简易轮播图的实现(前后各加一张假图的方式)

// 项目中轮播图的登场率还是很大的，之前有用到轮播三方 但看他源码的时候发现 创建了好多组数据 这无形中浪费了一部分内存

// 其实轮播图的实现也算是很简单的了 今天就带大家做一个简易的轮播图

// 实现功能：带定时器 可以手动拖拽 手动拖拽定时器停止 手动拖拽结束一定时间 定时器重新启动

// 创建一个UIView 子类JWCarouselFigureView

// JWCarouselFigureView.h

#import <UIKit/UIKit.h>

@interface JWCarouselFigureView : UIView

/*图片数组*/

@property(copy,nonatomic)NSArray *pics;

/*标题数组*/

@property(copy,nonatomic)NSArray *titles;

/*轮播时间间隔*/

@property(assign,nonatomic)NSInteger sec;

/*拖拽结束重新开启定时器间隔*/

@property(assign,nonatomic)NSInteger secNew;

/*点击回传*/

@property(copy,nonatomic)void(^CallBack)(NSInteger index);

@end

// JWCarouselFigureView.m具体实现

#import "JWCarouselFigureView.h"

#import "JWCollectionViewCell.h"

#define kWIDTH [UIScreen mainScreen].bounds.size.width

#define kSEC 3

@interface JWCarouselFigureView()<UICollectionViewDataSource,UICollectionViewDelegate>

@property(nonatomic,strong)UICollectionView *collectionView;

@property(assign,nonatomic,getter=isStart)BOOL start;// 判断定时器状态 防止多次创建

@property(weak,nonatomic)NSTimer *timer;

@end

@implementation JWCarouselFigureView

- (instancetype)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

#pragma - mark collectioView初始化

UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];

layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;

layout.itemSize = CGSizeMake(self.frame.size.width, self.frame.size.height);

layout.minimumInteritemSpacing = 0;

layout.minimumLineSpacing = 0;

layout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0);

UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:frame collectionViewLayout:layout];

collectionView.delegate = self;

collectionView.pagingEnabled = YES;

collectionView.dataSource = self;

self.collectionView = collectionView;

[collectionView registerNib:[UINib nibWithNibName:@"JWCollectionViewCell" bundle:nil] forCellWithReuseIdentifier:@"JWCollectionViewCell"];

// 第一个出现的是第二个item也就是数据的第一条数据

collectionView.contentOffset = CGPointMake(frame.size.width, 0);

[self addSubview:collectionView];

// 初始化定时器

[self setUpTimer];

}

return self;

}

#pragma - collectionView协议方法

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

JWCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"JWCollectionViewCell" forIndexPath:indexPath];

return [self setDataForCell:cell IndexPath:indexPath];

}

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView

{

return 1;

}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

return self.pics.count + 2;

}

#pragma - mark cell赋值

- (UICollectionViewCell *)setDataForCell:(JWCollectionViewCell *)cell IndexPath:(NSIndexPath *)indexPath

{

#pragma - mark 判断是第几个cell 第一个cell赋数组最后一个数据,最后一个cell赋值数组第一个数据

NSInteger count = self.pics.count;

if (indexPath.item == 0) {

cell.url = [self.pics lastObject];

cell.title = self.titles.count > 0 ? [self.titles lastObject]:nil;

cell.num = [NSString stringWithFormat:@"%ld/%ld",(unsigned long)self.pics.count,(unsigned long)self.pics.count];

} else if(indexPath.item == count + 1){

cell.url = [self.pics firstObject];

cell.title = self.titles.count > 0 ? [self.titles firstObject]:nil;

cell.num = [NSString stringWithFormat:@"1/%ld",(unsigned long)self.pics.count];

} else

{

cell.url = [self.pics objectAtIndex:indexPath.item - 1];

cell.title = self.titles.count > 0 ? [self.titles objectAtIndex:indexPath.item - 1]:nil;

cell.num = [NSString stringWithFormat:@"%ld/%ld",(long)indexPath.item,(unsigned long)self.pics.count];

}

return cell;

}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

NSInteger index = scrollView.contentOffset.x / kWIDTH;

#pragma - 手动滑动时候判断滑到第几张 执行相应的跳转

if (index == self.pics.count + 1) {

self.collectionView.contentOffset = CGPointMake(kWIDTH * 1, 0);

