Xamarin.Forms iOS: TabbedPage Children's INavigationAware

[haythamnikolaidis]

Package info

• Platform: iOS 11.1
• Prism version: 6.3
• Xamarin version (if applicable): Xamarin.iOS: 11.3.0.47 Xamarin.Forms 2.5.0

Repro steps

Example Project to reproduce the behaviour: https://github.com/haythamnikolaidis/ImbeddedNavigationIssue-

When creating a TabbedPage in Xamarin.Forms on iOS that has more then 5 tabs the TabbedPage creates a "More" tab with a list view to select the tabs from 5 and up.

For tabs in this "More" list (and only in this list) the INavigationAware callbacks are not fired on back navigation (Navigation Bar back button or INavigationService.GoBackAsync()). However they are fired as expected in tabs that are not in the "More" list.

In the above example app, once its open on any of the first four tabs and tapping the NavigateToDetails button, upon navigating back, NavigatedTo is fired and the label is updated on screen.

However doing the same in the last three tabs, results in the NavigatedTo not being fired and the label not being updated on screen.

[brianlagunas]

Thanks for reporting this. It seems iOS handles overflow tabs differently than normal tabs. I'll have to look into the cause of this and see if there is a way to fix it.

[brianlagunas]

Turns out that the TabbedPage.CurrentPage is null on iOS when in the "More" group. I'm not sure this can be fixed as I don't see a way to access the current tab. Let me dig around and see what I can find. If you have any ideas on how to approach this, please feel free to throw out your ideas.

[brianlagunas]

I have reported this bug to Xamarin, and will update this issue when a fix has been provided:

xamarin/Xamarin.Forms#1336

[haythamnikolaidis]

@brianlagunas Thank you for the help, I will keep my eye on the Xamarin bug report.

[dansiegel]

Adding a Help Wanted for this issue. This is a Xamarin.Forms issue, however this issue is up for grabs for anyone in the community that would like to help fix the issue directly in Xamarin.Forms. Please see the xamarin/Xamarin.Forms#1336 issue

[brianlagunas]

After 4 years, we have come to the conclusion that Xamarin will never fix this. Closing because it pointless to have this open 😄

[haythamnikolaidis]

Thanks for hanging onto this for so long @brianlagunas 😂