在iOS 8.0中,苹果引入了UIAlertController来取代UIActionSheet。不幸的是,苹果没有提供任何关于如何展示的信息。我在hayaGeek的博客上找到了一个关于它的条目,然而,它似乎不能在iPad上运行。这种观点是完全错误的:
错误的:
正确的:
我使用以下代码在界面上显示它:
let alert = UIAlertController()
// setting buttons
self.presentModalViewController(alert, animated: true)
是否有其他方法添加到iPad上?或者苹果只是忘记了iPad,或者还没有推出iPad ?
你可以通过使用UIPopoverPresentationController从弹窗中呈现一个UIAlertController。
在Obj-C:
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];
Swift 4.2的编辑,虽然有很多博客可用,但它可以节省你的时间去搜索他们。
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
}
Swift 3.0及更高版本更新
let actionSheetController: UIAlertController = UIAlertController(title: "SomeTitle", message: nil, preferredStyle: .actionSheet)
let editAction: UIAlertAction = UIAlertAction(title: "Edit Details", style: .default) { action -> Void in
print("Edit Details")
}
let deleteAction: UIAlertAction = UIAlertAction(title: "Delete Item", style: .default) { action -> Void in
print("Delete Item")
}
let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .cancel) { action -> Void in }
actionSheetController.addAction(editAction)
actionSheetController.addAction(deleteAction)
actionSheetController.addAction(cancelAction)
// present(actionSheetController, animated: true, completion: nil) // doesn't work for iPad
actionSheetController.popoverPresentationController?.sourceView = yourSourceViewName // works for both iPhone & iPad
present(actionSheetController, animated: true) {
print("option menu presented")
}
它将同时适用于iphone和ipad
func showImagePicker() {
var alertStyle = UIAlertController.Style.actionSheet
if (UIDevice.current.userInterfaceIdiom == .pad) {
alertStyle = UIAlertController.Style.alert
}
let alert = UIAlertController(title: "", message: "Upload Attachment", preferredStyle: alertStyle)
alert.addAction(UIAlertAction(title: "Choose from gallery", style: .default , handler:{ (UIAlertAction) in
self.pickPhoto(sourceType: .photoLibrary)
}))
alert.addAction(UIAlertAction(title: "Take Photo", style: .default, handler:{ (UIAlertAction) in
self.pickPhoto(sourceType: .camera)
}))
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler:{ (UIAlertAction) in
}))
present(alert, animated: true, completion: nil)
}
Swift 4及以上
我已经创建了一个扩展
extension UIViewController {
public func addActionSheetForiPad(actionSheet: UIAlertController) {
if let popoverPresentationController = actionSheet.popoverPresentationController {
popoverPresentationController.sourceView = self.view
popoverPresentationController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)
popoverPresentationController.permittedArrowDirections = []
}
}
}
使用方法:
let actionSheetVC = UIAlertController(title: "Title", message: nil, preferredStyle: .actionSheet)
addActionSheetForiPad(actionSheet: actionSheetVC)
present(actionSheetVC, animated: true, completion: nil)