在iOS 8.0中，苹果推出了UIAlertController以取代UIActionSheet.不幸的是，苹果没有添加任何关于如何展示它的信息.我在哈耶克的博客上找到了一个关于它的entry，然而，它在iPad上似乎不起作用.这种观点完全是错误的:
放错位置:
更正:
我使用以下代码在界面上显示它:
let alert = UIAlertController()
// setting buttons
self.presentModalViewController(alert, animated: true)
有没有其他方法可以把它添加到iPad上？或者苹果只是忘记了iPad，或者还没有实现？
您可以使用UIPopoverPresentationController从弹出窗口显示UIAlertController.
UIViewController *self; // code assumes you're in a view controller
UIButton *button; // the button you want to show the popup sheet from
UIAlertController *alertController;
UIAlertAction *destroyAction;
UIAlertAction *otherAction;
alertController = [UIAlertController alertControllerWithTitle:nil
message:nil
preferredStyle:UIAlertControllerStyleActionSheet];
destroyAction = [UIAlertAction actionWithTitle:@"Remove All Data"
style:UIAlertActionStyleDestructive
handler:^(UIAlertAction *action) {
// do destructive stuff here
}];
otherAction = [UIAlertAction actionWithTitle:@"Blah"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
// do something here
}];
// note: you can control the order buttons are shown, unlike UIActionSheet
[alertController addAction:destroyAction];
[alertController addAction:otherAction];
[alertController setModalPresentationStyle:UIModalPresentationPopover];
UIPopoverPresentationController *popPresenter = [alertController
popoverPresentationController];
popPresenter.sourceView = button;
popPresenter.sourceRect = button.bounds;
[self presentViewController:alertController animated:YES completion:nil];
编辑SWIFT 4.2，虽然有很多博客可以提供相同的内容，但go 搜索它们可能会节省您的时间.
if let popoverController = yourAlert.popoverPresentationController {
popoverController.sourceView = self.view //to set the source of your alert
popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0) // you can set this as per your requirement.
popoverController.permittedArrowDirections = [] //to hide the arrow of any particular direction
}