UIScrollView+UIPageControl+NSTimer实现图片的自动滑动以及用户可手动切换，UIPageControl可点击

        研究了一整天的成果，也借鉴了网上的一些资料，参考了http://huluwa.me/blog/ios-uiscrollview-loop/.的思想.主要实现了以下功能：

     1.自动滑动图片，UIPageControl会随着图片滑动而改变；
     2.用户可以手动切换图片，左右切换均可，当用户手动滑动图片时，图片停止自动切换；
     3.实现了图片的循环播放；
     4.UIPageControl可点击从而实现向左或右滑动，当用户点击UIPageControl时，图片不再自动切换；

    直接上代码吧，不懂的后面还有工程和说明文档也一并附上(原来这个不能直接上传附件，要的就去资源页下载吧：http://download.csdn.net/detail/zhuiyi316/4434616)。

    首先是.h文件，注意自己将IBOutlet和IBAction与storyBoard中拖入的控件相关联，我用的XCode4.3.1.

    

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIScrollViewDelegate>
{
    NSMutableArray *imageArray;//存放图片
    NSTimer *myTimer;//定时器
    
}
@property(nonatomic,retain) IBOutlet UIScrollView *myScrollView;
@property(nonatomic,retain) IBOutlet
    UIPageControl *pageControl;

-(IBAction)pageTurn:(UIPageControl *)sender;
@end

   然后是.m文件，自己添加图片。 #import <QuartzCore/QuartzCore.h>是用来设置边角的。

#import "ViewController.h"
#import <QuartzCore/QuartzCore.h>
@interface ViewController ()

@end

@implementation ViewController
@synthesize myScrollView,pageControl;

-(void)initArray
{
    imageArray=[NSArray arrayWithObjects: [UIImage imageNamed:@"share.png"],[UIImage imageNamed:@"home_baike.png"],[UIImage imageNamed:@"home_chat.png"],[UIImage imageNamed:@"Icon.png"],nil];
    //存放图片的数组

}
- (void)viewDidLoad
{
    [super viewDidLoad];
    [self initArray];
    [self configScrollView];  
   }
-(void)configScrollView
{
    /*
     @//初始化UIScrollView，设置相关属性，均可在storyBoard中设置
     CGRect frame=CGRectMake(0, 0, 320, 480);
     self.myScrollView = [[UIScrollView alloc]initWithFrame:frame];    //scrollView的大小
     self.myScrollView.backgroundColor=[UIColor blueColor];
     self.myScrollView.pagingEnabled=YES;//以页为单位滑动，即自动到下一页的开始边界
     self.myScrollView.showsVerticalScrollIndicator=NO;
     self.myScrollView.showsHorizontalScrollIndicator=NO;//隐藏垂直和水平显示条
     */  
    self.myScrollView.delegate=self;
    UIImageView *firstView=[[UIImageView alloc] initWithImage:[imageArray lastObject]];
    CGFloat Width=self.myScrollView.frame.size.width;
    CGFloat Height=self.myScrollView.frame.size.height;
    firstView.frame=CGRectMake(0, 0, Width, Height);
    [self.myScrollView addSubview:firstView];
    //set the last as the first
    
    for (int i=0; i<[imageArray count]; i++) {
        UIImageView *subViews=[[UIImageView alloc] initWithImage:[imageArray objectAtIndex:i]];
        subViews.frame=CGRectMake(Width*(i+1), 0, Width, Height);
        [self.myScrollView addSubview: subViews];
    }
    
    UIImageView *lastView=[[UIImageView alloc] initWithImage:[imageArray objectAtIndex:0]];
    lastView.frame=CGRectMake(Width*(imageArray.count+1), 0, Width, Height);
    [self.myScrollView addSubview:lastView];
    //set the first as the last
    
    [self.myScrollView setContentSize:CGSizeMake(Width*(imageArray.count+2), Height)];
    [self.view addSubview:self.myScrollView];
    [self.myScrollView scrollRectToVisible:CGRectMake(Width, 0, Width, Height) animated:NO];
    //show the real first image,not the first in the scrollView
    
/* 
@//设置pageControl的位置，及相关属性，可选
   CGRect pageControlFrame=CGRectMake(100, 160, 78, 36);
   self.pageControl=[[UIPageControl alloc]initWithFrame:pageControlFrame];
    
