如何使用 UIPageViewController 加载单独的 XIB？

Question

我正在深入研究 UIPageViewControllers 的新世界，那里有很多教程，但是它们似乎都创建了一个视图，然后只使用具有不同内容的新实例。

我真的很希望能够创建多个 XIB，然后将它们与 UIPageViewController 链接在一起，但它太新了，我无法理解它的工作方式。

Answer 1

嗯，这是一个很长的答案，您应该可以复制和粘贴。 （此代码改编自 Erica Sadun (https://github.com/erica/iOS-5-Cookbook)）

首先，创建一个 UIPageViewController 类型的新类。称它为 BookController。现在将以下代码粘贴到您的 .h 文件中。

// Used for storing the most recent book page used
#define DEFAULTS_BOOKPAGE   @"BookControllerMostRecentPage"

@protocol BookControllerDelegate <NSObject>
- (id) viewControllerForPage: (int) pageNumber;
@optional
- (void) bookControllerDidTurnToPage: (NSNumber *) pageNumber;
@end

@interface BookController : UIPageViewController <UIPageViewControllerDelegate, UIPageViewControllerDataSource>
+ (id) bookWithDelegate: (id) theDelegate;
+ (id) rotatableViewController;
- (void) moveToPage: (uint) requestedPage;
- (int) currentPage;

@property (assign) id <BookControllerDelegate> bookDelegate;
@property (nonatomic, assign) uint pageNumber;

在您的 .m 文件中：

#define IS_IPHONE   ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
#define SAFE_ADD(_Array_, _Object_) {if (_Object_ && [_Array_ isKindOfClass:[NSMutableArray class]]) [pageControllers addObject:_Object_];}
#define SAFE_PERFORM_WITH_ARG(THE_OBJECT, THE_SELECTOR, THE_ARG) (([THE_OBJECT respondsToSelector:THE_SELECTOR]) ? [THE_OBJECT performSelector:THE_SELECTOR withObject:THE_ARG] : nil)


#pragma Utility Class - VC that Rotates
@interface RotatableVC : UIViewController 
@end
@implementation RotatableVC
- (void) loadView 
{
    [super loadView]; 
    self.view.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    self.view.backgroundColor = [UIColor whiteColor];
}
- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation 
{
    return YES;
}
@end


#pragma Book Controller
@implementation BookController
@synthesize bookDelegate, pageNumber;

#pragma mark Debug / Utility
- (int) currentPage
{
    int pageCheck = ((UIViewController *)[self.viewControllers objectAtIndex:0]).view.tag;
    return pageCheck;
}

#pragma mark Page Handling

// Update if you'd rather use some other decision style
- (BOOL) useSideBySide: (UIInterfaceOrientation) orientation
{
    BOOL isLandscape = UIInterfaceOrientationIsLandscape(orientation);
    return isLandscape;
}

// Store the new page and update the delegate
- (void) updatePageTo: (uint) newPageNumber
{   
    pageNumber = newPageNumber;

    [[NSUserDefaults standardUserDefaults] setInteger:pageNumber forKey:DEFAULTS_BOOKPAGE];
    [[NSUserDefaults standardUserDefaults] synchronize];

    SAFE_PERFORM_WITH_ARG(bookDelegate, @selector(bookControllerDidTurnToPage:), [NSNumber numberWithInt:pageNumber]);

}

// Request controller from delegate
- (UIViewController *) controllerAtPage: (int) aPageNumber
{
    if (bookDelegate && 
        [bookDelegate respondsToSelector:@selector(viewControllerForPage:)])
    {
        UIViewController *controller = [bookDelegate viewControllerForPage:aPageNumber];
        controller.view.tag = aPageNumber;
        return controller;
    }
    return nil;
}

// Update interface to the given page
- (void) fetchControllersForPage: (uint) requestedPage orientation: (UIInterfaceOrientation) orientation
{
    BOOL sideBySide = [self useSideBySide:orientation];
    int numberOfPagesNeeded = sideBySide ? 2 : 1;
    int currentCount = self.viewControllers.count;

    uint leftPage = requestedPage;
    if (sideBySide && (leftPage % 2)) leftPage--;

