.NET Core 3.0 support for desktop toasts

[andrewleader]

Fixes #3212

The DesktopNotificationManagerCompat library didn't work with .NET Core 3.0 apps due to the lack of some APIs, figured out a workaround thanks to the community help of FrecherxDachs.

PR Type

What kind of change does this PR introduce?

Bugfix

What is the current behavior?

Toast library didn't work for .NET Core 3.0 WPF apps

What is the new behavior?

Toast library now works for .NET Core 3.0 WPF apps

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Pull Request has been submitted to the documentation repository instructions. Link:
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• If new feature, add to Feature List
• Contains NO breaking changes

Other information

[ghost]

Thanks andrewleader for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌

[michael-hawker]

Thanks @andrewleader, I've got a thread open with our legal advisors about making sure we've done the credit right, so just adding the do not merge tag until I can circle back.

In the meantime, I think @sibille you've already validated this solution should work?

[andrewleader]

👍 I've also got to validate with the NuGet packages from the build server, I'll post when I've validated everything

[Felix-Dev]

Tested this solution and happy to report that it works.

Tested with a .NET Core 3.1 MSIX packaged desktop app with toast input (selection menu). App activation and app launching both worked.

Good job @andrewleader @FrecherxDachs 👍

[andrewleader]

NuGet packages don't seem to work, the DesktopNotificationManager code probably isn't getting included in the NuGet package, none of the classes from that class are appearing. So I'm still investigating that.

[MichaeIDietrich]

Nice to see the code makes it into the toolkit. 👍🏻

[michael-hawker]

Have Legal feedback, minor things, let me know your thoughts too from how you've done this in the past.

[ghost]

This PR has been marked as "needs attention 👋" and awaiting a response from the team.

[michael-hawker]

@andrewleader thanks for the updates, but couple of StyleCop nitpicks stopping the CI build:

DesktopNotificationManager\DesktopNotificationManagerCompat.cs(80,1): error SA1507: Code should not contain multiple blank lines in a row [D:\a\1\s\Microsoft.Toolkit.Uwp.Notifications\Microsoft.Toolkit.Uwp.Notifications.csproj]
DesktopNotificationManager\DesktopNotificationManagerCompat.cs(81,1): error SA1028: Code should not contain trailing whitespace [D:\a\1\s\Microsoft.Toolkit.Uwp.Notifications\Microsoft.Toolkit.Uwp.Notifications.csproj]

[michael-hawker]

@sibille I know you've tested the sample code earlier, but would you have a chance to validate these bits as integrated into the toolkit against your scenario?

[sibille]

@mvegaca just tested it, looks good to us!