UITableView 刷新头部时,头部每次都变为开始的状态,无法记录当前的状态

本文详细介绍了在UITableView中实现点击按钮后刷新表格视图,同时保持头部区域视图及其按钮状态不变的技术细节。通过定义全局字典存储按钮实例,确保每次刷新时使用同一实例,避免了重复初始化导致的问题。

比如UITableView中头部视图为这里写图片描述

点击按钮后,头部进行刷新,头部区域视图改变,并且下面出现cell,如图:
这里写图片描述
此功能的实现应该用,头部的刷新功能,利用代码:

//刷新表格视图的分区的头视图
[_historyTableView reloadSections:[NSIndexSet indexSetWithIndex:index] withRowAnimation:UITableViewRowAnimationFade];

但是实现过程中会出现一个问题,就是刷新后头部视图部分,开关按钮仍然为灰白按钮,那是因为每次刷新时,都会去重新初始化头部,此开关按钮也就会被重新初始化。由于此开关按钮是自己封装的,所以可以在封装里面的初始化中加一个判断:
需要定义一个bool值,
首先在控制器里面,每次打开开关按钮时将bool置为yes,刷新时,会去封装的代码中进行初始化,所以初始化代码中应:

- (instancetype)initWithframe:(CGRect )frame{
    self = [super init];
    if (self) {
        [self setBackgroundImage:[UIImage imageNamed:@"gray"] forState:UIControlStateNormal];
        [self addTarget:self action:@selector(changeImageAndSlide:) forControlEvents:UIControlEventTouchUpInside];

        self.frame = frame;
        self.tempFrame = frame;
        _sliderButton = [[UIButton alloc]initWithFrame:CGRectMake(2, 2, 27, 27)];


        if (_isClicked== YES) {
            /**
             *   点击过后;
             */
            [_sliderButton setBackgroundImage:[UIImage imageNamed:@"orange"] forState:UIControlStateNormal];
            _sliderButton.frame = CGRectMake(41,  2, 27, 27);
        } else {
            [_sliderButton setBackgroundImage:[UIImage imageNamed:@"white"] forState:UIControlStateNormal];
            _sliderButton.frame = CGRectMake(2, 2, 27, 27);

        }

        [_sliderButton addTarget:self action:@selector(slide:) forControlEvents:UIControlEventTouchUpInside];

        [self addSubview:_sliderButton];

    }
    return self;

}

这样操作后会发现还是无法实现,那是因为刚才点击的那个头部的开关按钮,点击完后开始刷新,刷新时重新初始化时,又初始化了一个开关按钮,不是刚才点击的那个头部开关按钮了。为了保证刚才点击的头部和等下刷新时的头部是同一个,可以在控制器中初始化头部的代码中这样来实现:
首先声明一个存放的字典:

@property (nonatomic, strong) NSMutableDictionary *BigButtonDic; // 存放表头名称的数组
//为每个分区添加头视图
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{

//开关按钮的创建(每次将创建的开关按钮,存到字典中,再次初始化时,如果已经有了,就不好初始化新的了,而是拿出之前的来使用)
 ButtonBig *switchBtn = [self.BigButtonDic objectForKey:[NSString stringWithFormat:@"%lu", (long)section]];
    if (switchBtn == nil) {
        switchBtn = [[ButtonBig alloc]initWithframe:CGRectMake(0, 0, 70, 31)];
        [self.BigButtonDic setObject:switchBtn forKey:[NSString stringWithFormat:@"%lu", (long)section]];
    }
}

