在iOS8中的Popover中呈现UIAlertController

本文介绍了在iOS8中的Popover中呈现UIAlertController的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我设置一个UITableViewController在iPad上的弹出框中显示：

当我点击一行时，我会显示一条警告，警告用户可能存在破坏性行为。 我使用了新的UIAlertController，接下来会发生什么：

弹出窗口变得非常小（实际上是alertController视图的大小）。如果我按下取消，我可以看到结果： <这是我的代码：

覆盖func tableView（tableView：UITableView） ，didSelectRowAtIndexPath indexPath：NSIndexPath）{ var previousSelectedCell：UITableViewCell？ if checkedIndexPath！= nil { previousSelectedCell = tableView.cellForRowAtIndexPath（checkedIndexPath）} var selectedCell = tableView.cellForRowAtIndexPath（indexPath） let selectedCurrency = PortfolioCurrencyStore.sharedStore（）。allCurrencies [indexPath.row] 如果selectedCurrency.symbol！= GlobalSettings.sharedStore（）。portfolioCurrency { //警告：更改投资组合货币将重置投资组合 var resetWarning = UIAlertController（标题：NSLocalizedString（货币选择器VC：AS标题，评论：更改货币将重置投资组合），消息：nil，preferredStyle：.ActionSheet） //破坏性按钮 let resetAction = UIAlertAction（标题：NSLocalizedString（货币选择器VC：AS破坏性，评论：破坏性按钮标题），样式：.Destructive，handler：{（action ：UIAlertAction！）in //从上一页删除复选标记标记为单元格 previousSelectedCell？.accessoryType = .None //为所选单元格添加复选标记 selectedCell？.accessoryType = .Checkmark self.checkedIndexPath = indexPath //单元格的动画取消选择 self.tableView.deselectRowAtIndexPath（indexPath，animated：true） //将投资组合货币作为NSUserDefaults 存货GlobalSettings.sharedStore（）。portfolioCurrency = selectedCurrency.symbol //将portfolioCurrency作为String链接，将currency.symbol作为Currency实例的属性进行链接。 //删除StockStore中的所有商品 StockStore.sharedStore（）。removeAllStocks（） println（StockStore：所有条目都被删除） //重新加载tableView self.tableView.reloadData（） }） //取消按钮 let cancelAction = UIAlertAction（标题：NSLocalizedString（货币选择器VC：AS取消，注释：取消按钮标题），样式：.Cancel，handler：nil） resetWarning.addAction（resetAction） resetWarning.addAction（cancelAction） presentViewController（resetWarning，animated：true，completion：nil） } else { //取消选择单元格 tableView.deselectRowAtIndexPath（indexPath，animated：true）} }

我错过了什么吗？

感谢您的帮助

解决方案

找到它！ 如果此AlertController出现在一个popover中，它必须提供位置信息，sourceView和sourceRect，或barButtonItem。

喜欢

resetWarning.popoverPresentationController？.sourceView = selectedCell？.contentView resetWarning.popoverPresentationController？.sourceRect = selectedCell ！.contentView.frame

