Fix for exception thrown when disconnecting page handlers in the Unloaded event while navigating on MacCatalyst and iOS#29410
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PureWeen merged 8 commits intodotnet:inflight/currentfrom Sep 10, 2025
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| @@ -0,0 +1,27 @@ | |||
| #if !ANDROID | |||
| //Skipping the test case to run in android because the loaded event is not triggered when navigating back to previous page. | |||
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Could you create a new bug and include the link to it here?
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I have logged new bug report for this issue.
#29414
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/azp run MAUI-UITests-public |
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| _loadedUnloadedToken?.Dispose(); | ||
| _loadedUnloadedToken = null; | ||
| _loadedUnloadedToken = this.OnLoaded(SendLoaded); | ||
| if (Handler is not null) |
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Can you also add the check for window?
Window?.Handler?.PlatformView
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Can you also add the check for window?
Window?.Handler?.PlatformView
The user is disconnecting the page handler during the Unloaded event. If we use the code Windows?.Handler?.PlatformView the exception will still occurs. Therefore, we need to ensure that the page's handler is not null before proceeding.
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/azp run MAUI-UITests-public |
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Azure Pipelines successfully started running 1 pipeline(s). |
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/azp run MAUI-UITests-public |
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Azure Pipelines successfully started running 1 pipeline(s). |
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/rebase |
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…aded event while navigating on MacCatalyst and iOS (#29410) * Fixed Crash on shell navigation for Mac Catalyst * Test case added * test case name modified * updated the fix * Issue linked * curly brace added * modified the condition. * Modified the fix
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Sep 18, 2025
…aded event while navigating on MacCatalyst and iOS (#29410) * Fixed Crash on shell navigation for Mac Catalyst * Test case added * test case name modified * updated the fix * Issue linked * curly brace added * modified the condition. * Modified the fix
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…aded event while navigating on MacCatalyst and iOS (#29410) * Fixed Crash on shell navigation for Mac Catalyst * Test case added * test case name modified * updated the fix * Issue linked * curly brace added * modified the condition. * Modified the fix
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…aded event while navigating on MacCatalyst and iOS (#29410) * Fixed Crash on shell navigation for Mac Catalyst * Test case added * test case name modified * updated the fix * Issue linked * curly brace added * modified the condition. * Modified the fix
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…aded event while navigating on MacCatalyst and iOS (#29410) * Fixed Crash on shell navigation for Mac Catalyst * Test case added * test case name modified * updated the fix * Issue linked * curly brace added * modified the condition. * Modified the fix
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Issue Details:
When navigating away from the current page, the user disconnects all handlers including those of visual elements and the page itself during the Unloaded event of the current page. This leads to crash with a message " System.InvalidOperationException" is thrown when navigating back to the previous page.
Root Cause:
When navigating back to the previous page, the Unloaded event of the current page is triggered. As part of this event, the handler for the page is explicitly disconnected by the user. However, after the handler is cleared and the Unloaded event is attempts to save a token for wiring up the Loaded event via the SendLoaded method.
At this point, since the handler has already been set to null, calling SendLoaded results in a System.InvalidOperationException, as it requires a valid handler. This is why the exception only occurs during backward navigation.
Description of Change:
I have applied condition to call the SendLoaded method only if the handler is not null in iOS and Mac platform.
Tested the behavior in the following platforms.
Reference:
N/A
Issues Fixed:
Fixes #29297
Screenshots
withoutfix.mov
withfix.mov