宁波哪里可以做网站,企业网站源码哪个好,网站管理系统安装,3a公司网络营销方案效果图 实现逻辑和原理
就是在 didEndDisplayingCell 方法中通过indexPathsForVisibleItems 接口获取当前可见的cell对应的indexPath#xff0c; 然后获取到item最小的那一个#xff0c;即可#xff0c;同时#xff0c;还要在 willDisplayCell 方法中直接设置标题的选中属…效果图 实现逻辑和原理
就是在 didEndDisplayingCell 方法中通过indexPathsForVisibleItems 接口获取当前可见的cell对应的indexPath 然后获取到item最小的那一个即可同时还要在 willDisplayCell 方法中直接设置标题的选中属性否则 由于重用机制导致选中的展示错乱
代码
//
// LBLinkedContentView.m
// LBTwoLinkedScrollingCollectionView
//
// Created by mac on 2024/6/25.
//#import LBLinkedContentView.h
#import LBLinkedContentViewTittleCell.h
#import LBLinkedContentViewContentCell.hinterface LBLinkedContentView () UICollectionViewDelegate, UICollectionViewDataSourceproperty (nonatomic, strong) UICollectionView *titleView;
property (nonatomic, strong) UICollectionView *contentView;property (nonatomic, strong) NSMutableArray *titleArray;
property (nonatomic, strong) NSMutableArray *contentArray;property (nonatomic, strong) NSIndexPath *selectedGroupIndex;endimplementation LBLinkedContentView- (instancetype)initWithFrame:(CGRect)frame
{if (self [super initWithFrame:frame]) {[self configData];[self setUpUI];}return self;
}- (void)setUpUI
{[self addSubview:self.titleView];[self addSubview:self.contentView];[self.titleView reloadData];[self.contentView reloadData];self.selectedGroupIndex [NSIndexPath indexPathForRow:0 inSection:0];LBLinkedContentViewTittleCell *titleCell [self.titleView cellForItemAtIndexPath:self.selectedGroupIndex];titleCell.selected YES;
}#pragma mark - configData- (void)configData
{for (int i 0; i 10; i ) {NSString *title [NSString stringWithFormat:%d,i];[self.titleArray addObject:title];NSMutableArray *array [NSMutableArray array];for (int j 0; j 10; j ) {NSString *content [NSString stringWithFormat:第%d分区第%d条, i,j];[array addObject:content];}[self.contentArray addObject:array];}
}#pragma mark - data Delegate- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{if (collectionView self.contentView) {LBLinkedContentViewContentCell *cell [collectionView dequeueReusableCellWithReuseIdentifier:NSStringFromClass([LBLinkedContentViewContentCell class]) forIndexPath:indexPath];NSString *title self.contentArray[indexPath.section][indexPath.item];[cell updateWithContent:title];return cell;}LBLinkedContentViewTittleCell *cell [collectionView dequeueReusableCellWithReuseIdentifier:NSStringFromClass([LBLinkedContentViewTittleCell class]) forIndexPath:indexPath];[cell updateWithIndexPath:indexPath];return cell;
}- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{if (collectionView self.titleView) {return 1;}return self.contentArray.count;
}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{return 10;
}- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath
{if (collectionView self.titleView) {if (self.selectedGroupIndex [self.selectedGroupIndex compare:indexPath] NSOrderedSame) {cell.selected YES;} else {cell.selected NO;}}
}- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath
{if (collectionView self.contentView) {[self handleGroupViewWithIndex:nil];}
}#pragma mark - private- (void)handleGroupViewWithIndex:(NSIndexPath *)indexPathCell
{NSArray NSIndexPath * *visibleIndexPaths [self.contentView indexPathsForVisibleItems];if (!visibleIndexPaths.count) {return;}NSInteger section indexPathCell ? indexPathCell.section : [self.contentView numberOfSections] - 1;for (NSIndexPath *indexPath in visibleIndexPaths) {if (indexPath.section section) {section indexPath.section;}}NSIndexPath *groupIndexPath [NSIndexPath indexPathForItem:section inSection:0];if(self.selectedGroupIndex [self.selectedGroupIndex compare:groupIndexPath] ! NSOrderedSame) {LBLinkedContentViewTittleCell *cell [self.titleView cellForItemAtIndexPath:self.selectedGroupIndex];cell.selected NO;self.selectedGroupIndex groupIndexPath;LBLinkedContentViewTittleCell *titleCell [self.titleView cellForItemAtIndexPath:groupIndexPath];titleCell.selected YES;[self.titleView scrollToItemAtIndexPath:groupIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:YES];}
}#pragma mark - lazy load- (UICollectionView *)titleView
{if (!_titleView) {UICollectionViewFlowLayout *layout [[UICollectionViewFlowLayout alloc] init];layout.minimumLineSpacing 29;layout.minimumInteritemSpacing 29;layout.scrollDirection UICollectionViewScrollDirectionHorizontal;layout.itemSize CGSizeMake(40, 50);_titleView [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(self.bounds), 60) collectionViewLayout:layout];[_titleView registerClass:[LBLinkedContentViewTittleCell class] forCellWithReuseIdentifier:NSStringFromClass([LBLinkedContentViewTittleCell class])];_titleView.delegate self;_titleView.dataSource self;}return _titleView;
}- (UICollectionView *)contentView
{if (!_contentView) {UICollectionViewFlowLayout *layout [[UICollectionViewFlowLayout alloc] init];layout.minimumLineSpacing 10;layout.minimumInteritemSpacing 10;layout.itemSize CGSizeMake(100, 80);layout.scrollDirection UICollectionViewScrollDirectionHorizontal;layout.sectionInset UIEdgeInsetsMake(0, 40, 0, 40);_contentView [[UICollectionView alloc] initWithFrame:CGRectMake(0, 80, CGRectGetWidth(self.bounds), 80) collectionViewLayout:layout];[_contentView registerClass:[LBLinkedContentViewContentCell class] forCellWithReuseIdentifier:NSStringFromClass([LBLinkedContentViewContentCell class])];_contentView.delegate self;_contentView.dataSource self;_contentView.backgroundColor [UIColor yellowColor];}return _contentView;
}- (NSMutableArray *)titleArray
{if (!_titleArray) {_titleArray [NSMutableArray array];}return _titleArray;
}- (NSMutableArray *)contentArray
{if (!_contentArray) {_contentArray [NSMutableArray array];}return _contentArray;
}end
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