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