Upgrade from older GTK template

[jeromelaban]

from @HakanL in #15738:

@MartinZikmund Is there any documentation on how to upgrade from GTK to Desktop? I've tried to create a new application using the templates, but since my real application is like 2 years old, the differences are quite big (single project, etc) and it's hard to figure out a good starting point. Could I perhaps start with just changing GtkHost to SkiaHostBuilder?

[jeromelaban]

@HakanL Upgrading using the SkiaHostBuilder directly may not necessarily work properly on all platforms, because of the automatic redirection done in net8.0-desktop. That being said, migrating to the newer structure is mostly about removing code and/or configuration in csproj. See the upgrade doc.

[HakanL]

I tried 5.3.0-dev.1916 and that builds, but the issue with the dialog boxes is still there. Do I need to do something else to get the pre-release of the extensions? Exception:
System.InvalidOperationException: Trying to set position of the dialog before it is associated with a visual tree. Make sure to use InitializeWithWindow before calling ShowAsync.

[jeromelaban]

Latest pre-release is 5.4.0-dev.135, try with this one and see if it helps. Once 5.3 is published it will contain the changes you need.

[HakanL]

Hmm, I must be doing something wrong. I've changed global.json to 5.4.0-dev.135 and it builds. But the dialog is still not working, however when I check what packages are dependent then I'm still getting extensions version 4.0.0, see image:

[jeromelaban]

This like means that you have an explicit version defined in your Directory.Build.props. You can remove all the version lines specified there. An update to the documentation is pending for this.

[HakanL]

Yes, you're absolutely correct, in fact I even had some in my Directory.Packages.props that I put in there as an attempt to get single-project to work with 5.1, forgot to remove them. Now I'm getting the latest and dialogs are working again. Thanks for all your help, sorry about all the questions, it's tricky to know how to interpret the errors and understand where it's coming from in MSBuild land.

[jeromelaban]

No worries and thanks for the troubleshooting, that's why we're simplifying our solutions to avoid all theses errors.

[HakanL]

Hmm, no, I definitely have the sdk reference in the csproj, it works if I just change the global.json to 5.2, no other change. But I can test some more with it in a sample project, just thought if you had any suggestions on what may trigger the issue. It seems to be during the restore stage (dotnet restore gives me the same error as VS).

[HakanL]

Aha, I didn’t realize they were two separate features in different releases, then it makes sense. I think the issue with dialogs is that it’s not back ported to 5.2 yet, or at least I don’t know which pre-version it would be in.