目前我的ActionSheet遇到了大麻烦。在iPhone上它运行良好，但在iPad上它只会崩溃
我用一个按钮创建一个新项目
import UIKit
extension ViewController : UIActionSheetDelegate {
func actionSheet(actionSheet: UIActionSheet, didDismissWithButtonIndex buttonIndex: Int) {
if actionSheet.tag == 0 {
if buttonIndex == 1 {
// doing something for "product page"
} else if (buttonIndex == 2) {
// doing something for "video"
}
}
}
}
class ViewController: UIViewController, UIActionSheetDelegate {
@IBAction func test(sender: AnyObject) {
let systemVersion: NSInteger = (UIDevice.currentDevice().systemVersion as NSString).integerValue
if systemVersion < 8 {
// iOS7:
let action:UIActionSheet = UIActionSheet(title: "Change Map Type", delegate: self, cancelButtonTitle: "Back", destructiveButtonTitle: nil, otherButtonTitles: "Product Page", "Video")
action.tag = 0
action.showInView(self.view)
} else {
// iOS8:
let alertController: UIAlertController = UIAlertController(title: "Change Map Type", message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)
let cancelAction: UIAlertAction = UIAlertAction(title: "Back", style: UIAlertActionStyle.Cancel, handler: nil)
let button1action: UIAlertAction = UIAlertAction(title: "Product Page", style: UIAlertActionStyle.Default, handler: { (action: UIAlertAction!) -> () in
// doing something for "product page"
})
let button2action: UIAlertAction = UIAlertAction(title: "Video", style: UIAlertActionStyle.Default, handler: { (action: UIAlertAction!) -> () in
// doing something for "video"
})
alertController.addAction(cancelAction)
alertController.addAction(button1action)
alertController.addAction(button2action)
self.presentViewController(alertController, animated: true, completion: nil)
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
}
正如我在iphone上说的那样，但是如果我点击iPad上的按钮那么应用就会崩溃
2014-09-25 14：54：52.784 test [9541：1970048] *由于未捕获的异常'NSGenericException'而终止应用程序，原因是：'您的应用程序已呈现样式UIAlertControllerStyleActionSheet的UIAlertController（）。具有此样式的UIAlertController的modalPresentationStyle是UIModalPresentationPopover。您必须通过警报控制器的popoverPresentationController为此弹出窗口提供位置信息。您必须提供sourceView和sourceRect或barButtonItem。如果在显示警报控制器时不知道此信息，您可以在UIPopoverPresentationControllerDelegate方法-prepareForPopoverPresentation中提供它。 *第一次抛出调用堆栈：（0 CoreFoundation 0x00613df6 exceptionPreprocess + 182 1 libobjc.A.dylib 0x01fdaa97 objc_exception_throw + 44 2 UIKit 0x0164da37 - [UIPopoverPresentationController presentationTransitionWillBegin] + 3086 3 UIKit 0x00f54f75 __71- [UIPresentationController _initViewHierarchyForPresentationSuperview：] _ block_invoke + 1666 4 UIKit 0x00f53554 __56- [UIPresentationController runTransitionForCurrentState] _block_invoke + 226 5 UIKit 0x00f8721b __40 + [UIViewController _scheduleTransition：] _ block_invoke + 18 6 UIKit 0x00e4d62e ___afterCACommitHandler_block_invoke + 15 7 UIKit 0x00e4d5d9 _applyBlockToCFArrayCopiedToStack + 415 8 UIKit 0x00e4d3ee _afterCACommitHandler + 545 9 CoreFoundation 0x00536fbe __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION + 30 10 CoreFoundation 0x00536f00 __CFRunLoopDoObservers + 400 11 CoreFoundation 0x0052c93a __CFRunLoopRun + 1226 12 CoreFoundation 0x0052c1ab CFRunLoopRunSpecific + 443 13 CoreFoundation 0x0052bfdb CFRunLoopRunInMode + 123 14 GraphicsServices 0x0438424f GSEventRunModal + 192 15 GraphicsServices 0x0438408c GSEventRun + 104 16 UIKit 0x00e23e16 UIApplicationMain + 1526 17测试 0x00085e9e top_level_code + 78 18测试 0x00085edb main + 43 19 libdyld.dylib 0x0273eac9开始+ 1 20 ??? 0x00000001 0x0 + 1）libc ++ abi.dylib：以NSException类型的未捕获异常终止
项目可以在https://www.dropbox.com/s/54jqd8nsc67ll5g/test.zip?dl=0下载并试用。
错误消息告诉您需要为警报控制器的popoverPresentationController提供一个位置，以便它可以正确定位。这很容易做 - 只需检查是否有弹出控制器并将发件人添加为源。
如果您的按钮是UIBarButtonItem：
