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
我只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，但如果我点击iPad上的按钮应用程序崩溃了
2014-09-25 14：54：52.784 test [9541：1970048] *终止应用程序 未捕获的异常'NSGenericException'，原因：'您的应用程序有 提出了一个UIAlertController（） style UIAlertControllerStyleActionSheet。的modalPresentationStyle 具有此样式的UIAlertController是UIModalPresentationPopover。您 必须通过警报提供此弹出窗口的位置信息 controller的popoverPresentationController。你必须提供一个 sourceView和sourceRect或barButtonItem。如果这个信息是 当您出示警报控制器时不知道，您可以提供它 UIPopoverPresentationControllerDelegate方法 -prepareForPopoverPresentation“。 * 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：以未捕获终止 NSException类型的异常
可以在https://www.dropbox.com/s/54jqd8nsc67ll5g/test.zip?dl=0找到项目进行下载并尝试。
答案 0 :(得分：145)
错误消息告诉您需要向警报控制器的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)
否则：
if let popoverController = alertController.popoverPresentationController {
popoverController.sourceView = sender
popoverController.sourceRect = sender.bounds
}
self.presentViewController(alertController, animated: true, completion: nil)
答案 1 :(得分：7)
试试这个
alertController.popoverPresentationController?.sourceView = self.view
答案 2 :(得分：2)
Nate Cook是完全正确但我会这样做，所以我发现它是iPad还是iPhone。
这适用于// decimal truncation is free when dealing with int/long
long value = new Date().getTime() / 1000 / 30;
byte[] data = new byte[8];
for (int i = 8; i-- > 0; value >>>= 8) {
data[i] = (byte) value;
}
byte[] hash = hmacSha1(data, key);
：
barButtonItem答案 3 :(得分：1)
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)
答案 4 :(得分：1)
如果您想在iPad上无箭头地将其展示在屏幕上[ Swift 3 + ]：
struct EventA {};
struct EventB {};
struct EventC {};
using Event = std::variant<EventA, EventB, EventC>;
struct Visitor {
enum class LastEvent { None, A, B, C };
struct State {
LastEvent last_event = LastEvent::None;
};
static State apply(State s, EventA e) { return State{LastEvent::A}; }
static State apply(State s, EventB e) { return State{LastEvent::B}; }
};
template <typename Visitor> struct Applicator {
static State apply(State s, Event e) {
/*** Start of pseudo code ***/
if (Visitor can apply) {
return Visitor::apply(s, e);
}
/*** End of pseudo code ***/
// Else, don't update state state
return s;
}
};
int main() {
// Handled by visitor
State s1 = Applicator<Visitor>::apply(State{}, EventA{});
assert(s1.last_event == Visitor::LastEvent::A);
// Handled by visitor
State s2 = Applicator<Visitor>::apply(State{}, EventB{});
assert(s2.last_event == Visitor::LastEvent::B);
// NOT handled by visitor
State s3 = Applicator<Visitor>::apply(State{}, EventC{});
assert(s3.last_event == Visitor::LastEvent::None);
}
答案 5 :(得分：0)
如果有人使用 sender：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)
}
答案 6 :(得分：0)
如果您想在中心显示警报而没有箭头，我尝试了一下，它可以在iOS 11.2上运行
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)
}
目标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];
}
答案 7 :(得分：0)
跟进Nate Cook的回答。如果您的按钮是UIBarButtonItem，则可能有必要在sender上进行强制转换。
if let popoverController = alertController.popoverPresentationController {
popoverController.barButtonItem = sender as! UIBarButtonItem
}
self.presentViewController(alertController, animated: true, completion: nil)