iOS开发中使用UIScrollView实现无限循环的图片浏览器

typedef NS_OPTIONS(NSUInteger, UIViewAutoresizing) {
 UIViewAutoresizingNone   = 0, //不进行自动调整
 UIViewAutoresizingFlexibleLeftMargin = 1 << 0, //自动调整与superview左侧距离，右侧距离保持不变
 UIViewAutoresizingFlexibleWidth = 1 << 1, //自动调整控件自身宽度，保证与superview左右距离不变
 UIViewAutoresizingFlexibleRightMargin = 1 << 2, //自动调整与superview右侧距离，左侧距离保持不变
 UIViewAutoresizingFlexibleTopMargin = 1 << 3, //自动调整与superview顶部距离，底部距离保持不变
 UIViewAutoresizingFlexibleHeight = 1 << 4, //自动调整控件自身高度，保证与superview上下距离不变
 UIViewAutoresizingFlexibleBottomMargin = 1 << 5 //自动调整与superview底部距离，顶部距离保持不变
};

//
// AppDelegate.m
// UIViewAndUIScrollView
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "AppDelegate.h"
#import "KCMainViewController.h"
#import "KCTransformViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate
  

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
 
 self.window=[[UIWindow alloc]initWithFrame:[UIScreen mainScreen].applicationFrame];
 
 KCMainViewController *mainController=[[KCMainViewController alloc]init];
 self.window.rootViewController=mainController;
 self.window.backgroundColor=[UIColor colorWithRed:249/255.0 green:249/255.0 blue:249/255.0 alpha:1];

 [self.window makeKeyAndVisible];
 
 return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application {
 // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
 // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
 // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
 // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
 // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
 // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

- (void)applicationWillTerminate:(UIApplication *)application {
 // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

@end

//
// KCMainViewController.m
// UIViewAndUIScrollView
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "KCMainViewController.h"

@interface KCMainViewController (){
 UIButton *_btn; //私有变量
}

@end

@implementation KCMainViewController

- (void)viewDidLoad {
 [super viewDidLoad];
 
 //添加一个Button
 _btn=[[UIButton alloc]initWithFrame:CGRectMake(60, 100, 200, 50)];
 _btn.backgroundColor=[UIColor orangeColor];
 [_btn setTitle:@"Hello,world!" forState:UIControlStateNormal];
 _btn.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleLeftMargin;
 [self.view addSubview:_btn];
 
}

#pragma mark 屏幕旋转事件
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
 NSLog(@"%@",NSStringFromCGRect(_btn.frame));
}
@end

//
// KCTransformViewController.m
// UIViewAndUIScrollView
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "KCTransformViewController.h"
//定义rgb颜色
#define NORMAL_COLOR [UIColor colorWithRed:75/255.0 green:160/255.0 blue:253/255.0 alpha:1]
#define HIGHLIGHTED_COLOR [UIColor colorWithRed:197/255.0 green:221/225.0 blue:249/225.0 alpha:1]
//按钮操作
typedef void(^ ButtonHandle)();

@interface KCTransformViewController (){
 UIImageView *_imageView;//图片控件
 UIButton *_btnRotation;//旋转按钮
 UIButton *_btnScale;//缩放按钮
 UIButton *_btnTranslate;//移动按钮
}

@end

@implementation KCTransformViewController

- (void)viewDidLoad {
 [super viewDidLoad];
 
 [self addImageView];
 [self addRotationButton];
 [self addScaleButton];
 [self addTranslateButton];
 
}

#pragma mark 添加图片控件
-(void)addImageView{
 //直接使用图片名称，系统会自动到资源文件中找到对应的文件
 UIImage *image=[UIImage imageNamed:@"promo_ios8.png"];
 //如果使用initWithImage进行初始化则控件大小会自动设置成图片大小
 _imageView=[[UIImageView alloc]initWithImage:image];
 _imageView.frame=CGRectMake(20, 20, 280, 154);
 //设置内容填充模式为等比例填充
 _imageView.contentMode=UIViewContentModeScaleAspectFit;
 //self.view就是每个视图控制器中的view属性
 [self.view addSubview:_imageView];
}