我的代码必须如此：

覆盖func tableView（tableView：UITableView，didSelectRowAtIndexPath indexPath：NSIndexPath）{ var previousSelectedCell：UITableViewCell？ if checkedIndexPath！= nil { previousSelectedCell = tableView.cellForRowAtIndexPath（checkedIndexPath）} var selectedCell = tableView.cellForRowAtIndexPath（indexPath） let selectedCurrency = PortfolioCurrencyStore.sharedStore.allCurrencies [indexPath.row] if selectedCurrency.symbol！= GlobalSettings.sharedStore.portfolioCurrency { //警告：更改投资组合货币将重置组合 var resetWarning = UIAlertController（标题：NSLocalizedString（货币选择器VC：AS标题，评论：更改货币将重置投资组合），消息：nil，preferredStyle：.ActionSheet） //破坏性按钮 let resetAction = UIAlertAction（标题：NSLocalizedString（货币选择器VC：AS破坏性，评论：破坏性按钮标题），样式：。破坏性，处理程序：{（动作：UIAlertAction！） in //删除previousl的复选标记y标记单元格 previousSelectedCell？.accessoryType = .None //为所选单元格添加复选标记 selectedCell？.accessoryType = .Checkmark self.checkedIndexPath = indexPath //单元格的动画取消选择 self.tableView.deselectRowAtIndexPath（indexPath，animated：true） //将投资组合货币作为NSUserDefaults 存货GlobalSettings.sharedStore.portfolioCurrency = selectedCurrency.symbol //将portfolioCurrency作为String链接，将currency.symbol作为Currency实例的属性进行链接。 //删除StockStore中的所有商品 StockStore.sharedStore.removeAllStocks（） println（StockStore：所有条目都被删除） //从CurrencyRateStore中删除所有项目 CurrencyRateStore.sharedStore.deleteAllRates（） println（CurrencyStore：删除所有条目） //从SalesJournal中删除所有项目 SalesJournal.sharedStore.removeAllEntries（） println（SalesJournal：所有销售日记帐分录都已删除） //重新加载tableView self。 tableView.reloadData（） //在普通尺寸上，货币选择器显示在一个弹出框内：列表视图的reloadData NSNotificationCenter.defaultCenter（）。postNotificationName（CurrencyPickerVC_PortfolioCurrencyDidChangeNotification，对象：nil，userInfo：nil） / / Animate取消选择单元格 tableView.deselectRowAtIndexPath（indexPath，animated：true） //返回根目录VC self.navigationController？.popToRootViewControllerAnimated（true） }） //取消按钮让cancelAction = UIAlertAction（标题：NSLocalizedString（货币选择器VC：AS取消，评论： 取消按钮标题），样式：。取消，处理程序：{（alertAction：UIAlertAction！） - >无效 // Animate取消选择单元 self.tableView.deselectRowAtIndexPath（indexPath，animated：true）}） resetWarning.addAction（resetAction） resetWarning.addAction（cancelAction） //如果此AlertController出现在弹出窗口内，它必须提供位置信息，sourceView和sourceRect或barButtonItem。 resetWarning.popoverPresentationController？.sourceView = selectedCell？.contentView resetWarning.popoverPresentationController？.sourceRect = selectedCell！.contentView.frame presentViewController（resetWarning，animated：true，completion： nil） } else { // Animate取消选择单元 tableView.deselectRowAtIndexPath（indexPath，animated：true）} }

现在图片如下所示：

I set a UITableViewController to be displayed in a popover on iPad :

When I click on a row, I display an alert to warn the user of a potential destructive action. I used the new UIAlertController, and here is what happens:

The popover becomes very small (the size of the alertController view in fact). If I press Cancel, I can see the result :

Here is my code:

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { var previouslySelectedCell: UITableViewCell? if checkedIndexPath != nil { previouslySelectedCell = tableView.cellForRowAtIndexPath(checkedIndexPath) } var selectedCell = tableView.cellForRowAtIndexPath(indexPath) let selectedCurrency = PortfolioCurrencyStore.sharedStore().allCurrencies[indexPath.row] if selectedCurrency.symbol != GlobalSettings.sharedStore().portfolioCurrency { // Warning : changing the portfolio currency will reset the portfolio var resetWarning = UIAlertController(title: NSLocalizedString("Currency Picker VC:AS title", comment: "Changing currency will reset portfolio"), message: nil, preferredStyle: .ActionSheet) // destructive button let resetAction = UIAlertAction(title: NSLocalizedString("Currency Picker VC:AS destructive", comment: "Destructive button title"), style: .Destructive, handler: { (action: UIAlertAction!) in // Remove checkmark from the previously marked cell previouslySelectedCell?.accessoryType = .None // Add checkmark to the selected cell selectedCell?.accessoryType = .Checkmark self.checkedIndexPath = indexPath // Animate deselection of cell self.tableView.deselectRowAtIndexPath(indexPath, animated:true) // Stock the portfolio currency as NSUserDefaults GlobalSettings.sharedStore().portfolioCurrency = selectedCurrency.symbol // link between portfolioCurrency as a String and currency.symbol as the property of a Currency instance. // Delete all items from the StockStore StockStore.sharedStore().removeAllStocks() println("StockStore : all entries were deleted") // Reload tableView self.tableView.reloadData() }) // cancel button let cancelAction = UIAlertAction(title: NSLocalizedString("Currency Picker VC:AS cancel", comment: "Cancel button title"), style: .Cancel, handler:nil) resetWarning.addAction(resetAction) resetWarning.addAction(cancelAction) presentViewController(resetWarning, animated: true, completion: nil) } else { // Animate deselection of cell tableView.deselectRowAtIndexPath(indexPath, animated:true) } }

Did I miss something ?

