Xamarin.iOS UIPopoverPresentationController Exception

Question

I am having difficulty presenting a Popover with UIPopoverPresentationController, following what can I find from the internet, including this and this. Nothing has helped. Here's a test app I created:

ViewController.cs

  public override void ViewDidLoad()
  {
     ...

     var popupView = new UIImageView(new CGRect(0, 0, 200, 200))
     {
        Image = UIImage.FromBundle("Menu")
     };

     _menuController = new UIViewController
     {
        ModalPresentationStyle = UIModalPresentationStyle.Popover,
        View = popupView
     };

     _presentationController = new UIPopoverPresentationController(_menuController, this)
     {
        SourceView = View,
        SourceRect = new CGRect(50, 50, 300, 300),
     };
  }

And I invoke on button press with:

  PresentViewController(_menuController, true, null);

I get this exception when the presentation style is Popover:

UIPopoverPresentationController should have a non-nil sourceView or barButtonItem set before the presentation occurs.

score 1 · Accepted Answer · answered Apr 20 '18 at 02:02

Every UIViewController has a UIPopoverPresentationController called PopoverPresentationController, you can just use that to present your pop view:

private void OnMenuSelected(object sender, EventArgs eventArgs)
{
    var popupView = new UIImageView(new CGRect(0, 0, 200, 200))
    {
        Image = UIImage.FromBundle("Menu"),
        UserInteractionEnabled = true
    };

    _menuController = new UIViewController
    {
        ModalPresentationStyle = UIModalPresentationStyle.Popover,
        PreferredContentSize = new CGSize(200, 200),
        View = popupView
    };

    _menuController.PopoverPresentationController.SourceRect = new CGRect(50, 50, 300, 300);
    _menuController.PopoverPresentationController.SourceView = View;


    PresentViewController(_menuController, true, null);
}

I find that when we dismiss the popoverview, it will return to null. So here I recommend you to initialize it in your method every time when you show it up.

Moreover if you want to achieve the same effect on iPhone, please add the UIPopoverPresentationControllerDelegate like:

public override UIModalPresentationStyle GetAdaptivePresentationStyle(UIPresentationController forPresentationController)
{
    return UIModalPresentationStyle.None;
}

Set the delegate to it: _menuController.PopoverPresentationController.Delegate = new MyPopOverViewDelegate();

The key here is initializing `UIViewController.PopoverPresentationController` instead of creating a new instance. Thanks — Joseph, Apr 20 '18 at 18:29
And creating the View on each "click" prevents the exception when showing the popover more than once. Thanks again — Joseph, Apr 20 '18 at 18:31

score 0 · Answer 2 · answered Apr 19 '18 at 22:13

0

You need to set the UIPopoverPresentationController.SourceView to a UIView that is outside the view controller to provide a view that becomes the anchor point, i.e. a UIView on the parent view controller

You say present this via a button touch, you could use that button as the source (if that location is appropriate).

_presentationController = new UIPopoverPresentationController(_menuController, this)
{
    SourceView = button,
    SourceRect = new CGRect(50, 50, 300, 300),
};

Example:

answered Apr 19 '18 at 22:13

SushiHangover

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Hey thanks for your response. I must be misunderstanding something -- the `View` in my code is the top-level view, other than the app `Window` presumably. My `button` didn't work, as it's added and contained in `View`. – Joseph Apr 19 '18 at 22:23
Are you referring to `this.ParentViewController`? Here it's null. – Joseph Apr 19 '18 at 22:25

Xamarin.iOS UIPopoverPresentationController Exception

2 Answers2

Example:

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