作为一个iOS开发者,我们经常需要用到轮播图,比如:我们首页顶部的广告轮播,商品详情页面的商品图片轮播等,如果我们每个地方都去直接定义scrollView,然后设置定时器等等操作,就会觉得很繁琐....于是就想着封装一个轮播图库FFScrollView
老惯例哈,先给出gitHub上的代码地址哈:
https://github.com/BrightMoment/FFScrollView
1.首先看下FFScrollView.h中的代码
#import <UIKit/UIKit.h>
typedef enum
{
FFScrollViewSelecttionTypeTap = 100, //默认的为可点击模式
FFScrollViewSelecttionTypeNone //不可点击的
}FFScrollViewSelecttionType;
@protocol FFScrollViewDelegate <NSObject>
@optional
- (void)scrollViewDidClickedAtPage:(NSInteger)pageNumber;
@end
@interface FFScrollView : UIView <UIScrollViewDelegate>
{
NSTimer *timer;
NSArray *sourceArr;
NSString * tagStr;
UILabel * lable1;
UILabel * lable2;
UILabel * lable3;
}
@property(strong,nonatomic) UIScrollView *scrollView;
@property(strong,nonatomic) UIPageControl *pageControl;
@property(assign,nonatomic) FFScrollViewSelecttionType selectionType;
@property(assign,nonatomic) id <FFScrollViewDelegate> pageViewDelegate;
- (id)initPageViewWithFrame:(CGRect)frame views:(NSArray *)views tag:(NSString *)tag;
@end
上面代码主要看下这部分
typedef enum
{
FFScrollViewSelecttionTypeTap = 100, //默认的为可点击模式
FFScrollViewSelecttionTypeNone //不可点击的
}FFScrollViewSelecttionType;
@protocol FFScrollViewDelegate <NSObject>
@optional
- (void)scrollViewDidClickedAtPage:(NSInteger)pageNumber;
@end
我们程序中常用的轮播图大致分为2种,一种是可以点击跳转到其他页面的;一种是只用于展示的....所以这边我们枚举了2种类型
还有一个代理FFScrollViewDelegate,主要是用来处理点击后的事件的
2.下面我们来看看FFScrollView.m文件
#import "FFScrollView.h"
@implementation FFScrollView
@synthesize scrollView;
@synthesize pageControl;
@synthesize selectionType;
@synthesize pageViewDelegate;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
}
return self;
}
#pragma mark-- init methods
- (id)initPageViewWithFrame:(CGRect)frame views:(NSArray *)views tag:(NSString *)tag
{
self = [super initWithFrame:frame];
if (self) {
selectionType = FFScrollViewSelecttionTypeTap;
sourceArr = views;
tagStr=tag;
self.userInteractionEnabled = YES;
[self iniSubviewsWithFrame:frame];
}
return self;
}
-(void)iniSubviewsWithFrame:(CGRect)frame
{
CGFloat width = frame.size.width;
CGFloat height = frame.size.height;
CGRect fitRect = CGRectMake(0, 0, width, height);
self.scrollView = [[UIScrollView alloc]initWithFrame:fitRect];
self.scrollView.pagingEnabled = YES;
self.scrollView.delegate = self;
self.scrollView.contentSize = CGSizeMake(width*(sourceArr.count+2), height);
self.scrollView.showsVerticalScrollIndicator = NO;
self.scrollView.showsHorizontalScrollIndicator = NO;
[self addSubview:self.scrollView];
UIImageView *firstImageView = [[UIImageView alloc]initWithFrame:fitRect];
[firstImageView sd_setImageWithURL:[NSURL URLWithString:[sourceArr lastObject]] placeholderImage:defaultImage640];
[self.scrollView addSubview:firstImageView];
lable2 =[[UILabel alloc] initWithFrame:CGRectMake(self.frame.size.width-80, self.frame.size.height-30, 80, 20)];
lable2.font=[UIFont systemFontOfSize:18.0f];
lable2.textColor=[UIColor whiteColor];
lable2.textAlignment=1;
// if([tagStr isEqualToString:@"home"])
// {
// [self addSubview:lable2];
// }
lable2.text=[NSString stringWithFormat:@"%zi/%zi",1,sourceArr.count];
for (int i = 0; i < sourceArr.count; i++) {
UIImageView *imageview = [[UIImageView alloc]initWithFrame:CGRectMake(width*(i+1), 0, width, height)];
[imageview sd_setImageWithURL:[NSURL URLWithString:[sourceArr objectAtIndex:i]] placeholderImage:defaultImage640];
[self.scrollView addSubview:imageview];
}
UIImageView *lastImageView = [[UIImageView alloc]initWithFrame:CGRectMake(width*(sourceArr.count+1), 0, width, height)];
[lastImageView sd_setImageWithURL:[NSURL URLWithString:[sourceArr objectAtIndex:0]] placeholderImage:defaultImage640];
[self.scrollView addSubview:lastImageView];
lable3.text=[NSString stringWithFormat:@"%zi/%zi",1,sourceArr.count];
self.pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(0, height-30, width, 30)];
self.pageControl.numberOfPages = sourceArr.count;
