CollectionView section - QDDCoder/LZLearniOS GitHub Wiki

private lazy var layout = UICollectionViewFlowLayout()
private lazy var collectionView = UICollectionView(frame: CGRect(x: 10*PionWidth, y: NAVBAR_HEIGHT, width: ScreenW-20*PionWidth, height: ScreenH-NAVBAR_HEIGHT),collectionViewLayout: layout).then {
    $0.backgroundColor = .white
    $0.register(LZRXCollectionCell.self, forCellWithReuseIdentifier: "LZRXCollectionCell")
    $0.register(RXSwiftCollectionHeadView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "headerViewId")
    //高度代理
    $0.delegate=self
    
    //拖动使用
    $0.dropDelegate=self
    $0.dragDelegate=self
    //开启可拖动
    $0.dragInteractionEnabled = true
    //弹簧加载是一种导航和激活控件的方式，在整个系统中，当处于 dragSession 的时候，只要悬浮在cell上面，就会高亮，然后就会激活
    $0.isSpringLoaded=true
    //重排序节奏）可以调节集合视图重排序的响应性。 是 CollectionView 独有的属性（相对于UITableView），因为 其独有的二维网格的布局，因此在重新排序的过程中有时候会发生元素回流了，有时候只是移动到别的位置，不想要这样的效果，就可以修改这个属性改变其相应性
    $0.reorderingCadence = .slow
    
    
    //隐藏纵向滑动线
    $0.showsVerticalScrollIndicator = false
    
    //系统自动调整scrollView.contentInset保证滚动视图不被tabbar,navigationbar遮挡
    $0.contentInsetAdjustmentBehavior = .scrollableAxes
    
    // 点击事件
    $0.rx.itemSelected.map {[weak self] (indexPath) in
        return (indexPath,self!.dataSource[indexPath])
    }.subscribe(onNext:{(index,model) in
        ToastView.instance.showToast(content: "点击了===>>>\(index.section)===>>>\(model.name)")
    }).disposed(by: disposeBag)
    

    self.view.addSubview($0)
}
    

//设置数据绑定的中间件
private var dataSource = RxCollectionViewSectionedReloadDataSource<SectionModel<String,HomeCategoryModel>> { (_, collectionView, indexPath, item) -> UICollectionViewCell in
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "LZRXCollectionCell", for: indexPath) as! LZRXCollectionCell
    cell.textInfo.text=item.name
    cell.backgroundColor = .randomColor
    cell.dragStateDidChange(.lifting)
    return cell
}.then {
    // 设置sectionHeader
    $0.configureSupplementaryView={(model, collection, info, indexPath) -> UICollectionReusableView in
        let header = collection.dequeueReusableSupplementaryView(ofKind: info, withReuseIdentifier: "headerViewId", for: indexPath) as! RXSwiftCollectionHeadView
        header.titleLabel.text=model.sectionModels[indexPath.section].model
        header.backgroundColor = .randomColor
        return header
    }
    
    //设置可移动
    $0.canMoveItemAtIndexPath={(dataSourceIn,indexPath) -> Bool in
        return true
    }
}

private var response:BehaviorSubject<[SectionModel<String, HomeCategoryModel>]>?
private var dataModel=[SectionModel(model: "我的频道", items:
    [
        HomeCategoryModel(withName: "关注", withJump: UIViewController.self),
        HomeCategoryModel(withName: "推荐", withJump: UIViewController.self),
        HomeCategoryModel(withName: "视频", withJump: UIViewController.self),
        HomeCategoryModel(withName: "热点", withJump: UIViewController.self),
        HomeCategoryModel(withName: "北京", withJump: UIViewController.self),
        HomeCategoryModel(withName: "新时代", withJump: UIViewController.self),
        HomeCategoryModel(withName: "图片", withJump: UIViewController.self),
        HomeCategoryModel(withName: "头条号", withJump: UIViewController.self),
        HomeCategoryModel(withName: "娱乐", withJump: UIViewController.self),
        HomeCategoryModel(withName: "问答", withJump: UIViewController.self),
        HomeCategoryModel(withName: "体育", withJump: UIViewController.self),
        HomeCategoryModel(withName: "科技", withJump: UIViewController.self),
        HomeCategoryModel(withName: "懂车帝", withJump: UIViewController.self),
        HomeCategoryModel(withName: "财经", withJump: UIViewController.self),
        HomeCategoryModel(withName: "军事", withJump: UIViewController.self),
        HomeCategoryModel(withName: "国际", withJump: UIViewController.self),
    ]),
    SectionModel(model: "频道推荐", items:
    [
        HomeCategoryModel(withName: "健康", withJump: UIViewController.self),
        HomeCategoryModel(withName: "冬奥", withJump: UIViewController.self),
        HomeCategoryModel(withName: "特产", withJump: UIViewController.self),
        HomeCategoryModel(withName: "房产", withJump: UIViewController.self),
        HomeCategoryModel(withName: "小说", withJump: UIViewController.self),
        HomeCategoryModel(withName: "时尚", withJump: UIViewController.self),
        HomeCategoryModel(withName: "历史", withJump: UIViewController.self),
        HomeCategoryModel(withName: "育儿", withJump: UIViewController.self),
        HomeCategoryModel(withName: "直播", withJump: UIViewController.self),
        HomeCategoryModel(withName: "搞笑", withJump: UIViewController.self),
        HomeCategoryModel(withName: "数码", withJump: UIViewController.self),
        HomeCategoryModel(withName: "美食", withJump: UIViewController.self),
        HomeCategoryModel(withName: "养生", withJump: UIViewController.self),
        HomeCategoryModel(withName: "电影", withJump: UIViewController.self),
        HomeCategoryModel(withName: "手机", withJump: UIViewController.self),
        HomeCategoryModel(withName: "旅游", withJump: UIViewController.self),
        HomeCategoryModel(withName: "宠物", withJump: UIViewController.self),
        HomeCategoryModel(withName: "情感", withJump: UIViewController.self),
    ]
)]

