问题摘要：当UITableViewCell的UITableViewCell的高度从UITextView编辑它的文本时,当UITableView中有很多单元格时,它会崩溃.使用iOS 8自定义单元格.
长问题：我已经成功实现,所以我可以动态地使用iOS 8自定义单元格进入单元格UITextView的文本,并改变单元格高度而不失去焦点(firstReponder).但是,如果tableView太大(行数太多),则会崩溃.这是我的堆栈跟踪：
Terminating app due to uncaught exception 'NSInvalidArgumentException',reason: '*** -[__NSArrayM insertObject:atIndex:]: object cannot be nil' *** First throw call stack: ( 0 CoreFoundation 0x000000010b3b3d85 __exceptionPreprocess + 165 1 libobjc.A.dylib 0x000000010b9cbdeb objc_exception_throw + 48 2 CoreFoundation 0x000000010b274cc5 -[__NSArrayM insertObject:atIndex:] + 901 3 UIKit 0x0000000108b05439 __46-[UITableView _updateWithItems:updateSupport:]_block_invoke1029 + 180 4 UIKit 0x0000000108a7e838 +[UIView(UIViewAnimationWithBlocks) _setupAnimationWithDuration:delay:view:options:factory:animations:start:animationStateGenerator:completion:] + 582 5 UIKit 0x0000000108a7ec6d +[UIView(UIViewAnimationWithBlocks) animateWithDuration:delay:options:animations:completion:] + 105 6 UIKit 0x0000000108b05048 -[UITableView _updateWithItems:updateSupport:] + 4590 7 UIKit 0x0000000108afd5a0 -[UITableView _endCellAnimationsWithContext:] + 15360 8 Test RYM 0x0000000107e6a173 _TFE8Test_RYMCSo11UITableView31reloadDataAnimatedKeepingOffsetfT_T_ + 163 9 Test RYM 0x0000000107e6a242 _TToFE8Test_RYMCSo11UITableView31reloadDataAnimatedKeepingOffsetfT_T_ + 34 10 Test RYM 0x0000000107dcda90 _TFC8Test_RYM20AgendaViewController19cellHeightDidUpdatefTCSo11NSIndexPath6heightV12CoreGraphics7CGFloat_T_ + 144 11 Test RYM 0x0000000107dcdb04 _TToFC8Test_RYM20AgendaViewController19cellHeightDidUpdatefTCSo11NSIndexPath6heightV12CoreGraphics7CGFloat_T_ + 68 12 Test RYM 0x0000000107e725cb _TFC8Test_RYM27AgendaDecisionTableViewCell20updateTextViewHeightfT_T_ + 907 13 Test RYM 0x0000000107e731fa _TFC8Test_RYM27AgendaDecisionTableViewCell17textViewDidChangefCSo10UITextViewT_ + 42
并导致它的代码：
// In UITableView extension
func reloadDataAnimatedKeepingOffset() {
//let offset = contentOffset
//UIView.setAnimationsEnabled(false)
beginUpdates()
endUpdates()
//UIView.setAnimationsEnabled(true)
//layoutIfNeeded()
//contentOffset = offset
}
// In a self-sizing UITableViewCell subclass
func updateTextViewHeight() {
let size = decisionTextView.bounds.size
let newSize = decisionTextView.sizeThatFits(CGSize(width: size.width,height: CGFloat.max))
let newHeight = newSize.height
if size.height != newHeight {
textViewHeightConstraint.constant = newHeight
agendaViewController?.cellHeightDidUpdate(indexPath!,height: newSize.height)
}
}
// In the ViewController managing the tableView
public func cellHeightDidUpdate(indexPath: NSIndexPath,height: CGFloat) {
updateHelperAlphas()
tableView?.reloadDataAnimatedKeepingOffset()
}
它在调用endUpdates()时崩溃.我已经尝试删除tableView：estimateHeightForRowAtIndexPath：方法在UITableView insertRowsAtIndexPaths throwing __NSArrayM insertObject:atIndex:’object cannot be nil’ error中没有成功.
