count), 0);
int i = self.n %(int)self.count;
[self setLabelWith:i contentOffset:self.scroll.frame.size.width andHeight:self.scroll.frame.size.height];
if (self.n == self.count) {
self.n = 0;
}
}
//人为滑动图片
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
CGFloat width = scrollView.frame.size.width;
CGFloat height = scrollView.frame.size.height;
self.n = scrollView.contentOffset.x/width;
[self setLabelWith:self.n contentOffset:width andHeight:height];
}
-(void)setLabelWith:(int)i contentOffset:(CGFloat)width andHeight:(CGFloat)height{
self.toKonwCurrentPageLabel.text = [NSString stringWithFormat:@'%d/共%lu张',i+1,self.count];
self.toKonwCurrentPageLabel.frame = CGRectMake(width*(i + 1) - 90, height - 30 , 60, 20);
}
-(void)dealloc{
self.timer = nil;
[self.timer invalidate];
}
@end
ScrollerImage.m 
#import <UIKit/UIKit.h>
@interface FooterView : UICollectionReusableView
@property (nonatomic, retain) UILabel *footerLabel;
@end
FooterView.h
#import 'FooterView.h'
@implementation FooterView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self addSubview:self.footerLabel];
}
return self;
}
- (UILabel *)footerLabel {
if (!_footerLabel) {
self.footerLabel = [[UILabel alloc] initWithFrame:self.bounds];
_footerLabel.backgroundColor = [UIColor greenColor];
}
return _footerLabel;
}
@end
FooterView.m
#import <UIKit/UIKit.h>
@interface HeaderView : UICollectionReusableView
@property (nonatomic, retain) UILabel *titleLabel;
@end
HeaderView.h
#import 'HeaderView.h'
@implementation HeaderView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self addSubview:self.titleLabel];
}
return self;
}
- (UILabel *)titleLabel {
if (!_titleLabel) {
self.titleLabel = [[UILabel alloc] initWithFrame:self.bounds];
_titleLabel.backgroundColor = [UIColor yellowColor];
}
return _titleLabel;
}
@end
HeaderView.m
#import <UIKit/UIKit.h>
@interface Cell : UICollectionViewCell
@property(nonatomic,strong)UILabel * lab;
@end
Cell.h
#import 'Cell.h'
@implementation Cell
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
//按照此格式，添加一些其他控件
[self.contentView addSubview:self.lab];
}
return self;
}
- (UILabel *)lab {
if (!_lab) {
self.lab = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
//测试颜色
_lab.backgroundColor = [UIColor greenColor];
_lab.textAlignment = NSTextAlignmentCenter;
_lab.font = [UIFont systemFontOfSize:15];
}
return _lab;
}
@end
Cell.m
源代码实现效果：
左边图片假设没有请求到轮播图，右边图片假设请求到轮播图，关键代码
isHaveLunBo = YES;如果为NO，不显示录播图，具体情况根据网络请求结果处理，这里仅仅模拟效果。
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