if let popoverController = alertController.popoverPresentationController {
popoverController.barButtonItem = sender
}
self.presentViewController(alertController, animated: true, completion: nil)
除此以外：
if let popoverController = alertController.popoverPresentationController {
popoverController.sourceView = sender
popoverController.sourceRect = sender.bounds
}
self.presentViewController(alertController, animated: true, completion: nil)
试试这个
alertController.popoverPresentationController?.sourceView = self.view
Nate Cook是完全正确但我会这样做，所以我发现它是iPad还是iPhone。
这是为barButtonItem：
if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad ){
if let currentPopoverpresentioncontroller = alertController.popoverPresentationController{
currentPopoverpresentioncontroller.barButtonItem = sender as! UIBarButtonItem
currentPopoverpresentioncontroller.permittedArrowDirections = UIPopoverArrowDirection.down;
self.present(alertController, animated: true, completion: nil)
}
}else{
self.present(alertController, animated: true, completion: nil)
}
如果你想在iPad上显示它没有箭头[Swift 3+]：
if let popoverController = alertController.popoverPresentationController {
popoverController.sourceView = self.view
popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)
popoverController.permittedArrowDirections = []
}
self.present(alertController, animated: true, completion: nil)
var actionSheet = UIAlertController(title: "Please Select Camera or Photo Library", message: "", preferredStyle: .actionSheet)
if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad ){
actionSheet = UIAlertController(title: "Please Select Camera or Photo Library", message: "", preferredStyle: .alert)
}
actionSheet.addAction(UIAlertAction(title: "Upload a Photo", style: .default, handler: { (UIAlertAction) in
self.openPhotoLibrary()
}))
actionSheet.addAction(UIAlertAction(title: "Take a Photo", style: .default, handler: { (UIAlertAction) in
self.openCamera()
}))
actionSheet.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(actionSheet, animated: true, completion: nil)
如果有人使用发件人：UITapGestureRecognizer，这可能会有所帮助。
@objc func popupSettings(sender : UITapGestureRecognizer) {
.....
if let popoverPresentationController = alert.popoverPresentationController {
popoverPresentationController.sourceView = self.view
popoverPresentationController.sourceRect = CGRect(origin: sender.location(in: self.view), size: CGSize(width: 1.0, height: 1.0))
}
self.present(alert, animated: true, completion: nil)
}
如果你想在中心显示你的警报而没有箭头，我尝试了这个，它适用于iOS 11.2
swift 4.2版本：
let actionSheet = UIAlertController ......
if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad ){
if let currentPopoverpresentioncontroller = actionSheet.popoverPresentationController{
currentPopoverpresentioncontroller.permittedArrowDirections = []
currentPopoverpresentioncontroller.sourceRect = CGRect(x: (self.view.bounds.midX), y: (self.view.bounds.midY), width: 0, height: 0)
currentPopoverpresentioncontroller.sourceView = self.view
self.present(actionSheet, animated: true, completion: nil)
}
}else{
self.present(actionSheet, animated: true, completion: nil)
}
Objective C版本：
UIAlertController* actionSheet
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
NSArray *empty;
UIPopoverPresentationController *currentPopOverPresentationController = [actionSheet popoverPresentationController];
currentPopOverPresentationController.permittedArrowDirections = empty;
currentPopOverPresentationController.sourceRect = CGRectMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds), 0, 0);
currentPopOverPresentationController.sourceView = self.view;
[self presentViewController:actionSheet animated:YES completion:nil];
}else{
[self presentViewController:actionSheet animated:YES completion:nil];
}