Fix the scrollbar attaching to wrong scrollviewer, like scrollviewer …

[liwuqingxin]

…outer a datagrid.

What does the pull request do?

Fix the bug that the scrollbar could attach to a wrong scrollviewer, like a scrollviewer outer a datagrid. #12482

What is the current behavior?

The scrollbar in control template of datagrid will find a nearest ancestor scrollviewer and attach to it. And there is no scrollviewer in control template of datagrid, the scrollbar in it's template will attach to the scrollviewer outer the datagrid, if it exsits.

Then, if we scroll the datagrid, the outer scrollviewer will be scrolled too.

What is the updated/expected behavior with this PR?

The scrollbar will not find the ancestor scrollviewer to attach to now. Instead it will try to attach to it's templatedparent if it is a scrollviewer.

I don't find any case that the scrollbar should bind to a scrollviewer that is not the scrollbar's tempatedparent. So if the case exists, stop this PR please.

How was the solution implemented (if it's not obvious)?

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/Documentation with user documentation

Breaking changes

None.

Obsoletions / Deprecations

Fixed issues

Fixes #12482

[liwuqingxin]

@dotnet-policy-service agree

[avaloniaui-team]

You can test this PR using the following package version. 11.0.999-cibuild0038980-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[maxkatz6]

Can't imagine any scenario, when ScrollViewer is not a TemplatedParent for ScrollBar.
So, LGTM.

[liwuqingxin]

@maxkatz6 I don't know why the AvaloniaUI.IntegrationTests(Mac) failed with the error like:

OpenQA.Selenium.WebDriverException : An unknown server-side error occurred while processing the command. Original error: 'POST /element' cannot be proxied to Mac2 Driver server because its process is not running (probably crashed). Check the Appium log for more details

Could you please tell me what should I do? 😅

[timunie]

@liwuqingxin sometimes the tests are running too long and break, esp. if there are several builds running. So I try to re-run them.

[avaloniaui-team]

You can test this PR using the following package version. 11.0.999-cibuild0038996-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]