#pragma mark 添加旋转按钮
-(void)addRotationButton{
 _btnRotation=[self getButton];
 _btnRotation.frame=CGRectMake(20, 400, 280, 30);
 [_btnRotation setTitle:@"旋转" forState:UIControlStateNormal];
 //添加按钮点击事件
 [_btnRotation addTarget:self action:@selector(rotation:) forControlEvents:UIControlEventTouchUpInside];
 [self.view addSubview:_btnRotation];
}

#pragma mark 添加缩放按钮
-(void)addScaleButton{
 //在上面一个按钮位置的基础上确认当前位置
 CGRect scaleButtonFrame=_btnRotation.frame;
 scaleButtonFrame.origin.y+=40;
 _btnScale =[self getButton];
 _btnScale.frame=scaleButtonFrame;
 [_btnScale setTitle:@"缩放" forState:UIControlStateNormal];
 //添加按钮点击事件
 [_btnScale addTarget:self action:@selector(scale:) forControlEvents:UIControlEventTouchUpInside];
 [self.view addSubview:_btnScale];
}

#pragma mark 添加移动按钮
-(void)addTranslateButton{
 CGRect translateButtonFrame=_btnScale.frame;
 translateButtonFrame.origin.y+=40;
 _btnTranslate =[self getButton];
 _btnTranslate.frame=translateButtonFrame;
 [_btnTranslate setTitle:@"移动" forState:UIControlStateNormal];
 [_btnTranslate addTarget:self action:@selector(translate:) forControlEvents:UIControlEventTouchUpInside];
 [self.view addSubview:_btnTranslate];
 
}

#pragma mark 图片旋转方法,注意参数中的btn表示当前点击按钮
-(void)rotation:(UIButton *)btn{
 [self animation:^{
 //注意旋转角度必须是弧度，不是角度
 CGFloat angle=M_PI_4;//M开头的宏都是和数学（Math）相关的宏定义，M_PI_4表示四分之派，M_2_PI表示2派
 //使用CGAffineTransformMakeRotation获得一个旋转角度形变
 //但是需要注意tranform的旋转不会自动在原来的角度上进行叠加，所以下面的方法旋转一次以后再点击按钮不会旋转了
 //_imageView.transform=CGAffineTransformMakeRotation(angle);
 //利用CGAffineTransformRotate在原来的基础上产生一个新的角度(当然也可以定义一个全局变量自己累加)
 _imageView.transform=CGAffineTransformRotate(_imageView.transform, angle);
 
 }];
}

#pragma mark 图片缩放方法
-(void)scale:(UIButton *)btn{
// [self animation:^{
// CGFloat scalleOffset=0.9;
// //_imageView.transform=CGAffineTransformMakeScale(scalleOffset, scalleOffset);
// _imageView.transform= CGAffineTransformScale(_imageView.transform, scalleOffset, scalleOffset);
// }];
 //通常我们使用UIView的静态方法实现动画而不是自己写一个方法
 [UIView animateWithDuration:0.5 animations:^{
 CGFloat scalleOffset=0.9;
 //_imageView.transform=CGAffineTransformMakeScale(scalleOffset, scalleOffset);
 _imageView.transform= CGAffineTransformScale(_imageView.transform, scalleOffset, scalleOffset);
 }];
}

#pragma mark 图片移动方法
-(void)translate:(UIButton *)btn{
 [self animation:^{
 CGFloat translateY=50;
 //_imageView.transform=CGAffineTransformMakeTranslation(0, translateY);
 _imageView.transform=CGAffineTransformTranslate(_imageView.transform, 0, translateY);
 }];
}

