IOS中无限滚动Scrollview效果
本文实例讲了IOS无限滚动效果，分享给大家供大家参考，具体内容如下
滑动到当前位置时候才去请求，本地有内容则直接显示（以来SDWebImage,UIView+Ext）
HZScrollView.h
#import<UIKit/UIKit.h>
typedefvoid(^HZReturnBlock)(NSIntegerindex,CGFloatoffset);
typedefNS_ENUM(NSUInteger,HZScrollViewPageControllPosition){
HZScrollViewPageControllPositionNone,
HZScrollViewPageControllPositionLeft,
HZScrollViewPageControllPositionCenter,
HZScrollViewPageControllPositionRight,
};
@classHZScrollView;
@protocolHZScrollViewDelegate<NSObject>
@optional
-(void)resetPosition:(HZScrollView*)scrollViewAndIndex:(NSInteger)index;
@end
@interfaceHZScrollView:UIView
/**
*返回当前位置
*/
@property(nonatomic,weak)id<HZScrollViewDelegate>delegate;
/**
*默认图
*/
@property(nonatomic,strong)UIImage*hz_placeImage;
/**
*图片列表哇
*/
@property(nonatomic,strong)NSArray*hz_ImageList;
/**
*pagecongroll位置
*/
@property(nonatomic,assign)HZScrollViewPageControllPositionhz_PageControllPosition;
/**
*变换自身frame
*
*@paramoffset偏移量
*/
-(void)transformView:(CGFloat)offset;
/**
*获取当前位置以及便宜
*
*@paramblock返回内容
*/
-(void)hz_getContent:(HZReturnBlock)block;
@end
HZScrollView.m
#import"UIImageView+WebCache.h"
#import"HZScrollView.h"
#import"UIView+DylanFramTool.h"
#defineHZ_FormatImage(val_imageView)\
-(UIImageView*)val_imageView\
{\
if(!_##val_imageView){\
_##val_imageView=[[UIImageViewalloc]init];\
}\
return_##val_imageView;\
}\
//宽度
#defineHZ_SWidthself.bounds.size.width
//高度
#defineHZ_SHeightself.bounds.size.height
#defineHZ_PHeight16
@interfaceHZScrollView()<UIScrollViewDelegate>
@property(nonatomic,copy)HZReturnBlockhz_block;
/**
*总数
*/
@property(nonatomic,assign)NSIntegerhz_MaxCount;
/**
*当前位置
*/
@property(nonatomic,assign)NSIntegerhz_currentIndex;
/**
*容器
*/
@property(nonatomic,strong)UIScrollView*scrollView;
/**
*你懂滴
*/
@property(nonatomic,strong)UIPageControl*pageControll;
/**视图**/
@property(nonatomic,strong)UIImageView*leftImageView;
@property(nonatomic,strong)UIImageView*centerImageView;
@property(nonatomic,strong)UIImageView*rightImageView;
@end
@implementationHZScrollView
{
CGRect_hz_Frame;
}
#pragmamark-
#pragmamark-init
-(instancetype)initWithFrame:(CGRect)frame
{
self=[superinitWithFrame:frame];
if(self){
_hz_Frame=frame;
[selfaddSubview:self.scrollView];
[selfconfigImageView];
[selfaddSubview:self.pageControll];
}
returnself;
}
#pragmamark-
#pragmamark-config
-(void)configImageView
{
self.leftImageView.frame=CGRectMake(0,0,HZ_SWidth,HZ_SHeight);
[self.scrollViewaddSubview:self.leftImageView];
self.centerImageView.frame=CGRectMake(HZ_SWidth,0,HZ_SWidth,HZ_SHeight);
[self.scrollViewaddSubview:self.centerImageView];
self.rightImageView.frame=CGRectMake(HZ_SWidth*2,0,HZ_SWidth,HZ_SHeight);
[self.scrollViewaddSubview:self.rightImageView];
}
#pragmamark-
#pragmamark-reSet
-(void)setHz_placeImage:(UIImage*)hz_placeImage
{
_hz_placeImage=hz_placeImage;
[selfchangeImageLeft:-1center:-1right:-1];
if(self.hz_MaxCount){
[selfsetHz_MaxCount:self.hz_ImageList.count];
}
}
-(void)setHz_ImageList:(NSArray*)hz_ImageList
{
_hz_ImageList=[hz_ImageListcopy];
[selfsetHz_MaxCount:_hz_ImageList.count];
}
-(void)setHz_MaxCount:(NSInteger)hz_MaxCount
{
_hz_MaxCount=hz_MaxCount;
switch(_hz_MaxCount){
case0:
self.scrollView.scrollEnabled=NO;
[selfchangeImageLeft:-1center:-1right:-1];
break;
case1:
