changed xaml code to code to avoid crash

Author: vgromfeld

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/FocusBehavior/FocusBehaviorXaml.bind

@@ -8,9 +8,9 @@
 
   <interactivity:Interaction.Behaviors>
     <behaviors:FocusBehavior>
-      <behaviors:FocusTarget Control="{Binding ElementName=disabledItem}" />
-      <behaviors:FocusTarget Control="{Binding ElementName=emptyList}" />
-      <behaviors:FocusTarget Control="{Binding ElementName=enabledItem}" />
+      <behaviors:FocusTarget Control="{x:Bind disabledItem}" />
+      <behaviors:FocusTarget Control="{x:Bind emptyList}" />
+      <behaviors:FocusTarget Control="{x:Bind enabledItem}" />
     </behaviors:FocusBehavior>
   </interactivity:Interaction.Behaviors>
 

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/samples.json

@@ -897,7 +897,7 @@
         "Subcategory": "Systems",
         "About": "Behavior to automatically set the focus on the first control which accepts it",
         "CodeUrl": "https://github.com/windows-toolkit/WindowsCommunityToolkit/tree/master/Microsoft.Toolkit.Uwp.UI/Behaviors/",
-        "XamlCodeFile": "FocusBehaviorXaml.bind",
+        "CodeFile": "FocusBehaviorXaml.bind",
         "Icon": "/Assets/Helpers.png",
         "DocumentationUrl": "https://raw.githubusercontent.com/MicrosoftDocs/WindowsCommunityToolkitDocs/master/docs/behaviors/FocusBehavior.md"
       },

Microsoft.Toolkit.Uwp.UI/Behaviors/FocusBehavior.cs

@@ -112,8 +112,6 @@ private void ApplyFocus()
             }
         }
 
-        private void OnControlPropertyChanged(DependencyObject sender, DependencyProperty dp) => ApplyFocus();
-
         private void OnEngagementTimerTick(object sender, object e)
         {
             ApplyFocus();