它似乎只发生在列表很长时间.
编辑：我使用的更多方法：
public func tableView(tableView: UITableView,estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 48.0
}
public func tableView(tableView: UITableView,heightForHeaderInSection section: Int) -> CGFloat {
if (section == 0) {
return 0
}
else {
let currentSectionIsEmpty = sectionIsEmpty(section)
if ((!isInEditProtocolMode && isProtocolMode) || isPreviousProtocolMode) && currentSectionIsEmpty {
return 0
}
let subSection = sectionHelper.subSectionForSection(section)
let isProtocolTopSection = isProtocolMode && subSection == 0
if (isProtocolTopSection) {
return UITableViewAutomaticDimension
}
else {
return agendaHeaderHeight
}
}
}
public func tableView(tableView: UITableView,estimatedHeightForHeaderInSection section: Int) -> CGFloat {
if (section == 0) {
return 0
}
else {
let subSection = sectionHelper.subSectionForSection(section)
let isProtocolTopSection = isProtocolMode && subSection == 0
if (isProtocolTopSection) {
return protocolAgendaHeaderHeight
}
else {
return agendaHeaderHeight
}
}
}
public override func viewDidLoad() {
super.viewDidLoad()
tableView.rowHeight = UITableViewAutomaticDimension
}
EDIT2：
这几乎是同样的问题. tableView crashes on end up with more than 16 items然而,我无法消除细胞高度的估计,因为这破坏了我的自动调整细胞图的动态高度.
编辑3：
尝试(从下面的评论)使用CATransaction.setDisableActions(_)和setContentOffset(_：动画:)没有任何帮助.这似乎与此无关,除了beginUpdates()和endUpdates()都没有帮助. reloadDataAnimatedKeepingOffset()似乎只被调用一次,没有其他reloadData似乎被调用在同一时间.将估计高度设置为1而不是0也没有帮助.它奇怪地显示零标题而不是高度1.
编辑4：
根据请求,我的numberOrRowsInSection和cellForRowAtIndexPath方法(有点复杂)：
public func tableView(tableView: UITableView,numberOfRowsInSection section: Int) -> Int
{
let mainSection = sectionHelper.mainSectionForSection(section)
let subSection = sectionHelper.subSectionForSection(section)
let isHeaderSection = subSection <= 0
if isHeaderSection {
return isProtocolMode ? 0 : cellIdSectionList[0].count
}
let rowType = sectionHelper.rowTypeForSection(section)
let agenda = agendaForSection(section)
switch rowType {
case .NoteRow:
return mainSectionShowingPlaceholderNewNoteCell == mainSection || !agenda.protocolString.isEmpty ? 1 : 0
case .ActionRow:
let count = max(0,agenda.actionListCount())
return count
case .DecisionRow:
var count = agenda.decisions.count ?? 0
count = max(0,count)
count = indexPathShowingPlaceholderNewDecisionCell?.section == section ? count+1 : count
return count
default:
return 0
}
}
public func tableView(tableView: UITableView,cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let row = indexPath.row
let section = indexPath.section
let cellId = cellIdForIndexPath(indexPath)
let cell = tableView.dequeueReusableCellWithIdentifier(cellId,forIndexPath: indexPath)
let allowEditing = (isInEditProtocolMode || !isProtocolMode) && !isPreviousProtocolMode
if let titleCell = cell as? StandardTitleTableViewCell {
titleCell.setup(agendaForSection(section),meeting:selectedMeeting!,indexPath:indexPath)
titleCell.delegate = self
}
if let descriptionCell = cell as? StandardDescriptionTableViewCell {
descriptionCell.setup(agendaForSection(section),indexPath: indexPath,forceExpand: hasExpandedDescriptionCellView)
descriptionCell.delegate = self
}
if let noteCell = cell as? AgendaNotesTableViewCell {
noteCell.setup(agendaForSection(section),allowEditing:allowEditing)
