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。