一、引言
UIPageViewController是iOS中少见的动画视图控制器之一，通过它既可以创建类似UIScrollView与UIPageControl结合的滚屏视图，也可以创建类似图书效果的炫酷翻页视图。UIPageViewController类似一个视图容器，其中每个具体的视图由各自的ViewController进行维护管理，UIPageViewController只进行协调与动画布置。下图可以很好的展现出UIPageViewControlelr的使用结构：
上图中，UIPageViewControllerDataSource协议为UIPageViewController提供数据支持，DataSource协议提供的数据来自各个ViewContoller自行维护，UIPageViewControllerDelegate中的回调可以对翻页动作，屏幕旋转动作等进行监听。UIPageViewController把从DataSource中获取到的视图数据渲染给View用于当前视图控制器的展示。
二、创建一个UIPageViewController
首先新建一个类作为翻页视图控制器中具体每一页视图的控制器，使其继承于UIViewController：
ModelViewController.h
#import <UIKit/UIKit.h>
@interface ModelViewController : UIViewController
+(ModelViewController *)creatWithIndex:(int)index;
@property(nonatomic,strong)UILabel * indexLabel;
@end
ModelViewController.m
#import "ModelViewController.h"
@interface ModelViewController ()
@end
@implementation ModelViewController
+(ModelViewController *)creatWithIndex:(int)index{
ModelViewController * con = [[ModelViewController alloc]init];
con.indexLabel = [[UILabel alloc]initWithFrame:CGRectMake(110, 200, 100, 30)];
con.indexLabel.text = [NSString stringWithFormat:@"第%d页",index];
[con.view addSubview:con.indexLabel];
return con;
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.view.backgroundColor = [UIColor redColor];
}
@end
在工程模板自带的ViewController.m文件中实现如下代码：
#import "ViewController.h"
#import "ModelViewController.h"
//遵守协议
@interface ViewController ()<UIPageViewControllerDataSource,UIPageViewControllerDelegate>
{
//翻页视图控制器对象
UIPageViewController * _pageViewControl;
//数据源数组
NSMutableArray * _dataArray;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//进行初始化
_pageViewControl = [[UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:@{UIPageViewControllerOptionSpineLocationKey:@0,UIPageViewControllerOptionInterPageSpacingKey:@10}];
self.view.backgroundColor = [UIColor greenColor];
//设置翻页视图的尺寸
_pageViewControl.view.bounds=self.view.bounds;
//设置数据源与代理
_pageViewControl.dataSource=self;
_pageViewControl.delegate=self;
//创建初始界面
ModelViewController * model = [ModelViewController creatWithIndex:1];
//设置初始界面
[_pageViewControl setViewControllers:@[model] direction:UIPageViewControllerNavigationDirectionReverse animated:YES completion:nil];
//设置是否双面展示
_pageViewControl.doubleSided = NO;
_dataArray = [[NSMutableArray alloc]init];
[_dataArray addObject:model];
[self.view addSubview:_pageViewControl.view];
}
//翻页控制器进行向前翻页动作 这个数据源方法返回的视图控制器为要显示视图的视图控制器
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController{
int index = (int)[_dataArray indexOfObject:viewController];
if (index==0) {
return nil;
}else{
return _dataArray[index-1];
}
}
//翻页控制器进行向后翻页动作 这个数据源方法返回的视图控制器为要显示视图的视图控制器
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController{
int index = (int)[_dataArray indexOfObject:viewController];
if (index==9) {
return nil;
}else{
if (_dataArray.count-1>=(index+1)) {
return _dataArray[index+1];
}else{
ModelViewController * model = [ModelViewController creatWithIndex:index+2];
[_dataArray addObject:model];
return model;
}
}
}
//屏幕旋转触发的代理方法
- (UIPageViewControllerSpineLocation) pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation{
return UIPageViewControllerSpineLocationMin;
}
//设置分页控制器的分页数
- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController {
return 10;
}
//设置初始的分页点
- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController{
return 0;
}
@end
上面创建了最简单的翻页视图控制器示例，效果如下图：
