如何在 UIBarbutton 中将 UIAlertcontroller 实现为 PopOver（箭头方向向上）

Question

我知道这是老派问题 - 但我确实搜索了网络并找到了要弃用的解决方案。我如何在 barButton 中将 UIAlertcontroller 实现为 popOver（箭头向上）。代码如下：

 - (IBAction)eventSortingAction:(UIBarButtonItem *)sender {

UIAlertController * view=   [UIAlertController
                         alertControllerWithTitle:@"My Title"
                         message:@"Select you Choice"
                         preferredStyle:UIAlertControllerStyleActionSheet];

UIAlertAction* ok = [UIAlertAction
                 actionWithTitle:@"OK"
                 style:UIAlertActionStyleDefault
                 handler:^(UIAlertAction * action) {
                     //Do some thing here
                     [view dismissViewControllerAnimated:YES completion:nil];

                 }];
UIAlertAction* cancel = [UIAlertAction
                     actionWithTitle:@"Cancel"
                     style:UIAlertActionStyleCancel
                     handler:^(UIAlertAction * action) {
                         [view dismissViewControllerAnimated:YES completion:nil];

                     }];
[view addAction:ok];
[view addAction:cancel];
[view setModalPresentationStyle:UIModalPresentationPopover];
view.modalInPopover = YES;
view.popoverPresentationController.permittedArrowDirections = UIPopoverArrowDirectionUp;
view.popoverPresentationController.delegate = self;
[self presentViewController:view animated:YES completion:nil];

UIView* senderView = [sender valueForKey:@"view"]; //HACK
UIPopoverPresentationController* popover = view.popoverPresentationController;
if (popover) {
   popover.sourceView = senderView;
   popover.sourceRect = senderView.bounds;
   popover.permittedArrowDirections = UIPopoverArrowDirectionUp;
   popover.barButtonItem = self.actionBarButton;
   popover.delegate = self;
}}

显然我总是得到一个“popover = nil”。请帮忙！提前致谢！

顺便说一下，这段代码不是我的，只是在 Xcode 中测试。

Answer 1

提醒一下，因为这是 Google 上的最高搜索结果：

popPresenter.barButtonItem 是 popPresenter.sourceView+popPresenter.sourceRect 的替代

See(source)

关于OP问题，应该使用IBAction参数sender。

UIPopoverPresentationController *popPresenter = [alertController
                                             popoverPresentationController];
popPresenter.barButtonItem = sender;
[self presentViewController:alertController animated:YES completion:nil];

Answer 2

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil
                                                                         message:nil
                                                                  preferredStyle:UIAlertControllerStyleActionSheet];

UIAlertAction *actnCamera = [UIAlertAction actionWithTitle:@"Camera" style:UIAlertActionStyleDefault
                                                   handler:^(UIAlertAction * action) {
                                                   }];

UIAlertAction *actnLibrary = [UIAlertAction actionWithTitle:@"Library" style:UIAlertActionStyleDefault
                                                    handler:^(UIAlertAction * action) {
                                                    }];

[alertController addAction:actnLibrary];
[alertController addAction:actnCamera];
[alertController setModalPresentationStyle:UIModalPresentationPopover];
UIPopoverPresentationController *popPresenter = [alertController
                                                 popoverPresentationController];
popPresenter.sourceView = self.view;
CGRect frame = self.navigationController.navigationBar.frame;
frame.origin.x = self.navigationItem.leftBarButtonItem.width;
popPresenter.sourceRect = frame;
popPresenter.barButtonItem = self.navigationItem.leftBarButtonItem;
[self presentViewController:alertController animated:YES completion:nil];

输出