self.scrollView.scrollEnabled=NO;
[selfchangeImageLeft:0center:0right:0];
break;
default:
self.scrollView.scrollEnabled=YES;
[selfchangeImageLeft:_hz_MaxCount-1center:0right:1];
break;
}
self.pageControll.numberOfPages=_hz_MaxCount;
[selfsetHz_PageControllPosition:_hz_PageControllPosition];
}
-(void)setHz_PageControllPosition:(HZScrollViewPageControllPosition)hz_PageControllPosition
{
_hz_PageControllPosition=hz_PageControllPosition;
CGFloatwidth=self.hz_MaxCount*HZ_PHeight;
switch(_hz_PageControllPosition){
caseHZScrollViewPageControllPositionNone:
self.pageControll.hidden=YES;
break;
caseHZScrollViewPageControllPositionLeft:
self.pageControll.hidden=NO;
self.pageControll.frame=CGRectMake(10,self.pageControll.frame.origin.y,width,self.pageControll.frame.size.height);
break;
caseHZScrollViewPageControllPositionCenter:
self.pageControll.hidden=NO;
self.pageControll.frame=CGRectMake((self.bounds.size.width-width)/2.f,self.pageControll.frame.origin.y,width,self.pageControll.frame.size.height);
break;
caseHZScrollViewPageControllPositionRight:
self.pageControll.hidden=NO;
self.pageControll.frame=CGRectMake(self.bounds.size.width-10-width,self.pageControll.frame.origin.y,width,self.pageControll.frame.size.height);
break;
default:
break;
}
if(width<=HZ_PHeight){
self.pageControll.hidden=YES;
}
}
#pragmamark-
#pragmamark-LZ
-(UIScrollView*)scrollView
{
if(!_scrollView){
_scrollView=[[UIScrollViewalloc]initWithFrame:self.bounds];
_scrollView.pagingEnabled=YES;
_scrollView.showsHorizontalScrollIndicator=NO;
_scrollView.delegate=self;
_scrollView.contentSize=CGSizeMake(HZ_SWidth*3,0);
}
return_scrollView;
}
-(UIPageControl*)pageControll
{
if(!_pageControll){
_pageControll=[[UIPageControlalloc]initWithFrame:CGRectMake(0,HZ_SHeight-HZ_PHeight,HZ_PHeight,7)];
_pageControll.pageIndicatorTintColor=[UIColorlightGrayColor];
_pageControll.currentPageIndicatorTintColor=[UIColorwhiteColor];
_pageControll.numberOfPages=self.hz_MaxCount;
_pageControll.currentPage=0;
}
return_pageControll;
}
HZ_FormatImage(leftImageView);
HZ_FormatImage(centerImageView);
HZ_FormatImage(rightImageView);
#pragmamark-
#pragmamark-privateMethod
-(void)changeImageWithOffset:(CGFloat)offsetX
{
if(offsetX>=HZ_SWidth*2){
self.hz_currentIndex++;
if(self.hz_currentIndex==self.hz_MaxCount-1){
[selfchangeImageLeft:self.hz_currentIndex-1center:self.hz_currentIndexright:0];
}elseif(self.hz_currentIndex==self.hz_MaxCount){
self.hz_currentIndex=0;
[selfchangeImageLeft:self.hz_MaxCount-1center:0right:1];
}else{
[selfchangeImageLeft:self.hz_currentIndex-1center:self.hz_currentIndexright:self.hz_currentIndex+1];
}
if(self.hz_block){
self.hz_block(self.hz_currentIndex,offsetX);
}
self.pageControll.currentPage=self.hz_currentIndex;
}
if(offsetX<=0){
self.hz_currentIndex--;
if(self.hz_currentIndex==0){
[selfchangeImageLeft:self.hz_MaxCount-1center:0right:1];
}elseif(self.hz_currentIndex==-1){
self.hz_currentIndex=self.hz_MaxCount-1;
[selfchangeImageLeft:self.hz_currentIndex-1center:self.hz_currentIndexright:0];
}else{
[selfchangeImageLeft:self.hz_currentIndex-1center:self.hz_currentIndexright:self.hz_currentIndex+1];
}
if(self.hz_block){
self.hz_block(self.hz_currentIndex,offsetX);
}
self.pageControll.currentPage=self.hz_currentIndex;
}