    [self.pageControl setBounds:CGRectMake(0, 0, 16*(self.pageControl.numberOfPages-1), 16)];//设置pageControl中点的间距为16
    [self.pageControl.layer setCornerRadius:8];//设置圆角
*/
    self.pageControl.numberOfPages=imageArray.count; 
//    self.pageControl.backgroundColor=[UIColor blueColor];//背景
    self.pageControl.currentPage=0;
    self.pageControl.enabled=YES;
    [self.view addSubview:self.pageControl];
    [self.pageControl addTarget:self action:@selector(pageTurn:)forControlEvents:UIControlEventValueChanged];
    
    myTimer=[NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector:@selector(scrollToNextPage:) userInfo:nil repeats:YES];
    
}

#pragma UIScrollView delegate
-(void)scrollToNextPage:(id)sender
{
    int pageNum=self.pageControl.currentPage;
    CGSize viewSize=self.myScrollView.frame.size;
    CGRect rect=CGRectMake((pageNum+2)*viewSize.width, 0, viewSize.width, viewSize.height);
    [self.myScrollView scrollRectToVisible:rect animated:NO];
    pageNum++;
    if (pageNum==imageArray.count) {
        CGRect newRect=CGRectMake(viewSize.width, 0, viewSize.width, viewSize.height);
        [self.myScrollView scrollRectToVisible:newRect animated:NO];
    }
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat pageWidth=self.myScrollView.frame.size.width; 
    int currentPage=floor((self.myScrollView.contentOffset.x-pageWidth/2)/pageWidth)+1;
    if (currentPage==0) {
        self.pageControl.currentPage=imageArray.count-1;
    }else if(currentPage==imageArray.count+1){
        self.pageControl.currentPage=0;
    }
    self.pageControl.currentPage=currentPage-1;
    
}
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    [myTimer invalidate];
}
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    myTimer=[NSTimer scheduledTimerWithTimeInterval:2.0f target:self selector:@selector(scrollToNextPage:) userInfo:nil repeats:YES];
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    CGFloat pageWidth=self.myScrollView.frame.size.width;
    CGFloat pageHeigth=self.myScrollView.frame.size.height;
    int currentPage=floor((self.myScrollView.contentOffset.x-pageWidth/2)/pageWidth)+1;
    NSLog(@"the current offset==%f",self.myScrollView.contentOffset.x);
    NSLog(@"the current page==%d",currentPage);
    
    if (currentPage==0) {
        [self.myScrollView scrollRectToVisible:CGRectMake(pageWidth*imageArray.count, 0, pageWidth, pageHeigth) animated:NO];
        self.pageControl.currentPage=imageArray.count-1;
        NSLog(@"pageControl currentPage==%d",self.pageControl.currentPage);
        NSLog(@"the last image");
        return;
    }else  if(currentPage==[imageArray count]+1){
        [self.myScrollView scrollRectToVisible:CGRectMake(pageWidth, 0, pageWidth, pageHeigth) animated:NO];
        self.pageControl.currentPage=0;
        NSLog(@"pageControl currentPage==%d",self.pageControl.currentPage);
        NSLog(@"the first image");
        return;
    }
    self.pageControl.currentPage=currentPage-1;
    NSLog(@"pageControl currentPage==%d",self.pageControl.currentPage);
    
}
-(IBAction)pageTurn:(UIPageControl *)sender
{
    int pageNum=pageControl.currentPage;
    CGSize viewSize=self.myScrollView.frame.size;
    [self.myScrollView setContentOffset:CGPointMake((pageNum+1)*viewSize.width, 0)];
    NSLog(@"myscrollView.contentOffSet.x==%f",myScrollView.contentOffset.x);
    NSLog(@"pageControl currentPage==%d",self.pageControl.currentPage);   [myTimer invalidate];
}

@end

       还存在的问题：当我点击UIPageControl中的白点时一次只能切换一张图片，即不能精确定位到某一个点所对应的图片，上网查了好多资料，都没有那个解决。貌似那样是不可以的， http://stackoverflow.com/questions/1103915/is-uipagecontrol-useless-by-itself和 http://stackoverflow.com/questions/4037416/scrollview-pagecontrol-dot-doesnt-change-with-the-page?rq=1中有相关的讨论。希望各位牛人能帮忙解决一下这个问题。ps：stackoverflow.com是一个很牛气的网站，我的很多问题都是在这里找到解决办法的，这是一个英文网站，有时看着会比较吃力。努力学习英语啊， ，与各位同仁共勉。