[iOS] Fixed the crash occurred on CarouselView2 when deleting last one remaining item with loop as false by Ahamed-Ali · Pull Request #31537 · dotnet/maui

Ahamed-Ali · 2025-09-09T10:08:14Z

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Root Cause of the issue

When removing the last item in CarouselView2 with Loop = false, the item count is updated with an additional +2. This logic is specific to the looping scenario (to handle duplicate items), but there was no handling for the non-looping case. As a result, the update produced invalid indices and caused the exception.

Description of Change

Added proper handling for the non-looping case (Loop = false) to prevent exceptions when removing the last item in CarouselView2.

Reference

https://github.com/dotnet/maui/blob/main/src/Controls/src/Core/Handlers/Items/iOS/LoopObservableItemsSource.cs#L25

Issues Fixed

Fixes #31535

Regression PR's

Tested the behaviour in the following platforms

Android
Windows
iOS
Mac

Screenshot

Before Issue Fix	After Issue Fix
Cv2crashloopfalse.mov	Cv2crashfixed.mov

…ning item with loop as false

Copilot

Pull Request Overview

This PR fixes a crash in CarouselView2 on iOS when removing the last remaining item with Loop set to false. The crash occurred because the existing logic was incorrectly adding +2 to the item count for all scenarios, but this additional count is only needed for looping carousels.

Key Changes:

Added proper handling for non-looping CarouselView2 scenarios to prevent invalid index calculations
Added comprehensive test coverage with both HostApp UI test page and NUnit test implementation

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
`src/Controls/src/Core/Handlers/Items2/iOS/LoopObservableItemsSource2.cs`	Added conditional check to use base implementation when Loop is false
`src/Controls/tests/TestCases.HostApp/Issues/Issue31535.cs`	Created UI test page demonstrating the crash scenario with CarouselView2
`src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31535.cs`	Added NUnit test to verify the fix prevents crashes when removing items

Copilot · 2025-09-09T11:20:31Z

src/Controls/tests/TestCases.HostApp/Issues/Issue31535.cs

+
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 31535, "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false", PlatformAffected.iOS)]


There's a spelling error in the issue description: 'occured' should be 'occurred'.

Suggested change

[Issue(IssueTracker.Github, 31535, "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false", PlatformAffected.iOS)]

[Issue(IssueTracker.Github, 31535, "[iOS] Crash occurred on CarouselView2 when deleting last one remaining item with loop as false", PlatformAffected.iOS)]

Copilot · 2025-09-09T11:20:32Z

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31535.cs

+{
+    public Issue31535(TestDevice device) : base(device) { }
+
+    public override string Issue => "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false";


There's a spelling error in the issue description: 'occured' should be 'occurred'.

Suggested change

public override string Issue => "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false";

public override string Issue => "[iOS] Crash occurred on CarouselView2 when deleting last one remaining item with loop as false";

jsuarezruiz · 2025-09-09T12:43:46Z

/azp run MAUI-UITests-public

azure-pipelines · 2025-09-09T12:43:57Z

Azure Pipelines successfully started running 1 pipeline(s).

src/Controls/src/Core/Handlers/Items2/iOS/LoopObservableItemsSource2.cs

jsuarezruiz · 2025-09-10T06:33:02Z

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31535.cs

+
+    [Test]
+    [Category(UITestCategories.CarouselView)]
+    public void CarouselView2ShouldNotCrashOnRemoveLastItem()


Could include another test, similar but removing more than one time the last item?

The current test already performs the remove action twice, so it seems you might be referring to the same scenario. Could you please confirm if this is sufficient, or would you prefer that we add more items and invoke the remove function multiple times? @jsuarezruiz

Something like:

Start with empty collection

Add single item - should not crash

Add multiple items - should work correctly

Remove all items - should handle gracefully

PureWeen · 2025-09-16T08:44:58Z

/azp run

azure-pipelines · 2025-09-16T08:45:22Z

Azure Pipelines successfully started running 3 pipeline(s).

jsuarezruiz · 2025-09-18T08:25:25Z

src/Controls/tests/TestCases.HostApp/Issues/Issue31535.cs

+        };
+
+        // Create Button
+        var button = new Button


Can include other button to add items?

