iOS AppDelegate - Override for PerformFetch is not available

Description

I’m currently migrating my Xamarin.Forms app to .NET MAUI. Now I stuck on the BackgroundFetch on iOS.

In Xamarin I was able to override the PerformFetch method

public override async void PerformFetch(UIApplication application, Action<UIBackgroundFetchResult> completionHandler)
{
    //Console.WriteLine("App is performing background fetch.");
    try
    {
        await service?.RefreshAsync(application, completionHandler);
    }
    catch(Exception exc)
    {
        EventManager.LogError(exc, forceReport: true);
    }
}

In the .NET MAUI AppDelegate, this method is not available for now.

I searched the docs, but the only thing I found was for Xamarin.Forms. https://docs.microsoft.com/en-us/dotnet/api/uikit.uiapplicationdelegate.performfetch?view=xamarin-ios-sdk-12

Steps to Reproduce

1. Try to override the PerformFetch method on iOS (AppDelegate)

Version with bug

6.0 (current)

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

Any

Did you find any workaround?

No response

Relevant log output

No response

[faceoffers28]

@g0dpain Can you try something like this? Notice the Export tag and the lack of override. I’m able to call PerformFetch from an iOS 6 15.4 app. Works on Asp.net 7 and iOS 16 as well.

Added this to FinishedLaunching.

UIApplication.SharedApplication.SetMinimumBackgroundFetchInterval(UIApplication.BackgroundFetchIntervalMinimum);

    [Export("application:performFetchWithCompletionHandler:")]
    public void PerformFetch(UIApplication application, Action<UIBackgroundFetchResult> completionHandler)
    {
        // Perform task

        // Inform system of fetch results
        completionHandler(UIBackgroundFetchResult.NewData);
    }

[AndreasReitberger]

@jfversluis any chance that the attached PR will be merged soon? Thank you!