iOS使用pageViewController实现多视图滑动切换

#import "ViewController.h"/// 当前controller
#import "MyViewController.h" /// 复用的controller 适用于每个控制器布局相同的情况下，，布局不同就创建不同的controller添加进来
#import " CollectionViewCell.h"/// 标题栏使用的collectionviewcell

@interface ViewController ()<UIPageViewControllerDelegate,UIPageViewControllerDataSource,UICollectionViewDelegate,UICollectionViewDataSource>{

 //// 记录当前页 当前标题位置

 NSInteger ld_currentIndex;

}

@property (nonatomic, strong) UIPageViewController *pageViewController;
@property (nonatomic, strong) NSMutableArray *controllersArr;/// 控制器数组
@property (nonatomic, strong) NSMutableArray * Array; /// 标题数组
@property (nonatomic, strong) UICollectionView * CollectionView; /// 标题collectionview

@end

@implementation ViewController


- (void)viewDidLoad {
 [super viewDidLoad];
 self.view.backgroundColor = [UIColor whiteColor];
 self.navigationController.navigationBar.translucent = NO;
 self.controllersArr = [NSMutableArray array];
 self. Array = [NSMutableArray array];
 //// 如果controller布局相同则循环创建MyViewController 添加进数组，，如果controller 布局不同 那就创建多个不同controller依次添加数组
 for (int i = 0; i < 10; i++) {
  MyViewController *con = [[MyViewController alloc]init];
  [self.controllersArr add :con];
  NSString *str = [NSString stringWithFormat:@"第 %d 页", i+1];
  con. string = str;
  [self. Array add :str];

 }
 [self createCollectionView];
 [self createPageViewController];
 [self setTheFirstPage];

}



/// 创建标题collectionview
- (void)createCollectionView{
 UICollectionViewFlowLayout *lay = [[UICollectionViewFlowLayout alloc] init];
 lay.itemSize = CGSizeMake(60, 30);
 lay.minimumLineSpacing = 0;
 lay.minimumInteritemSpacing = 0;
 lay.scrollDirection = UICollectionViewScrollDirectionHorizontal;
 self. CollectionView = [[UICollectionView alloc] initWith :CGRectMake(0, 34, 375, 30) collectionViewLayout:lay];
 self. CollectionView.showsHorizontalScrollIndicator = NO;
 self. CollectionView.backgroundColor = [UIColor whiteColor];
 self. CollectionView.delegate = self;
 self. CollectionView.dataSource = self;
 [self. CollectionView registerClass:[ CollectionViewCell class] forCellWithReuseIdentifier:@" Reuse"];
 [self.navigationController.view addSubview:self. CollectionView];


}

//// 标题collectionview的协议方法

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
 return self. Array.count;

}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
  CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@" Reuse" forIndexPath:indexPath];
 cell. Label.text = self. Array[indexPath.row];
 if (indexPath.row == ld_currentIndex) {
  cell. Label.textColor = [UIColor orangeColor];

 }else{

  cell. Label.textColor = [UIColor blackColor];

 }

 return cell;

}

//// 点击标题左右切换视图控制器------------再也不用看到好几个中间页面从屏幕快速闪过了------
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
 UIViewController *vc = [self.controllersArr  AtIndex:indexPath.row];
 if (indexPath.row > ld_currentIndex) {
  [self.pageViewController setViewControllers:@[vc] direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:^(BOOL finished) {

  }];

 } else {

  [self.pageViewController setViewControllers:@[vc] direction:UIPageViewControllerNavigationDirectionReverse animated:YES completion:^(BOOL finished) {

  }];

 }
 ld_currentIndex = indexPath.row;
 NSIndexPath *path = [NSIndexPath indexPathForRow:ld_currentIndex inSection:0];
 [self. CollectionView scrollToItemAtIndexPath:path atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
 [self. CollectionView reloadData];

}



/// 创建pageViewController
- (void)createPageViewController {
 NSDictionary *option = [NSDictionary dictionaryWith :[NSNumber numberWithInteger:0] forKey:UIPageViewControllerOptionInterPageSpacingKey];
 _pageViewController = [[UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:option];
 _pageViewController.delegate = self;
 _pageViewController.dataSource = self;
 [self addChildViewController:_pageViewController];
 [self.view addSubview:_pageViewController.view];

}

/// 展示上一页
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController {
 NSInteger index = [self.controllersArr indexOf :viewController];
 if (index == 0 || (index == NSNotFound)) {
  return nil;

 }

 index--;
 return [self.controllersArr  AtIndex:index];

}

/// 展示下一页
- (nullable UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController {
 NSInteger index = [self.controllersArr indexOf :viewController];
 if (index == self.controllersArr.count - 1 || (index == NSNotFound)) {
  return nil;

 }

 index++;
 return [self.controllersArr  AtIndex:index];

}

/// 将要滑动切换的时候
- (void)pageViewController:(UIPageViewController *)pageViewController willTransitionToViewControllers:(NSArray<UIViewController *> *)pendingViewControllers {
 UIViewController *nextVC = [pendingViewControllers first ];
 NSInteger index = [self.controllersArr indexOf :nextVC];
 ld_currentIndex = index;

}

/// 滑动结束后
- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray<UIViewController *> *)previousViewControllers transitionCompleted:(BOOL)completed {
 if (completed) {
  NSIndexPath *path = [NSIndexPath indexPathForRow:ld_currentIndex inSection:0];
  [self. CollectionView scrollToItemAtIndexPath:path atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
  [self. CollectionView reloadData];

  NSLog(@">>>>>>>>> %ld", (long)ld_currentIndex);

 } 

}

/// 设置默认显示的是哪个页面（controller）
- (void)setTheFirstPage{
 UIViewController *vc = [self.controllersArr  AtIndex:ld_currentIndex];
 [self.pageViewController setViewControllers:@[vc] direction:UIPageViewControllerNavigationDirectionReverse animated:YES completion:nil];

}

- (void)didReceiveMemoryWarning {
 [super didReceiveMemoryWarning];
 // Dispose of any resources that can be recreated.

}

 CollectionViewCell
@implementation  CollectionViewCell


- (instancetype)initWith :(CGRect) {
 self = [super initWith : ];
 if (self) {
  [self createView];

 }
 return self;

}

- (void)createView{
 self. Label = [[UILabel alloc] initWith :CGRectMake(0, 0, self.contentView. .size.width, self.contentView. .size.height)];
 [self.contentView addSubview:self. Label];
 self. Label.font = [UIFont systemFontOfSize:14];

}
@end