我自己写的Uiscrollview无限滚动

头文件 ：

#import <UIKit/UIKit.h>

@interface ScreenView :
UIView <UIScrollViewDelegate>
- (void)refreshData:(NSMutableArray*)imagesArray;
@end

实现文件 ：

#import "ScreenView.h"

@interface ScreenView ()
{
    NSMutableArray*     _screenArray; 
//图片数组
    NSInteger           _totalInt;    
//图片总数
    NSInteger           _currentInt;  
//当前页面
    NSMutableArray*     _currentArray;
//当前图片数组  最多三个
    UIScrollView*       _scrollView;
}
@property (nonatomic,retain)NSMutableArray*  screenArray; //图片数组
@end

@implementation ScreenView
@synthesize screenArray =
_screenArray;

#pragma mark --
#pragma mark LifeStyle
- (id)initWithFrame:(CGRect)frame
{
    self = [super
initWithFrame:frame];
    if (self) {
        // Initialization code
        //初始化uiscrollview
        if (!_scrollView) {
            _scrollView = [[UIScrollViewalloc]initWithFrame:self.bounds];
        }
        _scrollView.showsHorizontalScrollIndicator =NO;
        _scrollView.showsVerticalScrollIndicator =NO;
        _scrollView.pagingEnabled =YES;
        _scrollView.delegate =self;
        [self addSubview:_scrollView];
        
        _currentInt =0;   //首次加载后就进入首张图片  (0 1 2)
        //初始化当前页面三张图片的array
        if (!_currentArray) {
            _currentArray = [[NSMutableArrayalloc]initWithCapacity:3];
        }
        //初始化总的图片数组
        if (!_screenArray) {
            _screenArray = [[NSMutableArrayalloc]initWithCapacity:5];
        }
    }
    return self;
}

- (void)dealloc
{
    [_scrollView release];
    [_currentArray
release];
    [_screenArray release];
    [super dealloc];
}

#pragma mark -- 
#pragma mark Methods
- (void)refreshData:(NSMutableArray*)imagesArray
{
    if (!imagesArray || (imagesArray.count ==0))return;
    
    if (_screenArray &&_screenArray.count >0)
{
        [_screenArrayremoveAllObjects];
    }
    self.screenArray = imagesArray;
    _totalInt = self.screenArray.count;
    [selfrefreshDataForScrollviewDelegate];
}

//当UIScrollViewDelegate被调用时也会调用这个方法，不仅仅是上边那个函数会调用
- (void)refreshDataForScrollviewDelegate
{
    if (_scrollView &&_scrollView.subviews.count
>0) {
        for (UIView *viewin_scrollView.subviews) {
            [view removeFromSuperview];
        }
    }
    if (_currentArray &&_currentArray.count >0)
{
        [_currentArrayremoveAllObjects];
    }
    if (_totalInt ==1) {  //如果只返回包含一个值的数组，就不应该再让它左右滑动了  （这个地方应该也有改进的空间，如果只返回一张图的话可以直接让scrollview停止滚动应该就行，不需要再单独加入这个图片，以后有可能
试试）
        UIImageView *imgView = [[UIImageViewalloc]initWithFrame:self.bounds];
        imgView.image = [UIImageimageNamed:_screenArray[0]];
        _scrollView.contentSize =self.bounds.size;
        [_scrollView addSubview:imgView];
        [imgView release];
    } else {               
//返回两个及以上个值的数组时均可左右滑动
        _scrollView.contentSize =CGSizeMake(self.bounds.size.width
*3, self.bounds.size.height);
        NSInteger _previousInt = [selfavailablePicInt:_currentInt -1]; 
//前一张图片
        NSInteger _behindInt = [selfavailablePicInt:_currentInt +1];   
//后一张图片
        [_currentArray addObject:_screenArray[_previousInt]];
        [_currentArray
addObject:_screenArray[_currentInt]];
        [_currentArray addObject:_screenArray[_behindInt]];
        
        for (int i =0; i <3; i++) {
            UIImageView* imgView = [[UIImageViewalloc]initWithFrame:CGRectMake(self.bounds.size.width
* i, 0, self.bounds.size.width,self.bounds.size.height)];
            imgView.image = [UIImageimageNamed:_currentArray[i]];
            [_scrollView addSubview:imgView];
            [imgView release];
        }
        [_scrollViewsetContentOffset:CGPointMake(self.bounds.size.width,0)];
    }
}

//获取实际的图片值
- (NSInteger)availablePicInt:(NSInteger)curInt
{
    if (curInt < 0) {
        return _totalInt -1;
    }
    if (curInt == _totalInt) {
        return 0;
    }
    return curInt;
}

#pragma mark --
#pragma mark UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if (scrollView.contentOffset.x >=self.bounds.size.width *2)
{
        _currentInt = [selfavailablePicInt:_currentInt +1];
        [selfrefreshDataForScrollviewDelegate];
    } else if (scrollView.contentOffset.x <=0 ) {   
        _currentInt = [selfavailablePicInt:_currentInt -1];
        [selfrefreshDataForScrollviewDelegate];
    }
}
//看齐冀写的这个地方共用了三个uiscrollviewdelegate代理方法，个人实验后应该用不着那么多 ，只用上边一个即可实现要求
@end