fix: fix numeric focus issue.

demo/Sandbox/Views/MainWindow.axaml

@@ -17,29 +17,17 @@
     </Design.DataContext>
 
     <Grid>
-        <DataGrid ItemsSource="{Binding Items}" IsReadOnly="False" HorizontalAlignment="Left">
+        <u:Form>
-            <DataGrid.Columns>
+            <u:FormItem Label="_Numeric">
-                <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
+                <u:NumericIntUpDown/>
-                
+            </u:FormItem>
-                <DataGridTemplateColumn Width="2*" Header="Address" MaxWidth="300" MinWidth="300">
+            <u:FormItem Label="_AnotherNumeric">
-                    <DataGridTemplateColumn.CellTemplate>
+                <u:NumericIntUpDown/>
-                        <DataTemplate>
+            </u:FormItem>
-                            <TextBlock
+            <u:FormItem Label="_TextBox">
-                                HorizontalAlignment="Center"
+                <TextBox/>
-                                VerticalAlignment="Center"
+            </u:FormItem>
-                                Text="{Binding Address}" />
+        </u:Form>
-                        </DataTemplate>
-                    </DataGridTemplateColumn.CellTemplate>
-                    <DataGridTemplateColumn.CellEditingTemplate>
-                        <DataTemplate>
-                            <u:IPv4Box
-                                HorizontalAlignment="Stretch"
-                                IPAddress="{Binding Address}" />
-                        </DataTemplate>
-                    </DataGridTemplateColumn.CellEditingTemplate>
-                </DataGridTemplateColumn>
-            </DataGrid.Columns>
-        </DataGrid>
     </Grid>
 
 </Window>

src/Ursa/Controls/NumericUpDown/NumericUpDownBase.cs

@@ -26,6 +26,7 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl, IInnerCon
     protected ButtonSpinner? _spinner;
     protected TextBox? _textBox;
     protected internal Panel? _dragPanel;
+    private bool _isFocused;
 
     private Point? _point;
     protected internal bool _updateFromTextInput;
@@ -149,6 +150,7 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl, IInnerCon
 
     static NumericUpDown()
     {
+        FocusableProperty.OverrideDefaultValue<NumericUpDown>(true);
         NumberFormatProperty.Changed.AddClassHandler<NumericUpDown>((o, e) => o.OnFormatChange(e));
         FormatStringProperty.Changed.AddClassHandler<NumericUpDown>((o, e) => o.OnFormatChange(e));
         IsReadOnlyProperty.Changed.AddClassHandler<NumericUpDown, bool>((o, args) => o.OnIsReadOnlyChanged(args));
@@ -216,6 +218,35 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl, IInnerCon
         {
             _dragPanel.IsVisible = true;
         }
+        FocusChanged(IsKeyboardFocusWithin);
+    }
+
+    protected override void OnGotFocus(GotFocusEventArgs e)
+    {
+        base.OnGotFocus(e);
+        FocusChanged(IsKeyboardFocusWithin);
+    }
+
+    private void FocusChanged(bool hasFocus)
+    {
+        // The OnGotFocus & OnLostFocus are asynchronously and cannot
+        // reliably tell you that have the focus.  All they do is let you
+        // know that the focus changed sometime in the past.  To determine
+        // if you currently have the focus you need to do consult the
+        // FocusManager.
+
+        bool wasFocused = _isFocused;
+        _isFocused = hasFocus;
+
+        if (hasFocus)
+        {
+
+            if (!wasFocused && _textBox != null)
+            {
+                _textBox.Focus();
+                _textBox.SelectAll();
+            }
+        }
     }
 
     protected override void OnKeyDown(KeyEventArgs e)