extension LZRXCollectionViewSectionVC: UICollectionViewDelegate,UICollectionViewDelegateFlowLayout {
    
    // 设置Cell的大小
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = dataModel[indexPath.section].items[indexPath.row].name.ga_widthForComment(fontSize: 14, height: 20*PionHeight)
        return CGSize(width: width+20*PionWidth, height: 30*PionHeight)
    }
    
    //竖向滚动表示:行cell之间的间隔
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 10*PionWidth
    }
    
    //竖向滚动表示:行cell之间的列间距 注意:和Cell设置大小时的冲突,一般使用设置Cell 大小就行了。特殊应用场景,在cell自适应大小的时候使用
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        return 10*PionWidth
    }
    
    //foot的大小
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
        return CGSize(width:0 , height: 0*PionHeight)
    }
    
    //header的大小
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
        return CGSize(width: ScreenW-20*PionWidth, height: 40*PionHeight)
    }
}

extension LZRXCollectionViewSectionVC:UICollectionViewDragDelegate{
    //可拖动的item集合
    func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
        guard indexPath.section != 1 else {
            return []
        }
        let item = self.dataModel[indexPath.section].items[indexPath.row].name
        let itemProvider = NSItemProvider(object: item as NSString)
        let dragItem = UIDragItem(itemProvider: itemProvider)
        dragItem.localObject = item
        //开始拖动 的indexPath
        dragingIndexPath = indexPath
        return [dragItem]
    }
}

extension LZRXCollectionViewSectionVC:UICollectionViewDropDelegate
{
    //拖动的数据交换 通过coordinator我们可以获取到操作类型，是move还是copy。
    func collectionView(_ collectionView: UICollectionView, performDropWith coordinator: UICollectionViewDropCoordinator) {
        // 交换目标indexPath
        guard let destinationIndexPath = coordinator.destinationIndexPath else {
            return
        }
        switch coordinator.proposal.operation {
        case .move:
            let items = coordinator.items
            // 交换的发起item和indexPath
            if let item = items.first, let sourceIndexPath = item.sourceIndexPath {
                //执行批量更新
                collectionView.performBatchUpdates({
                    //move 操作后，需要把之前的位置删除掉，在新的位置进行插入
                    let tempItemp = self.dataModel[destinationIndexPath.section].items[sourceIndexPath.row]
                    self.dataModel[destinationIndexPath.section].items.remove(at: sourceIndexPath.row)
                    self.dataModel[destinationIndexPath.section].items.insert(tempItemp, at: destinationIndexPath.row)
                    collectionView.deleteItems(at: [sourceIndexPath])
                    collectionView.insertItems(at: [destinationIndexPath])
                    response?.onNext(dataModel)
                })
                //将项目动画化到视图层次结构中的任意位置
                coordinator.drop(item.dragItem, toItemAt: destinationIndexPath)
            }
            break
        default:
            return
        }
    }
    
    //设置拖动样式
    func collectionView(_ collectionView: UICollectionView, dropSessionDidUpdate session: UIDropSession, withDestinationIndexPath destinationIndexPath: IndexPath?) -> UICollectionViewDropProposal {
        //由于“我的频道”和“频道推荐”是禁止互相滑动的，所以，拖拽的起始dragingIndexPath和目标destinationIndexPath的section不一样，就表示跨区了，设置其为forbidden。
        if dragingIndexPath?.section != destinationIndexPath?.section {
            return UICollectionViewDropProposal(operation: .forbidden)
        }else{
            if session.localDragSession != nil {
                if collectionView.hasActiveDrag {
                    return UICollectionViewDropProposal(operation: .move, intent: .insertAtDestinationIndexPath)
                } else {
                    return UICollectionViewDropProposal(operation: .copy, intent: .insertAtDestinationIndexPath)
                }
            } else {
                return UICollectionViewDropProposal(operation: .forbidden)
            }
        }
    }
}