Added the test covering scenarios.

Started with Empty colleciton
2.Added Single Item
3.Removed single item
4.Added Multiple Items
5.Removed All Items

@jsuarezruiz

jsuarezruiz · 2025-09-18T08:26:02Z

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31535.cs

+
+    [Test]
+    [Category(UITestCategories.CarouselView)]
+    public void CarouselView2ShouldNotCrashOnRemoveLastItem()


Something like:

Start with empty collection

Add single item - should not crash

Add multiple items - should work correctly

Remove all items - should handle gracefully

PureWeen · 2025-09-19T21:22:24Z

/azp run

azure-pipelines · 2025-09-19T21:22:54Z

Azure Pipelines successfully started running 3 pipeline(s).

Fixed the crash occured on CarouselView2 when deleting last one remai…

fece6b5

…ning item with loop as false

dotnet-policy-service bot added community ✨ Community Contribution partner/syncfusion Issues / PR's with Syncfusion collaboration labels Sep 9, 2025

Ahamed-Ali marked this pull request as ready for review September 9, 2025 11:19

Copilot AI review requested due to automatic review settings September 9, 2025 11:19

Ahamed-Ali requested a review from a team as a code owner September 9, 2025 11:19

sheiksyedm added platform/ios area-controls-collectionview CollectionView, CarouselView, IndicatorView collectionview-cv2 labels Sep 9, 2025

Copilot AI reviewed Sep 9, 2025

View reviewed changes

spell mistake

1e86b75

Ahamed-Ali changed the title ~~[iOS] Fixed the crash occured on CarouselView2 when deleting last one remaining item with loop as false~~ [iOS] Fixed the crash occurred on CarouselView2 when deleting last one remaining item with loop as false Sep 9, 2025

jsuarezruiz suggested changes Sep 10, 2025

View reviewed changes

mattleibow added this to MAUI SDK Ongoing Sep 11, 2025

github-project-automation bot moved this to Todo in MAUI SDK Ongoing Sep 11, 2025

mattleibow added the p/0 Current heighest priority issues that we are targeting for a release. label Sep 11, 2025

mattleibow moved this from Todo to Ready To Review in MAUI SDK Ongoing Sep 11, 2025

mattleibow moved this from Ready To Review to In Progress in MAUI SDK Ongoing Sep 11, 2025

PureWeen added this to the .NET 9 SR12 milestone Sep 11, 2025

PureWeen moved this from In Progress to Ready To Review in MAUI SDK Ongoing Sep 11, 2025

Addressed the edge case

4b29bbc

jsuarezruiz suggested changes Sep 18, 2025

View reviewed changes

github-project-automation bot moved this from Ready To Review to Changes Requested in MAUI SDK Ongoing Sep 18, 2025

Changed the test covering more scenarios

0bfd720

jsuarezruiz approved these changes Sep 23, 2025

View reviewed changes

github-project-automation bot moved this from Changes Requested to Approved in MAUI SDK Ongoing Sep 23, 2025

PureWeen merged commit b321d0e into dotnet:main Sep 23, 2025
130 checks passed

github-project-automation bot moved this from Approved to Done in MAUI SDK Ongoing Sep 23, 2025

github-actions bot locked and limited conversation to collaborators Oct 24, 2025


		namespace Maui.Controls.Sample.Issues;

		[Issue(IssueTracker.Github, 31535, "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false", PlatformAffected.iOS)]

	public override string Issue => "[iOS] Crash occured on CarouselView2 when deleting last one remaining item with loop as false";
	public override string Issue => "[iOS] Crash occurred on CarouselView2 when deleting last one remaining item with loop as false";

Conversation

Ahamed-Ali commented Sep 9, 2025

Root Cause of the issue

Description of Change

Reference

Issues Fixed

Regression PR's

Tested the behaviour in the following platforms

Screenshot

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jsuarezruiz commented Sep 9, 2025

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PureWeen commented Sep 16, 2025

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PureWeen commented Sep 19, 2025

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