#pragma mark 动画执行方法，注意这里可以使用UIView的animateWithDuration方法代替这里只是为了演示
-(void)animation:(ButtonHandle)handle{
 //开始动画
 [UIView beginAnimations:@"animation" context:nil];
 //设置动画执行时间
 [UIView setAnimationDuration:0.5];
 
 handle();
 
 //执行动画操作
 [UIView commitAnimations];
 
}

#pragma mark 取得一个按钮,统一按钮样式
-(UIButton *)getButton{
 UIButton *button =[[UIButton alloc]init ];
 //设置正常状态下字体颜色
 [button setTitleColor:NORMAL_COLOR forState:UIControlStateNormal];
 //设置高亮状态下的字体颜色
 [button setTitleColor:HIGHLIGHTED_COLOR forState:UIControlStateHighlighted];
 return button;
}

@end

//
// KCScrollViewController.h
// UIViewAndUIScrollView
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface KCScrollViewController : UIViewController

@property (nonatomic,strong) UIScrollView *scrollView;

@property (nonatomic,strong) UIImageView *imageView;

@end

//
// KCScrollViewController.m
// UIViewAndUIScrollView
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "KCScrollViewController.h"

//实现UIScrollView代理
@interface KCScrollViewController ()<UIScrollViewDelegate>

@end

@implementation KCScrollViewController

- (void)viewDidLoad {
 [super viewDidLoad];
 
 //添加scrollView控件
 //注意UIScreen代表当前屏幕对象，其applicationFrame是当前屏幕内容区域
 _scrollView =[[UIScrollView alloc]initWithFrame:[UIScreen mainScreen].applicationFrame];
 //_scrollView.backgroundColor=[UIColor redColor];
 _scrollView.contentMode=UIViewContentModeScaleToFill;
 [self.view addSubview:_scrollView];
 
 
 //添加图片控件
 UIImage *image=[UIImage imageNamed:@"wwdc14-labs-hero-background.jpg"];
 _imageView=[[UIImageView alloc]initWithImage:image];
 [_scrollView addSubview:_imageView];
 
 
 
 //contentSize必须设置,否则无法滚动，当前设置为图片大小
 _scrollView.contentSize=_imageView.frame.size;
 
 //实现缩放：maxinumZoomScale必须大于minimumZoomScale同时实现viewForZoomingInScrollView方法
 _scrollView.minimumZoomScale=0.6;
 _scrollView.maximumZoomScale=3.0;
 //设置代理
 _scrollView.delegate=self;
 

 //边距，不属于内容部分，内容坐标（0，0）指的是内容的左上角不包括边界
 //_scrollView.contentInset=UIEdgeInsetsMake(10, 20, 10, 20);
 
 //显示滚动内容的指定位置
 //_scrollView.contentOffset=CGPointMake(10, 0);
 
 //隐藏滚动条
 _scrollView.showsHorizontalScrollIndicator=NO;
 _scrollView.showsVerticalScrollIndicator=NO;
 
 //禁用弹簧效果
 //_scrollView.bounces=NO;
}

#pragma mark 实现缩放视图代理方法，不实现此方法无法缩放
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
 return _imageView;
}
-(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{
 NSLog(@"scrollViewWillBeginDecelerating");
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
 NSLog(@"scrollViewDidEndDecelerating");
}
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
 NSLog(@"scrollViewWillBeginDragging");
}
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
 NSLog(@"scrollViewDidEndDragging");
}
-(void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view{
 NSLog(@"scrollViewWillBeginZooming");
}
-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
 NSLog(@"scrollViewDidEndZooming");
}
//-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
// NSLog(@"scrollViewDidScroll");
//}

#pragma mark 当图片小于屏幕宽高时缩放后让图片显示到屏幕中间
-(void)scrollViewDidZoom:(UIScrollView *)scrollView{
 CGSize originalSize=_scrollView.bounds.size;
 CGSize contentSize=_scrollView.contentSize;
 CGFloat offsetX=originalSize.width>contentSize.width?(originalSize.width-contentSize.width)/2:0;
 CGFloat offsetY=originalSize.height>contentSize.height?(originalSize.height-contentSize.height)/2:0;

