[UWP] Fix Transparent Default Button (#468)

diff --git a/Xamarin.Forms.Platform.WinRT/FormsButton.cs b/Xamarin.Forms.Platform.WinRT/FormsButton.cs
index ffe75d4..b765948 100644 (file)
--- a/Xamarin.Forms.Platform.WinRT/FormsButton.cs
+++ b/Xamarin.Forms.Platform.WinRT/FormsButton.cs
@@ -74,7 +74,9 @@ namespace Xamarin.Forms.Platform.WinRT
 
                void UpdateBackgroundColor()
                {
-                       Background = Color.Transparent.ToBrush();
+                       if (BackgroundColor == null)
+                               BackgroundColor = Background;
+
 #if WINDOWS_UWP
                        if (_contentPresenter != null)
                                _contentPresenter.Background = BackgroundColor;
@@ -82,6 +84,7 @@ namespace Xamarin.Forms.Platform.WinRT
                        if (_border != null)
                                _border.Background = BackgroundColor;
 #endif
+                       Background = Color.Transparent.ToBrush();
                }
 
                void UpdateBorderRadius()