    // Only check against current page when count is appropriate
    if (currentCount && (currentCount == numberOfPagesNeeded))
    {
        if (pageNumber == requestedPage) return;
        if (pageNumber == leftPage) return;
    }

    // Decide the prevailing direction by checking the new page against the old
    UIPageViewControllerNavigationDirection direction = (requestedPage > pageNumber) ? UIPageViewControllerNavigationDirectionForward : UIPageViewControllerNavigationDirectionReverse;
    [self updatePageTo:requestedPage];

    // Update the controllers
    NSMutableArray *pageControllers = [NSMutableArray array];
    SAFE_ADD(pageControllers, [self controllerAtPage:leftPage]);    
    if (sideBySide)
        SAFE_ADD(pageControllers, [self controllerAtPage:leftPage + 1]);

    [self setViewControllers:pageControllers direction: direction animated:YES completion:nil];
}

// Entry point for external move request
- (void) moveToPage: (uint) requestedPage
{
    [self fetchControllersForPage:requestedPage orientation:(UIInterfaceOrientation)[UIDevice currentDevice].orientation];
}

#pragma mark Data Source

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
    [self updatePageTo:pageNumber + 1];
    return [self controllerAtPage:(viewController.view.tag + 1)];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    [self updatePageTo:pageNumber - 1];
    return [self controllerAtPage:(viewController.view.tag - 1)];
}

#pragma mark Delegate

- (UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
{
    NSUInteger indexOfCurrentViewController = 0;
    if (self.viewControllers.count)
        indexOfCurrentViewController = ((UIViewController *)[self.viewControllers objectAtIndex:0]).view.tag;
    [self fetchControllersForPage:indexOfCurrentViewController orientation:orientation];

    BOOL sideBySide = [self useSideBySide:orientation];
    self.doubleSided = sideBySide;

    UIPageViewControllerSpineLocation spineLocation = sideBySide ? UIPageViewControllerSpineLocationMid : UIPageViewControllerSpineLocationMin;
    return spineLocation;
}

-(void)dealloc{
    self.bookDelegate = nil;
}

#pragma mark Class utility routines
// Return a UIViewController that knows how to rotate
+ (id) rotatableViewController
{
    UIViewController *vc = [[RotatableVC alloc] init];
    return vc;
}

// Return a new book
+ (id) bookWithDelegate: (id) theDelegate
{
    BookController *bc = [[BookController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];

    bc.dataSource = bc;
    bc.delegate = bc;
    bc.bookDelegate = theDelegate;

    return bc;
}

这个类现在可用于控制您在任何项目中创建的任何书籍，以及单个项目中的多本书。对于每本书，使用@interface 创建一个委托 UIPageViewController：

@interface NameOfBookController : UIPageViewController <BookControllerDelegate>

在这个委托的 .m 文件中，包含：

// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{
    [super loadView];
    CGRect appRect = [[UIScreen mainScreen] applicationFrame];
    self.view = [[UIView alloc] initWithFrame: appRect];
    self.view.backgroundColor = [UIColor whiteColor];
    self.view.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;

    // Establish the page view controller
    bookController = [BookController bookWithDelegate:self];
    bookController.view.frame = (CGRect){.size = appRect.size};
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
    // Add the child controller, and set it to the first page
    [self.view addSubview:bookController.view];
    [self addChildViewController:bookController];
    [bookController didMoveToParentViewController:self];
}

然后添加：

- (id) viewControllerForPage: (int) pageNumber
{    

    // Establish a new controller

    UIViewController *controller;


    switch (pageNumber) {
        case 0:
            view1 = [[FirstViewController alloc] init];
            view1.view.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
            controller = view1;
//rinse and repeat with each new view controller
            break;
        case 1:
            //etc.
            break;
        default:
            return nil;
            break;
    }
    return controller;
}

郑重声明，此代码不是内存安全的。如果使用 ARC，请添加您的 @autoreleasePool{};如果没有，请不要忘记您的保留/释放周期。

我希望这会有所帮助！

Answer 2

本文展示了如何使用 UIPageViewController 为每个页面创建一个带有自定义视图控制器的应用程序：http://www.informit.com/articles/article.aspx?p=1760500&seqNum=6