Question

我试图在代码中将UIPageViewController添加到我的RootViewController中。我按照删除了故事板文件 Xcode 5 without Storyboard and ARC 并添加“常规”ViewController完美地工作。我根据UIPageViewControllerDataSource

调整了方法

此外，我尝试简化逻辑（而不是从启动PageView项目实现ModelController我添加showVCWithIndex：方法从vcArray中选择3个VC中的1个并将其写入带有1个VC的Mutable Array。希望你能告诉我我是否正确或错了。

的.m

#import "RootPageViewController.h"
#import "ViewController0.h"
#import "ViewController1.h"
#import "ViewController2.h"

@interface RootPageViewController ()

@property (strong, nonatomic) ViewController0 *vController0;
@property (strong, nonatomic) ViewController1 *vController1;
@property (strong, nonatomic) ViewController2 *vController2;

@property (strong, nonatomic) UIPageViewController *pageViewController;

@property (strong, nonatomic) NSArray *vcArray;
@property (strong, nonatomic) NSMutableArray *viewController;

@end

@implementation RootPageViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];

    self.pageViewController.dataSource = self;

    _vController0 = [[ViewController0 alloc] init];
    _vController1 = [[ViewController1 alloc] init];
    _vController2 = [[ViewController2 alloc] init];


    NSUInteger index = 0;
    NSMutableArray *viewController = [NSMutableArray arrayWithObjects:[self showVCWithIndex:index], nil];

    [self.pageViewController setViewControllers:viewController
                                      direction:UIPageViewControllerNavigationDirectionForward
                                       animated:NO
                                     completion:nil];

    [self addChildViewController:self.pageViewController];
    [self.view addSubview:self.pageViewController.view];

    CGRect pageViewRect = self.view.bounds;
    self.pageViewController.view.frame = pageViewRect;

    [self.pageViewController didMoveToParentViewController:self];

}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController
      viewControllerBeforeViewController:(UIViewController *)viewController
{
    NSUInteger index = [self.vcArray indexOfObject:viewController];
    if ((index == 0) || (index == NSNotFound)) {
        return nil;
    }

    index--;
    return [self showVCWithIndex:index];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController
       viewControllerAfterViewController:(UIViewController *)viewController
{
    NSUInteger index = [self.vcArray indexOfObject:viewController];

    if (index == 2 || index == NSNotFound) {
        return nil;
    }

    index++;
    return [self showVCWithIndex:index];
}

- (UIViewController *)showVCWithIndex: (NSUInteger)index
{
    self.vcArray = [NSArray arrayWithObjects: _vController0, _vController1, _vController2, nil];

    UIViewController *currentVC = [self.vcArray objectAtIndex:index];

    return currentVC;
}

@end

修改得到了解决方案（这段代码有效，但我不确定我是否100％正确）

Answer 1

在UIPageViewController中设置视图控制器时，它必须是只有一个视图控制器的数组。方法-setViewControllers:direction:animated:completion:是如此误导。当我第一次创建页面视图控制器时，我遇到了同样的问题。

要允许您的网页浏览控制器显示其他视图控制器，请使用UIPageViewControllerDataSource方法-pageViewController:viewControllerBeforeViewController:和-pageViewController:viewControllerAfterViewController:返回它们。

Answer 2

当你打电话......

[self.pageViewController setViewControllers:[vcArray objectAtIndex:0] 
                                  direction:UIPageViewControllerNavigationDirectionForward 
                                   animated:NO
                                 completion:nil];

...您正在为分页视图控制器设置nil视图控制器。

[vcArray objectAtIndex:0]指向_vController0，在那一刻，nil（您还没有实例化它）。

在将控制器设置为分页之前，您必须使用[self.storyboard instatiateViewControllerWithIdentifier:@"YourViewControllerIdentifier"]从故事板中获取它，或者只是在使用Xib时调用alloc init。

将多个自定义UIViewControllers添加到UIPageViewController

2 个答案: