Improving ComboBoxColumn behavior to prevent triple click behavior

[bolyb]

Fixes #3161

This implementation fixes the need to click a ComboBox in a DataGridComboBoxColumn 3 times before the DropDown opens.

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

The current behavior is that in order to expand a ComboBox DropDown, the cell must first be clicked once to be highlighted, then the ComboBox must be clicked twice more before the DropDown expands.

For more information, see: https://github.com/CommunityToolkit/WindowsCommunityToolkit/issues/3161

What is the new behavior?

The new behavior is that after the ComboBox is clicked once to be highlighted, the next click expands the DropDown.

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
• New major technical changes in the toolkit have or will be added to the Wiki e.g. build changes, source generators, testing infrastructure, sample creation changes, etc...
• 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)
• Contains NO breaking changes

Other information

[ghost]

Thanks bolyb 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 🙌

[XAML-Knight]

Hi @bolyb, it appears you're trying to merge this code in from the main/master branch of your forked repo.

Please be aware of the rules & stipulations of submitting code into the Toolkit repo:

[bolyb]

Thank you for pointing me in the right direction on the correct procedures for this repo, I will close this pull request and create a new one from an appropriately named feature branch of my forked repo.