iOS利用余弦函数实现卡片浏览工具

第iOS利用余弦函数实现卡片浏览工具_scrollView=[[UIScrollViewalloc]initWithFrame:self.bounds];

_scrollView.delegate=self;

_scrollView.showsHorizontalScrollIndicator=false;

[selfaddSubview:_scrollView];

//初始化其他参数

_cards=[[NSMutableArrayalloc]init];

_currentIndex=0;

#pragmamark-

#pragmamark视图Frame配置

//卡片宽度

-(float)cardWidth

returnviewScale*self.bounds.size.width;

//卡片间隔

-(float)margin

return(self.bounds.size.width-[selfcardWidth])/4;

//卡片起始位置

-(float)startX

return(self.bounds.size.width-[selfcardWidth])/2.0f;

#pragmamark-

#pragmamark配置轮播图片

-(void)setCardNumber:(NSInteger)cardNumber

_cardNumber=cardNumber;

//初始化各个播放器位置

for(NSIntegeri=0;icardNumber;i++){

//第一步在ScrollView上添加卡片

floatviewX=[selfstartX]+i*([selfcardWidth]+[selfmargin]);

Card*card=[[Cardalloc]initWithFrame:CGRectMake(viewX,0,[selfcardWidth],self.bounds.size.height)];

card.layer.borderWidth=1.0f;

card.index=i;

[_scrollViewaddSubview:card];

[_cardsaddObject:card];

[_scrollViewsetContentSize:CGSizeMake(card.frame.origin.x+[selfcardWidth]+2*[selfmargin],0)];

//更新卡片的大小

[selfupdateCardTransform];

#pragmamark-

#pragmamarkScrollView代理方法

//开始拖动时保存起始位置

-(void)scrollViewWillBeginDragging:(UIScrollView*)scrollView

_startPointX=scrollView.contentOffset.x;

//当ScrollView拖动时变换每个view的大小，并保证居中屏幕的view高度最高

-(void)scrollViewDidScroll:(UIScrollView*)scrollView

[selfupdateCardTransform];

//滚动结束，自动回弹到居中卡片

-(void)scrollViewDidEndDragging:(UIScrollView*)scrollViewwillDecelerate:(BOOL)decelerate

//滚动到视图中间位置

dispatch_async(dispatch_get_main_queue(),^{

[selfscrollToCurrentCard];

//卡片自动居中

-(void)scrollToCurrentCard

_endPointX=_scrollView.contentOffset.x;

//设置滚动最小生效范围，滚动超过scrollMiniDistance即视为有切换卡片的意向

floatscrollMiniDistance=self.bounds.size.width/30.0f;

if(_startPointX-_endPointXscrollMiniDistance){

NSLog(@向右滑动屏幕

if(_currentIndex!=0){

_currentIndex-=1;

}elseif(_endPointX-_startPointXscrollMiniDistance)

NSLog(@向左滑动屏幕

if(_currentIndex!=_cards.count-1){

_currentIndex+=1;

floatviewX=[selfstartX]+_currentIndex*([selfcardWidth]+[selfmar