轮播器

1. .h

#import <UIKit/UIKit.h>

typedef void(^ClickImageBlock)(NSInteger currentIndex);

@interface LoopScrollView : UIView

- (instancetype)initWithFrame:(CGRect)frame imageArray:(NSArray *)imageArray clickImage:(ClickImageBlock)clickImageBlock;

- (void)invalidateTimer;

@end

2. .m

//

//  LoopScrollView.m

//  轮播器

//

//  Created by 李文良 on 2017/4/20.

//  Copyright © 2017年 王新伟. All rights reserved.

//

#define kWidth  self.frame.size.width

#define kHeight self.frame.size.height

#define kImageCount  3

#import "LoopScrollView.h"

#import "Masonry.h"

#import "UIImageView+WebCache.h"

@interface LoopScrollView()<UIScrollViewDelegate>

/**

 *滚动视图的控件

 */

@property(nonatomic,strong)UIScrollView* scroll;

/**

 *页码指示视图的控件

 */

@property(nonatomic,strong)UIPageControl* pageControl;

/**

 *显示左边图片的控件

 */

@property(nonatomic,strong)UIImageView* LeftImageView;

/**

 *显示中心图片的控件

 */

@property(nonatomic,strong)UIImageView* centerImageView;

/**

 *显示右边图片的控件

 */

@property(nonatomic,strong)UIImageView* rightImageView;

/**

 *保存图片的数组

 */

@property(nonatomic,strong)NSArray* imageArray;

/**

 *图片的当前下标索引

 */

@property(nonatomic,assign)NSInteger  currentIndex;

/**

 *图片总数

 */

@property(nonatomic,assign)NSInteger imageCount;

@property(nonatomic,strong)NSTimer *timer;

@property(nonatomic,copy)ClickImageBlock clickImageBlock;

@property(nonatomic,strong)UITapGestureRecognizer *tap;

@end

@implementation LoopScrollView

- (instancetype)initWithFrame:(CGRect)frame imageArray:(NSArray *)imageArray clickImage:(ClickImageBlock)clickImageBlock

{

    self.imageArray = imageArray;

    self.imageCount = imageArray.count;

    self.clickImageBlock = clickImageBlock;

    return [self initWithFrame:frame];

}

- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self) {

        self.currentIndex=0;

        [self createScrollView];

        [self createImageView];

        [self createPageControl];

        [self setImageByIndex:self.currentIndex];

        self.timer = [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(freshScroll) userInfo:nil repeats:YES];

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

    }

    return self;

}

/**

 *以下是搭建UI界面的方法

 */

-(void)createScrollView

{

    self.scroll=[[UIScrollView alloc]initWithFrame:CGRectMake(0, 0,kWidth, kHeight)];

    self.scroll.backgroundColor=[UIColor redColor];

    self.scroll.showsHorizontalScrollIndicator=NO;

    self.scroll.showsVerticalScrollIndicator=NO;

    self.scroll.pagingEnabled=YES;

    self.scroll.bounces=NO;

    self.scroll.delegate=self;

    self.scroll.contentOffset=CGPointMake(kWidth, 0);

    self.scroll.contentSize=CGSizeMake(kWidth*kImageCount, kHeight);

    [self addSubview:self.scroll];

    self.tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapImage:)];

    [self.scroll addGestureRecognizer:self.tap];

}

-(void)createPageControl

{

    self.pageControl = [[UIPageControl alloc] init];

    self.pageControl.currentPageIndicatorTintColor=[UIColor redColor];

    self.pageControl.pageIndicatorTintColor=[UIColor blueColor];

    self.pageControl.enabled=YES;

    self.pageControl.numberOfPages = self.imageArray.count;

    [self addSubview:self.pageControl];

    [self.pageControl mas_makeConstraints:^(MASConstraintMaker *make) {

        make.centerX.equalTo(self.mas_centerX);

        make.bottom.equalTo(self.mas_bottom).offset(-5);

        make.width.mas_equalTo(60);

        make.height.mas_equalTo(20);

    }];

}

-(void)createImageView

{

    self.LeftImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, kWidth, 220)];

    [self.scroll addSubview:self.LeftImageView];

    

    self.centerImageView=[[UIImageView alloc]initWithFrame:CGRectMake(kWidth, 0, kWidth, 220)];

    [self.scroll addSubview:self.centerImageView];

    self.centerImageView.backgroundColor = [UIColor yellowColor];

    

    self.rightImageView=[[UIImageView alloc]initWithFrame:CGRectMake(2 * kWidth, 0, kWidth, 220)];

    [self.scroll addSubview:self.rightImageView];

}

#pragma mark------定时器

- (void)freshScroll

{

    [self scrollViewDidEndDecelerating:self.scroll];

}

#pragma mark-----点击图片

- (void)tapImage:(UITapGestureRecognizer *)tap

{

    if (self.clickImageBlock) {

        self.clickImageBlock(self.currentIndex);

    }

}

- (void)invalidateTimer

{

    [self.timer invalidate];

    self.timer = nil;

    [self.tap removeTarget:self action:@selector(tapImage:)];

}

#pragma mark ----刷新图片

-(void)refreshImage

{

    if (self.scroll.contentOffset.x>=kWidth) {

        self.currentIndex=((self.currentIndex+1)%self.imageCount);

    }

    else if(self.scroll.contentOffset.x<kWidth){

        self.currentIndex=((self.currentIndex-1+self.imageCount)%self.imageCount);

    }

    [self setImageByIndex:self.currentIndex];

}

#pragma mark ----该方法根据传回的下标设置三个ImageView的图片

-(void)setImageByIndex:(NSInteger )currentIndex

{

    NSString *currentImageUrl = self.imageArray[currentIndex];

    [self.centerImageView sd_setImageWithURL:[NSURL URLWithString:currentImageUrl] placeholderImage:nil];

    

    NSString *leftImageUrl = self.imageArray[((self.currentIndex-1+self.imageCount)%self.imageCount)];

    [self.LeftImageView sd_setImageWithURL:[NSURL URLWithString:leftImageUrl] placeholderImage:nil];

    

    NSString *rightImageUrl = self.imageArray[((self.currentIndex+1)%self.imageCount)];

    [self.rightImageView sd_setImageWithURL:[NSURL URLWithString:rightImageUrl] placeholderImage:nil];

    self.pageControl.currentPage=currentIndex;

}

#pragma mark ----UIScrollViewDelegate代理方法（停止加速时调用）

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

    [self refreshImage];

    self.scroll.contentOffset = CGPointMake(kWidth,0);

    self.pageControl.currentPage = self.currentIndex;

    NSLog(@"停止了加速,停在第%ld页",self.pageControl.currentPage+1);

}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView

{

    [self.timer invalidate];

    self.timer = nil;

}

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

{

    self.timer = [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(freshScroll) userInfo:nil repeats:YES];

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

}

@end