} else if(index == 0){

self.collectionView.contentOffset = CGPointMake(kWIDTH * self.pics.count, 0);

}

}

#pragma mark - 定时器创建方法

- (void)setUpTimer

{

if (!_start) {

NSInteger sec = self.sec > 0 ? self.sec : kSEC;

self.timer = [NSTimer timerWithTimeInterval:sec target:self selector:@selector(timerActionMethod) userInfo:nil repeats:YES];

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

_start = !_start;

}

}

// 定时器关联方法

- (void)timerActionMethod

{

NSInteger index = self.collectionView.contentOffset.x / kWIDTH;

NSInteger pointX = 0;

if (index == self.pics.count + 1) {

} else{

pointX = (index + 1) * kWIDTH;

}

self.collectionView.contentOffset = CGPointMake(pointX, 0);

}

#pragma - mark 拖拽开始 关闭定时器

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{

[self.timer invalidate];

self.start = !self.start;

}

#pragma - mark 拖拽结束后 重新创建定时器

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

{

NSInteger sec = self.secNew > 0 ? self.sec : 2 * kSEC;

[self performSelector:@selector(setUpTimer) withObject:nil afterDelay:sec];

}

#pragma - 点击回调

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath

{

NSLog(@"%ld",(long)indexPath.item);

if (self.CallBack) {

if (indexPath.item == 0) {

self.CallBack(self.pics.count - 1);

} else if(indexPath.item == self.pics.count + 1){

self.CallBack(0);

}else

{

self.CallBack(indexPath.item - 1);

}

}

}

@end

// 自定义cell JWCollectionViewCell.h

#import <UIKit/UIKit.h>

@interface JWCollectionViewCell : UICollectionViewCell

@property(copy,nonatomic)NSString *url;

@property(copy,nonatomic)NSString *title;

@property(copy,nonatomic)NSString *num;

@end

// 自定义cell JWCollectionViewCell.m

#import "JWCollectionViewCell.h"

#import "UIImageView+WebCache.h"

@interface JWCollectionViewCell ()

@property (weak, nonatomic) IBOutlet UIImageView *imgMain;

@property (weak, nonatomic) IBOutlet UILabel *picNum;

@property (weak, nonatomic) IBOutlet UILabel *lableTitle;

@end

@implementation JWCollectionViewCell

- (void)awakeFromNib {

// Initialization code

}

- (void)setUrl:(NSString *)url

{

_url = url;

[self.imgMain sd_setImageWithURL:[NSURL URLWithString:_url]];

}

- (void)setTitle:(NSString *)title

{

_title = title;

if ([_title isEqualToString:@""]) {

[self.lableTitle removeFromSuperview];

} else {

self.lableTitle.text = _title;

self.lableTitle.textColor = [UIColor redColor];

}

}

- (void)setNum:(NSString *)num

{

_num = num;

self.picNum.text = _num;

self.picNum.textColor = [UIColor redColor];

self.picNum.textAlignment = NSTextAlignmentRight;

}

@end

/ 自定义cell xib拖的 简单做了下约束

// 调用的ViewController

#import "ViewController.h"

#import "JWCarouselFigureView.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

NSArray *picUrls = [NSArray arrayWithObjects:@"http://imgstore.cdn.sogou.com/app/a/100540002/910829.jpg",@"http://bbsimg.tianshi2.net/forum/201410/20/102633tuegrhtk6ldsx6yq.jpg",@"http://cdn.duitang.com/uploads/item/201510/05/20151005204527_VEriN.jpeg",@"http://imgsrc.baidu.com/forum/pic/item/644a1bce36d3d539ca201e213a87e950342ab057.jpg",@"http://img5.duitang.com/uploads/item/201412/27/20141227212121_waEPy.png",
nil];

NSArray *picNames = [NSArray arrayWithObjects:@"椎名真白",@"艾斯德斯",@"友利奈绪",@"十六夜咲夜",@"远坂凛", nil];

JWCarouselFigureView *view = [[JWCarouselFigureView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height * 2 / 5)];

view.pics = picUrls;

view.titles = picNames;

view.CallBack = ^(NSInteger index)

{

NSLog(@"点的是%@",picNames[index]);

};

[self.view addSubview:view];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

代码地址：https://github.com/xueZhiXiaWeiLiang/JWCarouselFigureView