ComboBox: [MacCatalyst] InvalidOperationException when trying to open the dropdown in ListView or CollectionView

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Completed

Last Updated: 21 Dec 2023 13:19 by ADMIN

Release 6.6.0

Gabriel

Created on: 20 Nov 2023 08:33

Category: ComboBox

Type: Bug Report

ComboBox: [MacCatalyst] InvalidOperationException when trying to open the dropdown in ListView or CollectionView

If a RadComboBox is used as an ItemTemplate for a ListView or CollectionView on MacCatalyst, the application crashes every time you attempt to open the dropdown with the following exception:

System.InvalidOperationException: Event registration is overwriting existing delegate. Either just use events or your own delegate: Microsoft.Maui.Controls.Handlers.Items.ReorderableItemsViewDelegator`2[Microsoft.Maui.Controls.ReorderableItemsView,Microsoft.Maui.Controls.Handlers.Items.ReorderableItemsViewController`1[Microsoft.Maui.Controls.ReorderableItemsView]] UIKit.UIScrollView+_UIScrollViewDelegate
at UIKit.UIApplication.EnsureEventAndDelegateAreNotMismatched(Object del, Type expectedType)
at UIKit.UIScrollView.EnsureUIScrollViewDelegate()
at UIKit.UIScrollView.add_Scrolled(EventHandler value)
at Telerik.Maui.Controls.RadPopup.SetPopupIsOpen(Boolean value)
at Telerik.Maui.Controls.RadPopup.UpdatePopup()
..................

1 comment

ADMIN

Didi

Posted on: 20 Nov 2023 08:43

Workaround:

Inside the AppDelegate.cs file set the CheckForEventAndDelegateMismatches to false:

using Foundation;
using UIKit;
namespace TelerikComboboxBug;

[Register("AppDelegate")]
public class AppDelegate : MauiUIApplicationDelegate
{
    protected override MauiApp CreateMauiApp() {
        UIApplication.CheckForEventAndDelegateMismatches = false;
        return MauiProgram.CreateMauiApp();
    }
}

Regards,
Didi
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