ImageEx CornerRadius RS3 Support and RoundImageEx Obsolete Notice

[michael-hawker]

Issue: #1391

PR Type

What kind of change does this PR introduce?

[ x ] Bugfix
[ x ] Feature
[ ] Code style update (formatting)
[ x ] Refactoring (no functional changes, no api changes)
[ ] Build or CI related changes
[ x ] Documentation content changes
[ ] Sample app changes
[ x ] Other... Please describe:  Deprecation

What is the current behavior?

Round Image uses its own custom brush and behaves differently than Image/ImageEx in layout (Issue #1391)

PR Checklist

Please check if your PR fulfills the following requirements:

• [ x ] Tested code with current supported SDKs
• [ x ] Docs have been added / updated (for bug fixes / features)
• [ x ] Sample in sample app has been added / updated (for bug fixes / features)
• [ x ] Tests for the changes have been added (for bug fixes / features) (if applicable)

What is the new behavior?

This adds a CornerRadius property to ImageEx to replace the need for RoundImageEx entirely, now that RS3 properly supports the CornerRadius property.

Does this PR introduce a breaking change?

[ ] Yes
[ x ] No*

Does mark RoundImageEx as Obsolete.

Other information

If trying to use new CornerRadius on ImageEx on down-level platforms, rendering is not as expected, as if had tried to do the same on a Grid surrounding an Image.

[nmetulev]

Looks great, only have a small request to change the wording in the sample from RS3 to Fall Creators Update

[nmetulev]

Can you change this from RS3 to Fall Creators Update?

[michael-hawker]

@nmetulev updated wording, so we should be all set now.

[WilliamABradley]

@nmetulev So you won't actually remove the Code for RoundImageEx, until Fall Creators Update becomes Minimum Supported Version of the UWP Community Toolkit? It just has the Obsolete flag?

[nmetulev]

Yeah, we won't remove it until a future major update

[WilliamABradley]

Future Major update of the Toolkit, or Windows? Having RoundImageEx is helpful for Backwards Compat.

[nmetulev]

Agree with you. Need to make sure we don't create any breaking changes and continue support our min version. Breaking changes only happen on major releases of the toolkit.