IPAD 从 UIAlertController 样式呈现 UIActivityViewController UIAlertControllerActionSheet“无法同时满足约束”

问：

我将 UIAlertController 作为操作表呈现，其中包含一个按钮，该按钮在选中时应打开 ActivityView。

这两种方法都在同一个 ViewController 类中...并且可以在 iphone 8、iPhone Pro 11 Max 等上运行良好。但在 iPad 上测试时失败。（全部运行 13.5）

最初的失败是 popoverPresentationController 没有设置 sourceview 或 barbuttonitem（或类似的东西），所以我添加了以下行：

activityViewController.popoverPresentationController.sourceView = [self view];

到 share 方法。这让我度过了难关......因此，现在 IPAD 不会因 GenericException 而崩溃。但它也从不显示 activityView。它只是抛出一堆约束冲突，这些冲突似乎与尝试显示的 ActivityView 有关，

[LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. 
Try this: 
    (1) look at each constraint and try to figure out which you don't expect; 
    (2) find the code that added the unwanted constraint or constraints and fix it. 
(
"<NSLayoutConstraint:0x6000000d2580 LPLinkView:0x7fda08498900.leading == UILayoutGuide:0x600001a39dc0'UIViewLayoutMarginsGuide'.leading   (active)>",
"<NSLayoutConstraint:0x6000000d23f0 H:[LPLinkView:0x7fda08498900]-(59)-|   (active, names: '|':_UIActivityContentTitleView:0x7fda08493b90 )>",
"<NSLayoutConstraint:0x6000000cf660 H:|-(0)-[_UIActivityContentTitleView:0x7fda08493b90]   (active, names: '|':_UINavigationBarContentView:0x7fda085d5550 )>",
"<NSLayoutConstraint:0x6000000cf6b0 _UIActivityContentTitleView:0x7fda08493b90.trailing == _UINavigationBarContentView:0x7fda085d5550.trailing   (active)>",
"<NSLayoutConstraint:0x6000000d08c0 'UIView-Encapsulated-Layout-Width' _UINavigationBarContentView:0x7fda085d5550.width == 0   (active)>",
"<NSLayoutConstraint:0x6000000d2260 'UIView-leftMargin-guide-constraint' H:|-(16)-[UILayoutGuide:0x600001a39dc0'UIViewLayoutMarginsGuide'](LTR)   (active, names: '|':_UIActivityContentTitleView:0x7fda08493b90 )>"

)

但我对此没有任何限制..以及关于引用我的应用程序没有或使用的导航栏的投诉区域。这些限制必须来自某些默认设置，这些设置仅与 IPAD 相关。有谁知道我需要在这里做些什么才能在IPAD上解决这个问题？为什么默认约束与我从未设置过的东西有关..我只设置了sourceView。

-(UIAlertController *)displayActionSheet
{
UIAlertController *sheet = [UIAlertController
                            alertControllerWithTitle:nil
                            message:nil
                            preferredStyle:UIAlertControllerStyleActionSheet];
.
.
.

UIAlertAction *share = [UIAlertAction
                          actionWithTitle:NSLocalizedString(@"Share with Friends", @"Share with Friends")
                          style:UIAlertActionStyleDefault
                          handler:^(UIAlertAction *action){
                          [self share];
                          }];


[sheet addAction:share];
.
.
.

[sheet popoverPresentationController].sourceView = [self view];
sheet.popoverPresentationController.permittedArrowDirections = 0;
[sheet popoverPresentationController].sourceRect =  CGRectMake(view.bounds.size.width/2, view.bounds.size.height/2, 0, 0);
[self presentViewController:sheet animated:YES completion:nil];
return sheet;
}




-(void)share
{
  NSString *shareString = @"a string to share";
  UIImage *shareImage = [UIImage imageNamed:@"animagetoshare"];
  NSURL *shareUrl = [NSURL URLWithString:@"a url to share"];

 NSArray *activityItems = [NSArray arrayWithObjects:shareString, shareImage, shareUrl, nil];

 UIActivityViewController *activityViewController = [[[UIActivityViewController alloc] 
 initWithActivityItems:activityItems applicationActivities:nil] autorelease];
 activityViewController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
 activityViewController.excludedActivityTypes = @[UIActivityTypePrint, 
 UIActivityTypeCopyToPasteboard, UIActivityTypeAssignToContact, 
 UIActivityTypeSaveToCameraRoll, UIActivityTypeAddToReadingList];
 activityViewController.popoverPresentationController.sourceView = [self view];
 [self  presentViewController:activityViewController animated:YES completion:nil];
}