noteCell.agendaViewController = self
}
if let decisionCell = cell as? AgendaDecisionTableViewCell {
let decisionList = agendaForSection(section).decisions
let isNewDecisionCell = row >= decisionList.count
if !isNewDecisionCell {
let decision = decisionList[row]
decisionCell.setup(decision,allowEditing: allowEditing)
}
else {
decisionCell.setup(newDecisionToAdd!,allowEditing: allowEditing)
}
decisionCell.agendaViewController = self
}
if let actionCell = cell as? StandardTableViewCell,let actionList = agendaForSection(section).actionList {
let action = actionList.actions[row]
actionCell.setupAsActionListCell(action:action,delegate: self)
}
if let textCell = cell as? MeetingTextTableViewCell {
var placeholderText = ""
if indexPathIsActionTextPlaceholderCell(indexPath) {
placeholderText = __("agenda.noActions.text")
}
else if indexPathIsDecisionTextPlaceholderCell(indexPath) {
placeholderText = __("agenda.noDecisions.text")
}
textCell.setup(placeholderText)
}
return cell
}
public func tableView(tableView: UITableView,viewForHeaderInSection section: Int) -> UIView?
{
if (section == 0) {
return nil
}
let subSection = sectionHelper.subSectionForSection(section)
let cellId = isProtocolMode && subSection == 0 ? protocolHeaderCellId : headerCellId
let cell = tableView.dequeueReusableHeaderFooterViewWithIdentifier(cellId)
let agenda = agendaForSection(section)
if let standardHeaderCell = cell as? StandardTableViewHeaderCell {
let subSection = sectionHelper.subSectionForSection(section)
let currentSectionIsEmpty = sectionIsEmpty(section)
let protocolIsLocked = selectedMeeting!.protocolIsLocked
if (isPreviousProtocolMode && currentSectionIsEmpty) {
return nil
}
let allowEditing = (isInEditProtocolMode || !isProtocolMode) && !isPreviousProtocolMode && !protocolIsLocked
let showRightAddButton = ((subSection == 1 && currentSectionIsEmpty) || subSection == 2 || (subSection == 3 && indexPathShowingPlaceholderNewDecisionCell?.section != section)) && allowEditing
let headerTitle = headerTitleList[subSection]
standardHeaderCell.setupWithText(headerTitle,section:section,showAddButton: showRightAddButton,delegate: self)
}
else if let protocolHeaderCell = cell as? ProtocolTableViewHeaderCell {
let showSeparator = section > 1
let onlyShowAttachmentIfItHaveAttachments = isPreviousProtocolMode || (isProtocolMode && !isInEditProtocolMode)
let showAttachmentIcon = !onlyShowAttachmentIfItHaveAttachments || agenda.attachments.count > 0
protocolHeaderCell.setup(showSeparator: showSeparator,agenda: agenda,section: section,showProtocolIcon: false,showAttachmentIcon: showAttachmentIcon,delegate: self)
}
return cell!.wrappedInNewView()
}
// In UIView extension
func wrappedInNewView() -> UIView
{
let view = UIView(frame: frame)
autoresizingMask = [.FlexibleHeight,.FlexibleWidth]
view.addSubview(self)
return view
}
解决方法
这是关于这个iOS bug的雷达：
http://openradar.appspot.com/15729686
所有我建议你要做的是取代这个：
所有我建议你要做的是取代这个：
public func tableView(tableView: UITableView,estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 48.0
}
有了这个：
tableView.rowHeight = UITableViewAutomaticDimension tableView.estimatedRowHeight = 48.0
如果还是崩溃了,那么也尝试去除tableView：estimatedHeightForHeaderInSection：方法
我们应该穿过我们的手指,希望这个雷达将关闭与新的iOS X
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