Currently, we offer a LineDecoration Behavior that can be applied to TextBlocks.

However, within Studio, when a LineDecoration Behavior is applied to a TextBlock, and configured, it fails to display the results on-Stage without closing and re-opening the Page

Similarly, when a the LineDecoration Behavior is removed from a TextBlock, it fails to remove it from the Stage's preview, until the Page is closed and re-opened.

See attached video.

Repro Steps:

1) Create a Studio Project featuring a MainPage.xaml

2) Introduce a nice and large TextBlock to the Page.

3) Navigate to the Interactivity/Behaviors Panel, select the TextBlock, and attach a LineDecoration Behavior to it.

4) Select the new LineDecoration Behavior to display its Properties in the Properties Panel, and set its Properties to: Offset: 32 | Pen: Pen | Pen Thickness: 64 | Pen Brush: Red
Observe how the LineDecoration configured is not visible on-Stage.

5) Play the Page.
Observe how the LineDecoration Behavior is now visible on the TextBlock.

6) Save MainPage.xaml, then close and re-open it.
Observe how the LineDecoration Behavior is now visible.

7) Select the LineDecoration Behavior again, and adjust its 'Pen Thickness' Property.
Observe how the changes-in-progress are visible on-Stage.

7) From the Behaviors Panel, delete the LineDecoration Behavior from the TextBlock.
Observe how the visuals of the LineDecoration Behavior persist on-Stage.

8) Save MainPage.xaml, then close and re-open it.
Observe how now the LineDecoration Behavior has been successfully visually removed from the TextBlock.

Expected Results: Adding a LineDecoration Behavior renders its results immediately on the Stage in Editor Mode.
Expected Results; Deleting a LineDecoration Behavior visually removes it immediately on the Stage in Editor Mode.