I'm trying to implement a numeric-only Entry view using an attached Behaviour to reject invalid keypresses as they are entered. Unable to get it to work as expected, I downloaded your sample app and found that it shows exactly the same problem where changes made to the Entry view by the Behaviour are not reflected in the UI. The sample works fine under iOS, it's just UWP that seems to be the problem.
iOS screenshot : https://gyazo.com/511cba7c8b654eb8cac7463460b492ba
UWP screenshot : https://gyazo.com/12c2a598fc2c4edde89ad5461dd758a9
# Steps to reproduce
Downloaded the Xamarin Behaivours sample project ...
# Expected behavior
The Behavior should be able to affect the Entry view, in the case of the sample it should change the color to red if the entered text is not numeric.
# Actual behaviour
The Behaviour handler is not having any visible affect on the entered text.
# Test environment (full version information)
Windows 10, VS2015, Xamarin.Forms 22.214.171.124
Confirmed up through 126.96.36.199-pre3
The behavior fires when invalid text is entered and sets the TextColor to red, but the actual on-screen text doesn't change color until the Entry loses focus. I suspect this might just be an issue with invalidating the underlying TextBox control so that it redraws.
@E.Z.Hart - Is there any timescale for fixing this one? I've tried all the obvious workarounds, but all either don't work or result in a horrible user experience.
Should be fixed in the next release.
*** Bug 43676 has been marked as a duplicate of this bug. ***
I have checked this issue with Xamarin.Forms 188.8.131.52-pre1 and observed that this issue has been fixed.