三、UIPageViewController中方法使用解析
//创建翻页视图控制器对象
- (instancetype)initWithTransitionStyle:(UIPageViewControllerTransitionStyle)style navigationOrientation:(UIPageViewControllerNavigationOrientation)navigationOrientation options:(nullable NSDictionary<NSString *, id> *)options;
上面方法用于创建视图控制器对象，其中UIPageViewControllerTransitionStyle参数设置翻页控制器的风格，枚举如下：
typedef NS_ENUM(NSInteger, UIPageViewControllerTransitionStyle) {
UIPageViewControllerTransitionStylePageCurl = 0, //类似于书本翻页效果
UIPageViewControllerTransitionStyleScroll = 1 // 类似于ScrollView的滑动效果
};
如果设置为UIPageViewControllerTransitionStyleCurl，翻页效果如下图所示：
上面初始化方法中的UIPageViewControllerNavigationOrientation属性设置翻页的方向，枚举如下：
typedef NS_ENUM(NSInteger, UIPageViewControllerNavigationOrientation) {
UIPageViewControllerNavigationOrientationHorizontal = 0,//水平翻页
UIPageViewControllerNavigationOrientationVertical = 1//竖直翻页
};
options参数用于设置翻页视图控制器的配置字典，其可以设置的配置键值如下：
//这个键需要设置为UIPageViewControllerOptionSpineLocationKey枚举值对应的NSNumber对象 设置翻页控制器的书轴 后面会介绍
NSString * const UIPageViewControllerOptionSpineLocationKey;
//这个键需要设置为NSNumber类型 设置每页视图的间距 用于滚动视图风格的
NSString * const UIPageViewControllerOptionInterPageSpacingKey;
下面是UIPageViewController的一些常用属性与方法：
//设置数据源
@property (nullable, nonatomic, weak) id <UIPageViewControllerDelegate> delegate;
//设置代理
@property (nullable, nonatomic, weak) id <UIPageViewControllerDataSource> dataSource;
//获取翻页风格
@property (nonatomic, readonly) UIPageViewControllerTransitionStyle transitionStyle;
//获取翻页方向
@property (nonatomic, readonly) UIPageViewControllerNavigationOrientation navigationOrientation;
//获取书轴类型
@property (nonatomic, readonly) UIPageViewControllerSpineLocation spineLocation;
//设置是否双面显示
@property (nonatomic, getter=isDoubleSided) BOOL doubleSided;
//设置要显示的视图控制器
- (void)setViewControllers:(nullable NSArray<UIViewController *> *)viewControllers direction:(UIPageViewControllerNavigationDirection)direction animated:(BOOL)animated completion:(void (^ __nullable)(BOOL finished))completion;
上面只有spineLocation属性有些难于理解，其枚举如下：
typedef NS_ENUM(NSInteger, UIPageViewControllerSpineLocation) {
//对于SCrollView类型的滑动效果 没有书轴 会返回下面这个枚举值
UIPageViewControllerSpineLocationNone = 0,
//以左边或者上边为轴进行翻转 界面同一时间只显示一个View
UIPageViewControllerSpineLocationMin = 1,
//以中间为轴进行翻转 界面同时可以显示两个View
UIPageViewControllerSpineLocationMid = 2,
//以下边或者右边为轴进行翻转 界面同一时间只显示一个View
UIPageViewControllerSpineLocationMax = 3
};
将上面的示例代码修改几个地方如下：
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_pageViewControl = [[UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationVertical options:@{UIPageViewControllerOptionSpineLocationKey:@2,UIPageViewControllerOptionInterPageSpacingKey:@10}];
self.view.backgroundColor = [UIColor greenColor];
_pageViewControl.view.bounds=self.view.bounds;
_pageViewControl.dataSource=self;
_pageViewControl.delegate=self;
ModelViewController * model = [ModelViewController creatWithIndex:1];
ModelViewController * model2 = [ModelViewController creatWithIndex:2];
[_pageViewControl setViewControllers:@[model,model2] direction:UIPageViewControllerNavigationDirectionReverse animated:YES completion:nil];
_pageViewControl.doubleSided = YES;
_dataArray = [[NSMutableArray alloc]init];
[_dataArray addObject:model];
[self.view addSubview:_pageViewControl.view];
}
- (UIPageViewControllerSpineLocation) pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation{
return UIPageViewControllerSpineLocationMid;
}
运行效果如下图所示：
四、UIPageViewControllerDataSource中方法解析
//向前翻页展示的ViewController
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController;
//向后翻页展示的ViewController
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController;
//设置分页控制器的分页点数
- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController NS_AVAILABLE_IOS(6_0);
//设置当前分页控制器所高亮的点
- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController NS_AVAILABLE_IOS(6_0);
五、UIPageViewControllerDelegate中方法解析
//翻页视图控制器将要翻页时执行的方法
- (void)pageViewController:(UIPageViewController *)pageViewController willTransitionToViewControllers:(NSArray<UIViewController *> *)pendingViewControllers NS_AVAILABLE_IOS(6_0);
//翻页动画执行完成后回调的方法
- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray<UIViewController *> *)previousViewControllers transitionCompleted:(BOOL)completed;
//屏幕防线改变时回到的方法，可以通过返回值重设书轴类型枚举
- (UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation;