Thanks for your help

解决方案

Found it ! If this AlertController is presented inside a popover, it must provide the location information, either a sourceView and sourceRect, or a barButtonItem.

Like

resetWarning.popoverPresentationController?.sourceView = selectedCell?.contentView resetWarning.popoverPresentationController?.sourceRect = selectedCell!.contentView.frame

My code had to look like that:

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { var previouslySelectedCell: UITableViewCell? if checkedIndexPath != nil { previouslySelectedCell = tableView.cellForRowAtIndexPath(checkedIndexPath) } var selectedCell = tableView.cellForRowAtIndexPath(indexPath) let selectedCurrency = PortfolioCurrencyStore.sharedStore.allCurrencies[indexPath.row] if selectedCurrency.symbol != GlobalSettings.sharedStore.portfolioCurrency { // Warning : changing the portfolio currency will reset the portfolio var resetWarning = UIAlertController(title: NSLocalizedString("Currency Picker VC:AS title", comment: "Changing currency will reset portfolio"), message: nil, preferredStyle: .ActionSheet) // destructive button let resetAction = UIAlertAction(title: NSLocalizedString("Currency Picker VC:AS destructive", comment: "Destructive button title"), style: .Destructive, handler: { (action: UIAlertAction!) in // Remove checkmark from the previously marked cell previouslySelectedCell?.accessoryType = .None // Add checkmark to the selected cell selectedCell?.accessoryType = .Checkmark self.checkedIndexPath = indexPath // Animate deselection of cell self.tableView.deselectRowAtIndexPath(indexPath, animated:true) // Stock the portfolio currency as NSUserDefaults GlobalSettings.sharedStore.portfolioCurrency = selectedCurrency.symbol // link between portfolioCurrency as a String and currency.symbol as the property of a Currency instance. // Delete all items from the StockStore StockStore.sharedStore.removeAllStocks() println("StockStore : all entries were deleted") // Delete all items from the CurrencyRateStore CurrencyRateStore.sharedStore.deleteAllRates() println("CurrencyStore : all entries were deleted") // Delete all items from the SalesJournal SalesJournal.sharedStore.removeAllEntries() println("SalesJournal : all Sales journal entries were deleted") // Reload tableView self.tableView.reloadData() // On Regular sizes, the currency picker is presented inside a popover : reloadData of the List View NSNotificationCenter.defaultCenter().postNotificationName("CurrencyPickerVC_PortfolioCurrencyDidChangeNotification", object:nil, userInfo:nil) // Animate deselection of cell tableView.deselectRowAtIndexPath(indexPath, animated:true) // Return to root VC self.navigationController?.popToRootViewControllerAnimated(true) }) // cancel button let cancelAction = UIAlertAction(title: NSLocalizedString("Currency Picker VC:AS cancel", comment: "Cancel button title"), style: .Cancel, handler: { (alertAction: UIAlertAction!) -> Void in // Animate deselection of cell self.tableView.deselectRowAtIndexPath(indexPath, animated:true) }) resetWarning.addAction(resetAction) resetWarning.addAction(cancelAction) // If this AlertController is presented inside a popover, it must provide the location information, either a sourceView and sourceRect or a barButtonItem. resetWarning.popoverPresentationController?.sourceView = selectedCell?.contentView resetWarning.popoverPresentationController?.sourceRect = selectedCell!.contentView.frame presentViewController(resetWarning, animated: true, completion: nil) } else { // Animate deselection of cell tableView.deselectRowAtIndexPath(indexPath, animated:true) } }

Now the image looks like this: