如何在点击 UIAlertController
以外的区域时关闭它?
我可以添加一个样式为UIAlertActionStyleCancel
的UIAlertAction
来关闭UIAlertController
。
但是,我想要添加一个功能,当用户点击 UIAlertController
以外的区域时,UIAlertController
也能够关闭。怎么做呢?谢谢。
如何在点击 UIAlertController
以外的区域时关闭它?
我可以添加一个样式为UIAlertActionStyleCancel
的UIAlertAction
来关闭UIAlertController
。
但是,我想要添加一个功能,当用户点击 UIAlertController
以外的区域时,UIAlertController
也能够关闭。怎么做呢?谢谢。
添加一个带有样式 UIAlertActionStyleCancel
的独立取消操作,以便当用户点击外部时,可以获得回调。
Obj-c
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Alert Title" message:@"A Message" preferredStyle:UIAlertControllerStyleActionSheet];
[alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
// Called when user taps outside
}]];
Swift 5.0
let alertController = UIAlertController(title: "Alert Title", message: "A Message", preferredStyle: .actionSheet)
alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: {
action in
// Called when user taps outside
}))
如果你的目标设备运行iOS > 9.3,并使用Swift,同时preferredStyle为Alert,你可以使用以下代码片段:
let alert = UIAlertController(title: "Title", message: "Message", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
present(alert, animated: true, completion: nil)
func showAlertBtnClicked(sender: UIButton) {
let alert = UIAlertController(title: "This is title", message: "This is message", preferredStyle: .Alert)
self.presentViewController(alert, animated: true, completion:{
alert.view.superview?.userInteractionEnabled = true
alert.view.superview?.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.alertControllerBackgroundTapped)))
})
}
func alertControllerBackgroundTapped()
{
self.dismissViewControllerAnimated(true, completion: nil)
}
使用Swift 3:
func showAlertBtnClicked(sender: UIButton) {
let alert = UIAlertController(title: "This is title", message: "This is message", preferredStyle: .alert)
self.present(alert, animated: true) {
alert.view.superview?.isUserInteractionEnabled = true
alert.view.superview?.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.alertControllerBackgroundTapped)))
}
}
func alertControllerBackgroundTapped()
{
self.dismiss(animated: true, completion: nil)
}
alert.view.superview.subviews[1]
)的第二个子视图上,而不是超级视图本身。正如文档中所述,UIAlertController的视图层次结构是私有的,因此不能保证它在未来的iOS发布中不会改变。 - Thanh Phamalert.view.superview
及其所有subviews
中。目前它可以工作,适用于iOS 11.2! - FonzTechalertControllerBackgroundTapped
函数添加@objc
,否则Xcode会解释。除此之外,Swift 3版本也适用于Swift 5,谢谢。 - Neph为你的 alertController 提供一个 action,其中 UIAlertAction
的样式是 .cancel
。
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)
alertController.addAction(cancelAction)
使用此方法,当用户点击取消操作按钮或 alertController 外部时,alertController 将被关闭。
如果您不希望用户在触摸 alertController 之外后关闭 alertController,请在 present 方法的完成闭包中禁用 alertController 的第一个子视图的用户交互。
self.present(alertController, animated: true) {
alertController.view.superview?.subviews[0].isUserInteractionEnabled = false
}
如果您不想在控制器视图中显示取消按钮,并希望在用户在控制器视图外部触摸时关闭控制器,请这样做。
self.present(alertController, animated: true) {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.dismissAlertController))
alertController.view.superview?.subviews[0].addGestureRecognizer(tapGesture)
}
@objc func dismissAlertController(){
self.dismiss(animated: true, completion: nil)
}
如果你正在使用 Swift :
使用addAction(_:)
和 style:UIAlertActionStyle.Cancel
添加一个操作。
当你点击按钮或框架外部时,将调用 `handler`。
var alertVC = UIAlertController(...) // initialize your Alert View Controller
alertVC.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: {
(alertAction: UIAlertAction!) in
alertVC.dismissViewControllerAnimated(true, completion: nil)
}))
Objective-C :
目标-C:UIAlertController *alertController = [UIAlertController alertControllerWithTitle:...];
[alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
[alertVC dismissViewControllerAnimated:YES completion:nil];
}]];
UIAlertActionStyle
。在这个例子中,我将按钮设置为 Cancel
样式。你可以将它设置为 Default
。 - Kevin MachadoSwift 4:
当用户点击 UIAlertController 创建的 Action Sheet 外部时,关闭 Action Sheet。
代码片段:
// Declare Action Sheet reference
var actionSheet: UIAlertController!
// Init and Show Action Sheet
func showActionSheetClicked(sender: UIButton) {
// Init Action Sheet
actionSheet = UIAlertController(title: "Title", message: "Message", preferredStyle: .actionSheet)
self.present(actionSheet, animated: true) {
// Enabling Interaction for Transperent Full Screen Overlay
self.actionSheet.view.superview?.subviews.first?.isUserInteractionEnabled = true
// Adding Tap Gesture to Overlay
self.actionSheet.view.superview?.subviews.first?.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.actionSheetBackgroundTapped)))
}
}
// To dismiss Action Sheet on Tap
@objc func actionSheetBackgroundTapped() {
self.actionSheet.dismiss(animated: true, completion: nil)
}
- (void)addBackgroundDismissTapForAlert:(UIAlertController *)alert {
if (!alert.view.superview) {
return;
}
alert.view.superview.userInteractionEnabled = YES;
[alert.view.superview addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(alertControllerBackgroundTapped)]];
for (UIView *subV in alert.view.superview.subviews) {
if (subV.width && subV.height) {
subV.userInteractionEnabled = YES;
[subV addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(alertControllerBackgroundTapped)]];
}
}
}
- (void)alertControllerBackgroundTapped {
[self dismissViewControllerAnimated: YES
completion: nil];
}
在 Obj-C 中最简单的方法:
UIAlertController *alert = [UIAlertController alertControllerWithTitle: ...
[self presentViewController:alert animated:YES completion:^{
[alert.view.superview addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(alertControllerBackgroundTapped)]];
}];
然后:
- (void)alertControllerBackgroundTapped
{
[self dismissViewControllerAnimated: YES
completion: nil];
}
如果您查看警告框的父视图进行调试,您会发现它并不像在_UIAlertControllerView的UITransitionView上添加一个轻拍手势识别器那么简单。相反,您可以这样做。
[presenter presentViewController:alertController animated:YES completion:^{
NSArray <UIView *>* superviewSubviews = alertController.view.superview.subviews;
for (UIView *subview in superviewSubviews) {
if (CGRectEqualToRect(subview.bounds, weakSelf.view.bounds)) {
[subview addSingleTapGestureWithTarget:weakSelf action:@selector(dismissModalTestViewController)];
}
}
}];
UIAlertController
的视图层次结构似乎又一次发生了变化。它被呈现为一个包含控制器本身的新UIWindow
。因此,为了在点击外部时关闭它:present(alertController, animated: true) { [weak self] in
guard let self = self else { return }
let dismissGesture = UITapGestureRecognizer(target: self, action: #selector(self.shouldDismiss))
self.alertController.view.window?.isUserInteractionEnabled = true
self.alertController.view.window?.addGestureRecognizer(dismissGesture)
}
对于shouldDismiss
函数:
@objc private func shouldDismiss() {
alertController.dismiss(animated: true)
}
UIView *alertView = self.alertController.view;
UIView *superPuperView = self.alertController.view.superview;
CGPoint tapCoord = [tap locationInView:superPuperView];
if (!CGRectContainsPoint(alertView.frame, tapCoord)) {
//dismiss alert view
}