 _imageView.center=CGPointMake(contentSize.width/2+offsetX, contentSize.height/2+offsetY);
}

@end

//
// KCPerson.h
// ARC
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface KCPerson : NSObject

@property (nonatomic,assign) int no;

@end

//
// KCPerson.m
// ARC
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "KCPerson.h"

@implementation KCPerson

-(NSString *)description{
 return [NSString stringWithFormat:@"no=%i",_no];
}

@end

//
// main.m
// ARC
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "KCPerson.h"

int main(int argc, const char * argv[]) {
 @autoreleasepool {
 
 //strong
 __strong KCPerson *person1=[[KCPerson alloc]init];
 __strong KCPerson *person2=person1;
 person1.no=1;
 NSLog(@"%@",person2); //结果：no=1
 person1=nil;
 NSLog(@"%@",person2); //结果：no=1
 
 
 //weak
 __strong KCPerson *person3=[[KCPerson alloc]init];
 __weak KCPerson *person4=person3;
 person3.no=3;
 NSLog(@"%@",person4); //结果：no=3
 person3=nil;
 NSLog(@"%@",person4); //结果：(null)

 }
 return 0;
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
 <key>0.jpg</key>
 <string>iphone 5s</string>
 <key>1.jpg</key>
 <string>iphone 5c</string>
 <key>2.jpg</key>
 <string>ipad min with retain</string>
 <key>3.jpg</key>
 <string>ipad air</string>
 <key>4.jpg</key>
 <string>ipod</string>
 <key>5.jpg</key>
 <string>ipod touch</string>
 <key>6.jpg</key>
 <string>mac book pro</string>
 <key>7.jpg</key>
 <string>mac book air</string>
 <key>8.jpg</key>
 <string>imac</string>
</dict>
</plist>

//
// KCMainViewController.m
// ImageViewer
//
// Created by Kenshin Cui on 14-2-23.
// Copyright (c) 2014年 Kenshin Cui. All rights reserved.
//

#import "KCMainViewController.h"
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 568
#define IMAGEVIEW_COUNT 3

@interface KCMainViewController ()<UIScrollViewDelegate>{
 UIScrollView *_scrollView;
 UIImageView *_leftImageView;
 UIImageView *_centerImageView;
 UIImageView *_rightImageView;
 UIPageControl *_pageControl;
 UILabel *_label;
 NSMutableDictionary *_imageData;//图片数据
 int _currentImageIndex;//当前图片索引
 int _imageCount;//图片总数
}

@end

@implementation KCMainViewController

- (void)viewDidLoad {
 [super viewDidLoad];
 //加载数据
 [self loadImageData];
 //添加滚动控件
 [self addScrollView];
 //添加图片控件
 [self addImageViews];
 //添加分页控件
 [self addPageControl];
 //添加图片信息描述控件
 [self addLabel];
 //加载默认图片
 [self setDefaultImage];
}

#pragma mark 加载图片数据
-(void)loadImageData{
 //读取程序包路径中的资源文件
 NSString *path=[[NSBundle mainBundle] pathForResource:@"imageInfo" ofType:@"plist"];
 _imageData=[NSMutableDictionary dictionaryWithContentsOfFile:path];
 _imageCount=(int)_imageData.count;
}

#pragma mark 添加控件
-(void)addScrollView{
 _scrollView=[[UIScrollView alloc]initWithFrame:[UIScreen mainScreen].bounds];
 [self.view addSubview:_scrollView];
 //设置代理
 _scrollView.delegate=self;
 //设置contentSize
 _scrollView.contentSize=CGSizeMake(IMAGEVIEW_COUNT*SCREEN_WIDTH, SCREEN_HEIGHT) ;
 //设置当前显示的位置为中间图片
 [_scrollView setContentOffset:CGPointMake(SCREEN_WIDTH, 0) animated:NO];
 //设置分页
 _scrollView.pagingEnabled=YES;
 //去掉滚动条
 _scrollView.showsHorizontalScrollIndicator=NO;
}

