Create a shared project with all Win App common files (8.1 and 10)

Finally use the dependency injected Resource Service

WinAppCommon/Actions/SetupFocusAction.cs

@@ -0,0 +1,27 @@
+using System.Threading.Tasks;
+using Windows.UI.Core;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Microsoft.Xaml.Interactivity;
+
+namespace ModernKeePass.Actions
+{
+    public class SetupFocusAction : DependencyObject, IAction
+    {
+        public Control TargetObject
+        {
+            get { return (Control)GetValue(TargetObjectProperty); }
+            set { SetValue(TargetObjectProperty, value); }
+        }
+
+        public static readonly DependencyProperty TargetObjectProperty =
+            DependencyProperty.Register("TargetObject", typeof(Control), typeof(SetupFocusAction), new PropertyMetadata(null));
+
+        public object Execute(object sender, object parameter)
+        {
+            return Task.Factory.StartNew(
+                () => Dispatcher.RunAsync(CoreDispatcherPriority.Low,
+                    () => TargetObject?.Focus(FocusState.Programmatic)));
+        }
+    }
+}