pageViewController实现多视图（控制器）滑动切换

先看一下效果动画





类似的界面做过不少，，在几个APP中都有用到过，，再次之前不了解uipageViewController 曾经的思路有两个现在想想都觉得繁琐，，

之前的思路1：使用嵌套，collectionview嵌套，每个item中添加内容

之前的思路2：使用scrollview 在上面创建一个一个的controller 实现左右滑动

这两个思路无疑是可以实现的 并且可以实现每个页面的重用，，滑动等都可以 唯独一点不好就是当停留在第一页的时候 点击标题栏第五页，，那么平移的过程就是第一页到第五页，，所有的页面从屏幕快速闪过，，并且看到现在很多APP都是这样的。。在此之前我是用的思路2，，为了避免跨页面切换出现的中间几个页面闪过的过程，，直接把平移动画关闭了。。直到使用了uipageViewController，，赶紧把项目中的给换掉了

代码不多150行以内

#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 "TitleCollectionViewCell.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 *titleArray; /// 标题数组

@property (nonatomic,
strong)
UICollectionView *titleCollectionView; /// 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.titleArray = [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
addObject:con];

        NSString *str = [NSString
stringWithFormat:@"第 %d
页", i+1];

        con.titlestring = str;

        [self.titleArray
addObject: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.titleCollectionView = [[UICollectionView
alloc] initWithFrame:CGRectMake(0,
34,
375, 30)
collectionViewLayout:lay];

    self.titleCollectionView.showsHorizontalScrollIndicator
= NO;

    self.titleCollectionView.backgroundColor
= [UIColor
whiteColor];

    self.titleCollectionView.delegate
= self;

    self.titleCollectionView.dataSource
= self;

    [self.titleCollectionView
registerClass:[TitleCollectionViewCell
class] forCellWithReuseIdentifier:@"titleReuse"];

    [self.navigationController.view
addSubview:self.titleCollectionView];

}

//// 标题collectionview的协议方法

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{

    return
self.titleArray.count;

}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath
*)indexPath {

    TitleCollectionViewCell *cell = [collectionView
dequeueReusableCellWithReuseIdentifier:@"titleReuse"
forIndexPath:indexPath];

    cell.titleLabel.text =
self.titleArray[indexPath.row];

    if (indexPath.row ==
ld_currentIndex) {

        cell.titleLabel.textColor = [UIColor
orangeColor];

    }else{

        cell.titleLabel.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
objectAtIndex: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.titleCollectionView
scrollToItemAtIndexPath:path
atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally
animated:YES];

    [self.titleCollectionView
reloadData];

}

/// 创建pageViewController

- (void)createPageViewController {

    NSDictionary *option = [NSDictionary
dictionaryWithObject:[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
indexOfObject:viewController];

    if (index ==
0 || (index == NSNotFound)) {

        return
nil;

    }

    index--;

    return [self.controllersArr
objectAtIndex:index];

}

/// 展示下一页

- (nullable
UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController
*)viewController {

    NSInteger index = [self.controllersArr
indexOfObject:viewController];

    if (index ==
self.controllersArr.count -
1 || (index == NSNotFound)) {

        return
nil;

    }

    index++;

    return [self.controllersArr
objectAtIndex:index];

}

/// 将要滑动切换的时候

- (void)pageViewController:(UIPageViewController *)pageViewController willTransitionToViewControllers:(NSArray<UIViewController
*> *)pendingViewControllers {

    UIViewController *nextVC = [pendingViewControllers
firstObject];

    NSInteger index = [self.controllersArr
indexOfObject: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.titleCollectionView
scrollToItemAtIndexPath:path
atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally
animated:YES];

        [self.titleCollectionView
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
objectAtIndex:ld_currentIndex];

    [self.pageViewController
setViewControllers:@[vc]
direction:UIPageViewControllerNavigationDirectionReverse
animated:YES
completion:nil];

}

- (void)didReceiveMemoryWarning {

    [super
didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

TitleCollectionViewCell

@implementation TitleCollectionViewCell

- (instancetype)initWithFrame:(CGRect)frame{

    self = [super
initWithFrame:frame];

    if (self) {

        [self
createView];

    }

    return
self;

}

- (void)createView{

    self.titleLabel = [[UILabel
alloc]
initWithFrame:CGRectMake(0,
0, self.contentView.frame.size.width,
self.contentView.frame.size.height)];

    [self.contentView
addSubview:self.titleLabel];

    self.titleLabel.font
= [UIFont
systemFontOfSize:14];

}

@end

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链接: https://pan.baidu.com/s/1i4BF1YX 密码: tfau