Description

• AppTitleBarTextBox 's Width is not set, so Width +=1 does nothing
• The SizeChanged event handler is called once, because of Visibility changed, and it was put in a StackPanel that's vertically constrained, so the size change will occur once, not because Width += 1. Consecutive adding it to the title bar no longer triggers the event handler, therefore the issue
• And Width += 1 is a dirty hack anyway, does not need that.

Motivation and Context

Close #1470

How Has This Been Tested?

Manual.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)