#pragma mark 添加图片三个控件
-(void)addImageViews{
 _leftImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];
 _leftImageView.contentMode=UIViewContentModeScaleAspectFit;
 [_scrollView addSubview:_leftImageView];
 _centerImageView=[[UIImageView alloc]initWithFrame:CGRectMake(SCREEN_WIDTH, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];
 _centerImageView.contentMode=UIViewContentModeScaleAspectFit;
 [_scrollView addSubview:_centerImageView];
 _rightImageView=[[UIImageView alloc]initWithFrame:CGRectMake(2*SCREEN_WIDTH, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];
 _rightImageView.contentMode=UIViewContentModeScaleAspectFit;
 [_scrollView addSubview:_rightImageView];

}
#pragma mark 设置默认显示图片
-(void)setDefaultImage{
 //加载默认图片
 _leftImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",_imageCount-1]];
 _centerImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",0]];
 _rightImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",1]];
 _currentImageIndex=0;
 //设置当前页
 _pageControl.currentPage=_currentImageIndex;
 NSString *imageName=[NSString stringWithFormat:@"%i.jpg",_currentImageIndex];
 _label.text=_imageData[imageName];
}

#pragma mark 添加分页控件
-(void)addPageControl{
 _pageControl=[[UIPageControl alloc]init];
 //注意此方法可以根据页数返回UIPageControl合适的大小
 CGSize size= [_pageControl sizeForNumberOfPages:_imageCount];
 _pageControl.bounds=CGRectMake(0, 0, size.width, size.height);
 _pageControl.center=CGPointMake(SCREEN_WIDTH/2, SCREEN_HEIGHT-100);
 //设置颜色
 _pageControl.pageIndicatorTintColor=[UIColor colorWithRed:193/255.0 green:219/255.0 blue:249/255.0 alpha:1];
 //设置当前页颜色
 _pageControl.currentPageIndicatorTintColor=[UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];
 //设置总页数
 _pageControl.numberOfPages=_imageCount;
 
 [self.view addSubview:_pageControl];
}

#pragma mark 添加信息描述控件
-(void)addLabel{
 
 _label=[[UILabel alloc]initWithFrame:CGRectMake(0, 10, SCREEN_WIDTH,30)];
 _label.textAlignment=NSTextAlignmentCenter;
 _label.textColor=[UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];

 [self.view addSubview:_label];
}

#pragma mark 滚动停止事件
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
 //重新加载图片
 [self reloadImage];
 //移动到中间
 [_scrollView setContentOffset:CGPointMake(SCREEN_WIDTH, 0) animated:NO];
 //设置分页
 _pageControl.currentPage=_currentImageIndex;
 //设置描述
 NSString *imageName=[NSString stringWithFormat:@"%i.jpg",_currentImageIndex];
 _label.text=_imageData[imageName];
}

#pragma mark 重新加载图片
-(void)reloadImage{
 int leftImageIndex,rightImageIndex;
 CGPoint offset=[_scrollView contentOffset];
 if (offset.x>SCREEN_WIDTH) { //向右滑动
  _currentImageIndex=(_currentImageIndex+1)%_imageCount;
 }else if(offset.x<SCREEN_WIDTH){ //向左滑动
  _currentImageIndex=(_currentImageIndex+_imageCount-1)%_imageCount;
 }
 //UIImageView *centerImageView=(UIImageView *)[_scrollView viewWithTag:2];
 _centerImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",_currentImageIndex]];
 
 //重新设置左右图片
 leftImageIndex=(_currentImageIndex+_imageCount-1)%_imageCount;
 rightImageIndex=(_currentImageIndex+1)%_imageCount;
 _leftImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",leftImageIndex]];
 _rightImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"%i.jpg",rightImageIndex]];
}

@end