Add HorizontalContentAlignment/VerticalContentAlignment props to CalendarDatePicker

src/Avalonia.Controls/Calendar/CalendarDatePicker.cs

@@ -11,6 +11,7 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Avalonia.Layout;
 
 namespace Avalonia.Controls
 {
@@ -209,6 +210,18 @@ namespace Avalonia.Controls
             TextBox.UseFloatingWatermarkProperty.AddOwner<CalendarDatePicker>();
 
 
+        /// <summary>
+        /// Defines the <see cref="HorizontalContentAlignment"/> property.
+        /// </summary>
+        public static readonly StyledProperty<HorizontalAlignment> HorizontalContentAlignmentProperty =
+            ContentControl.HorizontalContentAlignmentProperty.AddOwner<CalendarDatePicker>();
+
+        /// <summary>
+        /// Defines the <see cref="VerticalContentAlignment"/> property.
+        /// </summary>
+        public static readonly StyledProperty<VerticalAlignment> VerticalContentAlignmentProperty =
+            ContentControl.VerticalContentAlignmentProperty.AddOwner<CalendarDatePicker>();
+
         /// <summary>
         /// Gets or sets the date to display.
         /// </summary>
@@ -364,6 +377,25 @@ namespace Avalonia.Controls
             set { SetValue(UseFloatingWatermarkProperty, value); }
         }
 
+
+        /// <summary>
+        /// Gets or sets the horizontal alignment of the content within the control.
+        /// </summary>
+        public HorizontalAlignment HorizontalContentAlignment
+        {
+            get => GetValue(HorizontalContentAlignmentProperty);
+            set => SetValue(HorizontalContentAlignmentProperty, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the vertical alignment of the content within the control.
+        /// </summary>
+        public VerticalAlignment VerticalContentAlignment
+        {
+            get => GetValue(VerticalContentAlignmentProperty);
+            set => SetValue(VerticalContentAlignmentProperty, value);
+        }
+
         /// <summary>
         /// Occurs when the drop-down
         /// <see cref="T:Avalonia.Controls.Calendar" /> is closed.

src/Avalonia.Themes.Default/CalendarDatePicker.xaml

@@ -93,6 +93,8 @@
                    Watermark="{TemplateBinding Watermark}"
                    UseFloatingWatermark="{TemplateBinding UseFloatingWatermark}"
                    DataValidationErrors.Errors="{TemplateBinding (DataValidationErrors.Errors)}"
+                   VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
+                   HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                    Grid.Column="0"/>
 
           <Button Name="PART_Button"

src/Avalonia.Themes.Fluent/Controls/CalendarDatePicker.xaml

@@ -9,8 +9,10 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:sys="clr-namespace:System;assembly=netstandard">
   <Design.PreviewWith>
-    <Border Margin="20">
-      <CalendarDatePicker/>
+    <Border Margin="20, 20, 20, 200">
+      <CalendarDatePicker Width="200"
+                          VerticalContentAlignment="Center"
+                          HorizontalContentAlignment="Center" />
     </Border>
   </Design.PreviewWith>
 
@@ -104,6 +106,8 @@
                    Watermark="{TemplateBinding Watermark}"
                    UseFloatingWatermark="{TemplateBinding UseFloatingWatermark}"
                    DataValidationErrors.Errors="{TemplateBinding (DataValidationErrors.Errors)}"
+                   VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
+                   HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                    Grid.Column="0"/>
 
           <Button Name="PART_Button"