如此就可以实现了。

class GeneralListViewPresenter<Delegate: GeneralListViewPresentable, HeaderPresenter: GeneralListViewCellOverallDataSettable, ItemPresenter: GeneralListViewCellOverallDataSettable, FooterPresenter: GeneralListViewCellOverallDataSettable>: NSObject, UITableViewDataSource, UITableViewDelegate, UICollectionViewDataSource where Delegate.Item == ItemPresenter.T, Delegate.Header == HeaderPresenter.T, Delegate.Footer == FooterPresenter.T { typealias Item = Delegate.Item typealias Header = Delegate.Header typealias Footer = Delegate.Footer typealias SectionData = GeneralListViewSectionData<Header, Item, Footer> weak var delegate: Delegate? var sections: [SectionData] { return delegate?.sectionDataList() ?? [] } private var _savedSections: [SectionData] = [] //MARK: UITableViewDataSource func numberOfSections(in tableView: UITableView) -> Int { //保障深拷贝? _savedSections = sections return _savedSections.count } func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return _savedSections[section].items.count } func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { guard let delegate = self.delegate else { fatalError() } let item = _savedSections[indexPath.section].items[indexPath.row] let identifier = delegate.identifierForItem(item) let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath) if let presenter = cell as? ItemPresenter { presenter.apply(item, at: indexPath) } return cell } //MARK: UITableViewDelegate func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? { guard let delegate = self.delegate else { fatalError() } guard let item = _savedSections[section].header else { return nil } let identifier = delegate.identifierForHeader(item) let header = tableView.dequeueReusableHeaderFooterView(withIdentifier: identifier) if let presenter = header as? HeaderPresenter { presenter.apply(item, at: IndexPath(row: 0, section: section)) } return header } func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? { guard let delegate = self.delegate else { fatalError() } guard let item = _savedSections[section].footer else { return UIView() } let identifier = delegate.identifierForFooter(item) let footer = tableView.dequeueReusableHeaderFooterView(withIdentifier: identifier) if let presenter = footer as? FooterPresenter { presenter.apply(item, at: IndexPath(row: 0, section: section)) } return footer } func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat { return UITableView.automaticDimension } func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat { return UITableView.automaticDimension } func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat { return UITableView.automaticDimension } //MARK: UICollectionViewDataSource func numberOfSections(in collectionView: UICollectionView) -> Int { _savedSections = sections return _savedSections.count } func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { return _savedSections[section].items.count } func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { guard let delegate = self.delegate else { fatalError() } let item = _savedSections[indexPath.section].items[indexPath.row] let identifier = delegate.identifierForItem(item) let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath) //设备列表大图模式NVR通道收藏/取消收藏 if let newCell = cell as? OnlineChannelCardCell { newCell.collecAction = { (collect, device, channel) in if let ctr = UIViewController.current as? OnlineDeviceListViewController { ctr.collectButtonClicked(isCollect: collect, device: device, channel: channel) } } //设备列表大图模式NVR Channel进入Help页面 newCell.helpAction = { (device, channel) in let storyboard = UIStoryboard(name: "DeviceList", bundle: nil) if let ctr = storyboard.instantiateViewController(withIdentifier: "DeviceOfflineHelpViewController") as? DeviceOfflineHelpViewController, let rootCtr = UIViewController.current as? OnlineDeviceListViewController { ctr.deviceListType = device.listType; ctr.deviceType = device.deviceType ctr.device = device ctr.channelID = TPSSChannelId(channel.channelId) rootCtr.navigationController?.pushViewController(ctr, animated: true); } } } if let presenter = cell as? ItemPresenter { presenter.apply(item, at: indexPath) } return cell } func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView { if kind == UICollectionView.elementKindSectionHeader { guard let delegate = self.delegate else { fatalError() } guard let item = _savedSections[indexPath.section].header else { fatalError() } let identifier = delegate.identifierForHeader(item) let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: identifier, for: indexPath) if let presenter = header as? HeaderPresenter { presenter.apply(item, at: indexPath) } return header } else if kind == UICollectionView.elementKindSectionFooter { guard let delegate = self.delegate else { fatalError() } guard let item = _savedSections[indexPath.section].footer else { fatalError() } let identifier = delegate.identifierForFooter(item) let footer = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: identifier, for: indexPath) if let presenter = footer as? FooterPresenter { presenter.apply(item, at: indexPath) } return footer } fatalError() } }
最新发布
10-22
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