一、UIPageViewController概念
控件为我们提供了一种像翻书效果的一种控件。我们可以通过使用UIPageViewController控件,来完成类似图书一样的翻页控制方式。
二、使用UIPageViewController控件
先假象一下,一本书大概可以分为:1.每一页。2.每一页中相应的数据。
使用UIPageViewController控件,也是类似的两个构成部分。要有一个书的框架,来控制页;每一页的内容。
1.创建一个ViewController,包含一个UIPageViewController来控制显示,一个NSArray包括所有数据。
定义这个ViewController类,并使用UIPageViewController来管理每一页,并提供数据。
PageAppViewController.h
@interface PageAppViewController :UIViewController<</span>UIPageViewControllerDataSource>{
}
@property (strong, nonatomic) UIPageViewController *pageController;
@property (strong, nonatomic) NSArray *pageContent;
@end
PageAppViewController.m
#import"PageAppViewController.h"
#import"MoreViewController.h"
@interfacePageAppViewController ()
@end
@implementationPageAppViewController
@synthesizepageContent=_pageContent;
@synthesizepageController=_pageController;
-(void)dealloc{
[_pageContent release];
[_pageController release];
[super dealloc];
}
-(id)initWithNibName:(NSString *)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custominitialization
}
return self;
}
-(void)viewDidLoad
{
[superviewDidLoad];
[self createContentPages];//初始化所有数据
// 设置UIPageViewController的配置项
NSDictionary *options =[NSDictionarydictionaryWithObject:[NSNumber numberWithInteger:UIPageViewControllerSpineLocationMin]
forKey:UIPageViewControllerOptionSpineLocationKey];
// 实例化UIPageViewController对象,根据给定的属性
self.pageController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options: options];
// 设置UIPageViewController对象的代理
_pageController.dataSource = self;
// 定义“这本书”的尺寸
[[_pageControllerview] setFrame:[[selfview] bounds]];
// 让UIPageViewController对象,显示相应的页数据。
// UIPageViewController对象要显示的页数据封装成为一个NSArray。
// 因为我们定义UIPageViewController对象显示样式为显示一页(options参数指定)。
//如果要显示2页,NSArray中,应该有2个相应页数据。
MoreViewController *initialViewController=[self viewControllerAtIndex:0];//得到第一页
NSArray *viewControllers =[NSArray arrayWithObject:initialViewController];
[_pageController setViewControllers:viewControllers
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
// 在页面上,显示UIPageViewController对象的View
[selfaddChildViewController:_pageController];
[[self view] addSubview:[_pageController view]];
}
//初始化所有数据
-(void) createContentPages {
NSMutableArray *pageStrings = [[NSMutableArrayalloc] init];
for (int i = 1; i < 11; i++){
NSString *contentString = [[NSString alloc]initWithFormat:@"
Chapter %d
This is the page %d of content displayed usingUIPageViewController in iOS 5.
"
, i, i]; [pageStrings addObject:contentString];
}
self.pageContent = [[NSArray alloc] initWithArray:pageStrings];
}
-(void)didReceiveMemoryWarning
{
[superdidReceiveMemoryWarning];
// Dispose of any resources that can berecreaviewControllerAtIndexed.
}
//得到相应的VC对象
-(MoreViewController*)viewControllerAtIndex:(NSUInteger)index {
if (([self.pageContent count] == 0) || (index >= [self.pageContent count])) {
returnnil;
}
//创建一个新的控制器类,并且分配给相应的数据
MoreViewController *dataViewController =[[MoreViewControlleralloc] init];
dataViewController.dataObject=[self.pageContent objectAtIndex:index];
return dataViewController;
}
//根据数组元素值,得到下标值
-(NSUInteger)indexOfViewController:(MoreViewController*)viewController {
return [self.pageContent indexOfObject:viewController.dataObject];
}
#pragma mark- UIPageViewControllerDataSource
// 返回上一个ViewController对象
-(UIViewController*)pageViewController:(UIPageViewController *)pageViewControllerviewControllerBeforeViewController:(UIViewController *)viewController{
NSUInteger index = [self indexOfViewController:(MoreViewController *)viewController];
if ((index == 0) || (index == NSNotFound)) {
returnnil;
}
index--;
// 返回的ViewController,将被添加到相应的UIPageViewController对象上。
// UIPageViewController对象会根据UIPageViewControllerDataSource协议方法,自动来维护次序。
// 不用我们去操心每个ViewController的顺序问题。
return [selfviewControllerAtIndex:index];
}
// 返回下一个ViewController对象
-(UIViewController*)pageViewController:(UIPageViewController *)pageViewControllerviewControllerAfterViewController:(UIViewController *)viewController{
NSUInteger index = [self indexOfViewController:(MoreViewController *)viewController];
if (index == NSNotFound) {
returnnil;
}
index++;
if (index == [self.pageContent count]) {
returnnil;
}
return [selfviewControllerAtIndex:index];
}
@end
2.声明页对象,来根据UIPageViewController的调度来显示相应页内容。
#import
@interface MoreViewController :UIViewController<</span>UIWebViewDelegate>{
}
@property (nonatomic,retain) UIWebView *myWebView;
@property (nonatomic,retain) id dataObject;
@end
MoreViewController.m
#import"MoreViewController.h"
@implementationMoreViewController
@synthesizemyWebView=_myWebView;
@synthesizedataObject=_dataObject;
-(id)initWithNibName:(NSString *)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custominitialization
}
return self;
}
-(void)dealloc{
[_myWebView release];
[super dealloc];
}
-(void) loadView{
[super loadView];
self.myWebView =[[UIWebView alloc]initWithFrame:self.view.bounds];
}
-(void)viewDidLoad{
[superviewDidLoad];
}
-(void)viewWillAppear:(BOOL)paramAnimated{
[super viewWillAppear:paramAnimated];
[self.myWebView loadHTMLString:_dataObject baseURL:nil];
[self.view addSubview:self.myWebView];
}
-(void)viewWillDisappear:(BOOL)paramAnimated{
}
@end
三、总结
所有代码都已经写完了。其中也,写了相关的备注。
着重了解一下关键代码:
1.UIPageViewControllerDataSource协议
该协议主要有两个方法:
-(UIViewController*)pageViewController:(UIPageViewController *)pageViewControllerviewControllerBeforeViewController:(UIViewController *)viewController;
-(UIViewController*)pageViewController:(UIPageViewController *)pageViewControllerviewControllerAfterViewController:(UIViewController *)viewController;
分别,用来提供UIPageViewController对象的数据源。也就是说,UIPageViewController对象通过该方法来调度显示的内容。
当然,别忘了设置:
_pageController.dataSource = self;
你懂的!
2.初始化时,显示适当内容
MoreViewController *initialViewController=[self viewControllerAtIndex:0];// 得到第一页
NSArray *viewControllers=[NSArray arrayWithObject:initialViewController];
[_pageController setViewControllers:viewControllers
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
// 在页面上,显示UIPageViewController对象的View
[self addChildViewController:_pageController];
[[self view] addSubview:[_pageController view]];
3.数据必须先准备好。
[self createContentPages];//初始化所有数据
希望对你有所帮助!