helpfocusing on Dialog UpdateContent. fixes #445

Author: ButchersBoy

MaterialDesignThemes.Wpf/DialogHost.cs

@@ -288,8 +288,8 @@ private static void IsOpenPropertyChangedCallback(DependencyObject dependencyObj
 
             dialogHost.Dispatcher.BeginInvoke(DispatcherPriority.Background, new Action(() =>
             {
-                var child = dialogHost.FocusPopup();
                 CommandManager.InvalidateRequerySuggested();
+                var child = dialogHost.FocusPopup();
 
                 //https://github.com/ButchersBoy/MaterialDesignInXamlToolkit/issues/187
                 //totally not happy about this, but on immediate validation we can get some weird looking stuff...give WPF a kick to refresh...
@@ -575,8 +575,14 @@ internal UIElement FocusPopup()
             var child = _popup?.Child;
             if (child == null) return null;
 
-            child.Focus();
-            child.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
+            CommandManager.InvalidateRequerySuggested();
+            var focusable = child.VisualDepthFirstTraversal().OfType<UIElement>().FirstOrDefault(ui => ui.Focusable && ui.IsVisible);
+            focusable?.Dispatcher.InvokeAsync(() =>
+            {
+                if (!focusable.Focus()) return;
+                focusable.MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
+            }, DispatcherPriority.Background);
+
             return child;
         }
 

MaterialDesignThemes.Wpf/DialogSession.cs

@@ -42,9 +42,8 @@ public void UpdateContent(object content)
             _owner.AssertTargetableContent();
             _owner.DialogContent = content;
             _owner.Dispatcher.BeginInvoke(DispatcherPriority.Background, new Action(() =>
-            {
-                _owner.FocusPopup();
-                CommandManager.InvalidateRequerySuggested();
+            {                
+                _owner.FocusPopup();                
             }));            
         }
 

MaterialDesignThemes.Wpf/Extensions.cs

@@ -24,6 +24,27 @@ public static IEnumerable<DependencyObject> VisualDepthFirstTraversal(this Depen
             }
         }
 
+        public static IEnumerable<DependencyObject> VisualBreadthFirstTraversal(this DependencyObject node)
+        {
+            if (node == null) throw new ArgumentNullException(nameof(node));            
+
+            for (var i = 0; i < VisualTreeHelper.GetChildrenCount(node); i++)
+            {
+                var child = VisualTreeHelper.GetChild(node, i);
+                yield return child;                
+            }
+
+            for (var i = 0; i < VisualTreeHelper.GetChildrenCount(node); i++)
+            {
+                var child = VisualTreeHelper.GetChild(node, i);
+                
+                foreach (var descendant in child.VisualDepthFirstTraversal())
+                {
+                    yield return descendant;
+                }
+            }
+        }
+
         public static bool IsAncestorOf(this DependencyObject parent, DependencyObject node)
         {
             return node != null && parent.VisualDepthFirstTraversal().Contains(node);

MaterialDesignThemes.Wpf/Themes/Generic.xaml

@@ -617,6 +617,7 @@
                                         TextElement.FontSize="13"
                                         TextOptions.TextFormattingMode="Ideal"
                                         TextOptions.TextRenderingMode="Auto"
+                                        FocusManager.IsFocusScope="True"
                                         Foreground="{DynamicResource MaterialDesignBody}"
                                         FontFamily="{StaticResource MaterialDesignFont}"
                                         Focusable="False"