self.pageControl.currentPage = 0;
self.pageControl.enabled = YES;
// [self addSubview:self.pageControl];
[self.scrollView scrollRectToVisible:CGRectMake(width, 0, width, height) animated:NO];
timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage:) userInfo:nil repeats:YES];
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap:)];
singleTap.numberOfTapsRequired = 1;
[self addGestureRecognizer:singleTap];
}
#pragma mark --- custom methods
//自动滚动到下一页
-(IBAction)nextPage:(id)sender
{
CGFloat pageWidth = self.scrollView.frame.size.width;
int currentPage = self.scrollView.contentOffset.x/pageWidth;
if (currentPage == 0) {
self.pageControl.currentPage = sourceArr.count-1;
}
else if (currentPage == sourceArr.count+1) {
self.pageControl.currentPage = 0;
}
else {
self.pageControl.currentPage = currentPage-1;
}
NSInteger currPageNumber = self.pageControl.currentPage;
CGSize viewSize = self.scrollView.frame.size;
CGRect rect = CGRectMake((currPageNumber+2)*pageWidth, 0, viewSize.width, viewSize.height);
[self.scrollView scrollRectToVisible:rect animated:YES];
currPageNumber++;
if (currPageNumber == sourceArr.count) {
CGRect newRect=CGRectMake(viewSize.width, 0, viewSize.width, viewSize.height);
[self.scrollView scrollRectToVisible:newRect animated:NO];
currPageNumber = 0;
}
self.pageControl.currentPage = currPageNumber;
lable2.text=[NSString stringWithFormat:@"%zi/%zi",currPageNumber+1,sourceArr.count];
}
//点击图片的时候 触发
- (void)singleTap:(UITapGestureRecognizer *)tapGesture
{
if (selectionType != FFScrollViewSelecttionTypeTap) {
return;
}
if (pageViewDelegate && [pageViewDelegate respondsToSelector:@selector(scrollViewDidClickedAtPage:)]) {
[pageViewDelegate scrollViewDidClickedAtPage:self.pageControl.currentPage];
}
}
#pragma mark---- UIScrollView delegate methods
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
//开始拖动scrollview的时候 停止计时器控制的跳转
[timer invalidate];
timer = nil;
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
CGFloat width = self.scrollView.frame.size.width;
CGFloat heigth = self.scrollView.frame.size.height;
//当手指滑动scrollview,而scrollview减速停止的时候 开始计算当前的图片的位置
int currentPage = self.scrollView.contentOffset.x/width;
if (currentPage == 0) {
[self.scrollView scrollRectToVisible:CGRectMake(width*sourceArr.count, 0, width, heigth) animated:NO];
self.pageControl.currentPage = sourceArr.count-1;
}
else if (currentPage == sourceArr.count+1) {
[self.scrollView scrollRectToVisible:CGRectMake(width, 0, width, heigth) animated:NO];
self.pageControl.currentPage = 0;
}
else {
self.pageControl.currentPage = currentPage-1;
}
//拖动完毕的时候 重新开始计时器控制跳转
timer = [NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector:@selector(nextPage:) userInfo:nil repeats:YES];
}
上面的initPageViewWithFrame方法是我们创建这样一个轮播控件的初始化方法....
下面的代码是我们点击轮播图时的点击事件,并用代理的方式传给我们的代理对象...我们在代理对象中实现这个方法就可以了
//点击图片的时候 触发
- (void)singleTap:(UITapGestureRecognizer *)tapGesture
{
if (selectionType != FFScrollViewSelecttionTypeTap) {
return;
}
if (pageViewDelegate && [pageViewDelegate respondsToSelector:@selector(scrollViewDidClickedAtPage:)]) {
[pageViewDelegate scrollViewDidClickedAtPage:self.pageControl.currentPage];
}
}
3.我们具体看下这个控件的使用方法
- (id)initPageViewWithFrame:(CGRect)frame views:(NSArray *)views tag:(NSString *)tag
其中views这个参数我们可以传入图片的链接地址(如果图片来自于网络);自然也可以传入图片的名称
先给出创建FFScrollView的代码片段()
首先遵守这个协议@interface HomeViewController : CommonViewController<FFScrollViewDelegate>
然后
//在某个ViewController的.m文件中
-(void)addTopBanner:(NSArray *)array
{
FFScrollView *ffScroll=[[FFScrollView alloc]initPageViewWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, 150) views:array tag:@"home"];
ffScroll.pageViewDelegate=self;
[scr addSubview:ffScroll];
}
#pragma mark - FFScrollViewDelegate
-(void)scrollViewDidClickedAtPage:(NSInteger)pageNumber
{
//根据点击的图片索引pageNumber,来编写具体的点击事件
}
更详细的介绍,去查看我gitHub上的代码吧
https://github.com/BrightMoment/FFScrollView