UITabView/UICollectionView 全选问题

SkySeraph July. 30th 2016

Email：skyseraph00@163.com

更多精彩请直接访问SkySeraph个人站点：www.skyseraph.com

The Issue

Recently in my new project I need to select all the cell data in my UITabViewCell and UICollectionViewCell, and need to do some operations with all the cells(like delete etc.), What I do as follows:

UITabView

private func selectAll(select: Bool) {let numSections = mListTableView?.numberOfSectionsif let numSections = numSections {for numSection in  0 ..< numSections{let numItems = mListTableView?.numberOfRowsInSection(numSection)if let numItems = numItems {for numItem in 0 ..< numItems {selectCell(NSIndexPath(forRow: numItem, inSection: numSection), select: select)}}}}
}private func selectCell(indexPath : NSIndexPath, select: Bool) {if mListTableView?.cellForRowAtIndexPath(indexPath) != nil {let cell = mListTableView?.cellForRowAtIndexPath(indexPath) as! DownloadListViewCell//cell.setSelected(select, animated: true)cell.setSelectForDelete(select)  // select status UI in UITabViewCellmDownloadList[indexPath.row].selectToDelete = select  // Pojo data
    }
}

View Code

UICollectionView

private func selectAll(select: Bool) {let numSections = mMyOfflineCollectView?.numberOfSections()if let numSections = numSections {for numSection in  0 ..< numSections{let numItems = mMyOfflineCollectView?.numberOfItemsInSection(numSection)if let numItems = numItems {for numItem in 0 ..< numItems {selectCell(NSIndexPath(forRow: numItem, inSection: numSection), flag: select)}}}}
}private func selectCell(indexPath : NSIndexPath, flag: Bool) {if mMyOfflineCollectView.cellForItemAtIndexPath(indexPath) != nil {let cell = mMyOfflineCollectView.cellForItemAtIndexPath(indexPath) as! MyOfflineCollectionViewCellcell.setSelect(flag)if flag {mMyOfflineCollectView.selectItemAtIndexPath(indexPath, animated: true, scrollPosition: UICollectionViewScrollPosition.None)}else {mMyOfflineCollectView.deselectItemAtIndexPath(indexPath, animated: true)}mMyofflinesData[indexPath.row].needDelete = flag}
}

View Code

But, The problem is , I can only select the visible cell when I scoll down or up, or do operations

Solutions in NetWork

UICollectionView cellForItemAtIndexPath is nil

cellForItemAtIndexPath returns nil after force scrolling to make it visible

Select all the cells in UITableView

Easier way to select all rows in UITableView

tableView.cellForRowAtIndexPath returns nil with too many cells (swift)

tableView.cellForRowAtIndexPath(indexPath) return nil

The real Solution

The real problem happened at the cellForRowAtIndexPath / cellForItemAtIndexPath, Which defined in Apple as follows:

public func cellForRowAtIndexPath(indexPath: NSIndexPath) -> UITableViewCell?
// returns nil if cell is **not visible** or index path is out of range

public func cellForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewCell?

When the cell is not visible, the cellForRowAtIndexPath will return nil,
So, it’s not the right way to do the cell select operation out the
UITableViewDataSource in cellForRowAtIndexPath (UITabView), you should do it separate. The right way as follows:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {let cell = tableView.dequeueReusableCellWithIdentifier(DOWNLOAD_LIST_CELL_INDENTIFIER, forIndexPath: indexPath) as! DownloadListViewCellcell.selectionStyle = UITableViewCellSelectionStyle.None        // ...  cell.setSelectForDelete(self.mDownloadList[indexPath.row].selectToDelete)// select status UI in UITabViewCell// ...return cell
}private func selectCell(indexPath : NSIndexPath, select: Bool) {mDownloadList[indexPath.row].selectToDelete = select // Pojo datamListTableView?.reloadData() // reloadData
}

Ref

UITableView

UICollectionView

SYNC POST

========

By SkySeraph-2016 www.skyseraph.com

转载于:https://www.cnblogs.com/skyseraph/p/5652131.html

【iOS】UITabView/UICollectionView 全选问题相关推荐

flutter 全选_Flutter ios 国际化(复制粘贴中英文切换等问题)
前提在做flutter ios 国际化的时候遇到长按文本框崩溃的问题,然后google到一堆写法是重写cupertinoLocalization的奇怪做法,然后还千篇一律都是这么改的,其实不用那么麻 ...
ios13全选手势_独家整理！20个iOS 13使用技巧和隐藏功能，让你的iPhone更好用
iOS 13使用技巧汇总控制中心快速切换蓝牙设备和WiFi 以往控制中心只能允许用户开启/关闭WiFi或者蓝牙功能,而在iOS 13系统中,只需长按蓝牙.WiFi图标,即可快速打开对应的列表,并进行快 ...
ios非常全的库iOS开发非常全的三方库、插件、大牛博客等等
转自: TimLiu-iOS Swift版本点击这里欢迎加入交QQ流群: 594119878 github排名 https://github.com/trending,github搜索:https:/ ...
iOS：iOS开发非常全的三方库、插件、大牛博客等等
iOS开发非常全的三方库.插件.大牛博客等等 github排名:https://github.com/trending, github搜索:https://github.com/search. 此文章 ...
JavaScript基础12-day14【DOM查询(获取元素节点、获取元素节点的子节点)、全选练习、DOM增删改、DOM添加删除记录、Window对象方法】
学习地址: 谷粒学院--尚硅谷哔哩哔哩网站--尚硅谷最新版JavaScript基础全套教程完整版(140集实战教学,JS从入门到精通) JavaScript基础.高级学习笔记汇总表[尚硅谷最新版Ja ...
iphone复制不能全选_iphone长按键盘进行复制、粘贴、全选操作技巧
您可能感兴趣的话题: 苹果核心提示:可能你已经不记得,但以前 iOS 并没有复制贴上功能.后来 Apple 终于想到一个方法将这功能放入 iOS -- 长按文字.这个方法的确十分简单易用,不过对于想 ...
模拟购物车页面全选单选的金额累加
1.前面部分的内容就不过多说明了,就是OkGo请求数据然后封装适配器加入数据源,先上代码先上适配器的代码,注意这里使用的万能适配器,加入依赖 implementation 'com.github.C ...
iphone复制不能全选_IOS默认全选复制的三种方案
类似于textField,长按就会默认跳出复制的选项,但是默认选中的就是你手指点击的那个文字,想全选的话必须手动选择全选才可以,而最近碰到一个需求就是要点击文字,默认就是选中所有的文字,比如游戏中的邀 ...
好用的下拉选框（单选，多选，全选，清空和反选，及个种样式）----个人钟爱
下拉选框如需样例和具体效果,请点击下面的连接. 好用的下拉选框(单选,多选,全选,清空和反选,及个种样式) 附件一:layui应用formselect layui.config({base: './ ...

【iOS】UITabView/UICollectionView 全选问题

UITabView/UICollectionView 全选问题

The Issue

Solutions in NetWork

The real Solution

Ref

【iOS】UITabView/UICollectionView 全选问题相关推荐

最新文章

热门文章