[selfsetHz_PageControllPosition:_hz_PageControllPosition];
}
-(void)changeImageLeft:(NSInteger)leftIndexcenter:(NSInteger)centerIndexright:(NSInteger)rightIndex
{
if(self.hz_currentIndex>self.hz_MaxCount){
return;
}
if(leftIndex==-1&¢erIndex==-1&&rightIndex==-1){
self.leftImageView.image=self.hz_placeImage;
self.centerImageView.image=self.hz_placeImage;
self.rightImageView.image=self.hz_placeImage;
}else{
[selfcheckExistImage:self.hz_ImageList[leftIndex]
ImageView:self.leftImageView
CurrentIndex:@(leftIndex)];
[selfcheckExistImage:self.hz_ImageList[centerIndex]
ImageView:self.centerImageView
CurrentIndex:@(centerIndex)];
[selfcheckExistImage:self.hz_ImageList[rightIndex]
ImageView:self.rightImageView
CurrentIndex:@(rightIndex)];
}
[self.scrollViewsetContentOffset:CGPointMake(HZ_SWidth,0)];
}
-(void)checkExistImage:(NSString*)urlString
ImageView:(UIImageView*)currentImageView
CurrentIndex:(NSNumber*)index
{
if([[[SDWebImageManagersharedManager]imageCache]imageFromDiskCacheForKey:urlString])
{
currentImageView.image=[[[SDWebImageManagersharedManager]imageCache]imageFromMemoryCacheForKey:urlString];
return;
}else{
currentImageView.image=self.hz_placeImage;
if(self.hz_currentIndex!=[indexintegerValue]){
return;
}
[selfperformSelector:@selector(downLoadImage:)withObject:@[urlString,currentImageView]afterDelay:0inModes:@[NSDefaultRunLoopMode]];
}
}
-(void)downLoadImage:(NSArray*)param
{
NSString*urlString=[paramfirstObject];
__weakUIImageView*currentImageView=[paramlastObject];
[[SDWebImageManagersharedManager]downloadImageWithURL:[NSURLURLWithString:urlString]options:0progress:^(NSIntegerreceivedSize,NSIntegerexpectedSize){
NSLog(@"received:%@",@(receivedSize));
}completed:^(UIImage*image,NSError*error,SDImageCacheTypecacheType,BOOLfinished,NSURL*imageURL){
currentImageView.image=image;
//[[[SDWebImageManagersharedManager]imageCache]storeImage:imageforKey:urlString];
[[[SDWebImageManagersharedManager]imageCache]storeImage:imageforKey:urlStringtoDisk:YES];
}];
}
#pragmamark-
#pragmamark-UIScrollViewDelegate
-(void)scrollViewDidScroll:(UIScrollView*)scrollView
{
[selfchangeImageWithOffset:scrollView.contentOffset.x];
}
-(void)scrollViewDidEndDecelerating:(UIScrollView*)scrollView
{
NSIntegerindex=scrollView.contentOffset.x/scrollView.width;
if([self.delegaterespondsToSelector:@selector(resetPosition:AndIndex:)]){
[self.delegateresetPosition:selfAndIndex:self.hz_currentIndex];
}
}
#pragmamark-
#pragmamark-publicmethod
-(void)transformView:(CGFloat)offset
{
if(offset>0){
return;
}
CGFloatcurrentHeight=210-offset;
self.height=currentHeight;
CGFloatcurrentScale=currentHeight/_hz_Frame.size.height;
self.left=_hz_Frame.origin.x-(_hz_Frame.size.width*currentScale-_hz_Frame.size.width)/2.f;
self.width=_hz_Frame.size.width*currentScale;
self.top=offset;
self.scrollView.size=self.size;
self.leftImageView.size=self.size;
self.centerImageView.size=self.size;
self.rightImageView.size=self.size;
self.centerImageView.x=self.width;
self.rightImageView.x=self.width*2;
self.scrollView.contentSize=CGSizeMake(self.width*3,self.height);
[self.scrollViewsetContentOffset:CGPointMake(HZ_SWidth,0)];
}
-(void)hz_getContent:(HZReturnBlock)block
{
self.hz_block=block;
}
-(void)layoutSubviews
{
[superlayoutSubviews];
}
@end
以上就是本文的全部内容，希望对大家的学习有所帮助。