feat: remove header from DatePicker.

samples/ControlCatalog/Pages/DateTimePickerPage.xaml

@@ -13,17 +13,17 @@
                 Margin="16"
                 HorizontalAlignment="Stretch"
                 Spacing="16">
-      <TextBlock FontSize="18">A simple DatePicker with a header</TextBlock>
+      <TextBlock FontSize="18">A simple DatePicker</TextBlock>
       <StackPanel Orientation="Vertical">
         <Border BorderBrush="{DynamicResource SystemControlHighlightBaseLowBrush}"
                 BorderThickness="1" Padding="15">
-          <DatePicker Header="Pick a date" />
+          <DatePicker />
         </Border>
         <Panel Background="{DynamicResource SystemControlBackgroundBaseLowBrush}">
           <TextBlock Padding="15">
             <TextBlock.Text>
               <x:String>
-                &lt;DatePicker Header="Pick a date" /&gt;
+                &lt;DatePicker/&gt;
               </x:String>
             </TextBlock.Text>
           </TextBlock>
@@ -33,7 +33,7 @@
       
       <Border BorderBrush="{DynamicResource SystemControlHighlightBaseLowBrush}"
               BorderThickness="1" Padding="15">
-        <DatePicker Header="Pick a date">
+        <DatePicker >
           <DataValidationErrors.Error>
             <sys:Exception /> 
           </DataValidationErrors.Error>

src/Avalonia.Controls/DateTimePickers/DatePicker.cs

@@ -40,18 +40,6 @@ namespace Avalonia.Controls
             AvaloniaProperty.RegisterDirect<DatePicker, bool>(nameof(DayVisible),
                 x => x.DayVisible, (x, v) => x.DayVisible = v);
 
-        /// <summary>
-        /// Defines the <see cref="Header"/> Property
-        /// </summary>
-        public static readonly StyledProperty<object> HeaderProperty =
-            AvaloniaProperty.Register<DatePicker, object>(nameof(Header));
-
-        /// <summary>
-        /// Defines the <see cref="HeaderTemplate"/> Property
-        /// </summary>
-        public static readonly StyledProperty<IDataTemplate> HeaderTemplateProperty =
-            AvaloniaProperty.Register<DatePicker, IDataTemplate>(nameof(HeaderTemplate));
-
         /// <summary>
         /// Defines the <see cref="MaxYear"/> Property
         /// </summary>
@@ -152,24 +140,6 @@ namespace Avalonia.Controls
             }
         }
 
-        /// <summary>
-        /// Gets or sets the DatePicker header
-        /// </summary>
-        public object Header
-        {
-            get => GetValue(HeaderProperty);
-            set => SetValue(HeaderProperty, value);
-        }
-
-        /// <summary>
-        /// Gets or sets the header template
-        /// </summary>
-        public IDataTemplate HeaderTemplate
-        {
-            get => GetValue(HeaderTemplateProperty);
-            set => SetValue(HeaderTemplateProperty, value);
-        }
-
         /// <summary>
         /// Gets or sets the maximum year for the picker
         /// </summary>

src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml

@@ -424,7 +424,6 @@
     <!-- Resources for DatePicker.xaml-->
     <StaticResource x:Key="DatePickerSpacerFill" ResourceKey="SystemControlForegroundBaseLowBrush" />
     <StaticResource x:Key="DatePickerSpacerFillDisabled" ResourceKey="SystemControlDisabledBaseLowBrush" />
-    <StaticResource x:Key="DatePickerHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrush" ResourceKey="SystemControlForegroundBaseMediumBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightBaseMediumHighBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrushPressed" ResourceKey="SystemControlHighlightBaseMediumBrush" />
@@ -595,7 +594,6 @@
     <StaticResource x:Key="CalendarDatePickerTextForeground" ResourceKey="SystemControlForegroundBaseMediumBrush" />
     <StaticResource x:Key="CalendarDatePickerTextForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerTextForegroundSelected" ResourceKey="SystemControlForegroundBaseHighBrush" />
-    <StaticResource x:Key="CalendarDatePickerHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerBackground" ResourceKey="SystemControlBackgroundAltMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerBackgroundPointerOver" ResourceKey="SystemControlPageBackgroundAltMediumBrush" />
     <StaticResource x:Key="CalendarDatePickerBackgroundPressed" ResourceKey="SystemControlBackgroundBaseLowBrush" />

src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml

@@ -420,7 +420,6 @@
     <!-- Resources for DatePicker.xaml-->
     <StaticResource x:Key="DatePickerSpacerFill" ResourceKey="SystemControlForegroundBaseLowBrush" />
     <StaticResource x:Key="DatePickerSpacerFillDisabled" ResourceKey="SystemControlDisabledBaseLowBrush" />
-    <StaticResource x:Key="DatePickerHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrush" ResourceKey="SystemControlForegroundBaseMediumBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightBaseMediumHighBrush" />
     <StaticResource x:Key="DatePickerButtonBorderBrushPressed" ResourceKey="SystemControlHighlightBaseMediumBrush" />
@@ -589,7 +588,6 @@
     <StaticResource x:Key="CalendarDatePickerTextForeground" ResourceKey="SystemControlForegroundBaseMediumBrush" />
     <StaticResource x:Key="CalendarDatePickerTextForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerTextForegroundSelected" ResourceKey="SystemControlForegroundBaseHighBrush" />
-    <StaticResource x:Key="CalendarDatePickerHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerBackground" ResourceKey="SystemControlBackgroundAltMediumLowBrush" />
     <StaticResource x:Key="CalendarDatePickerBackgroundPointerOver" ResourceKey="SystemControlPageBackgroundAltMediumBrush" />
     <StaticResource x:Key="CalendarDatePickerBackgroundPressed" ResourceKey="SystemControlBackgroundBaseLowBrush" />

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

@@ -28,7 +28,6 @@
     </Border>
   </Design.PreviewWith>
 
-  <Thickness x:Key="DatePickerTopHeaderMargin">0,0,0,4</Thickness>
   <x:Double x:Key="DatePickerFlyoutPresenterHighlightHeight">40</x:Double>
   <x:Double x:Key="DatePickerFlyoutPresenterItemHeight">40</x:Double>
   <x:Double x:Key="DatePickerFlyoutPresenterAcceptDismissHostGridHeight">41</x:Double>
@@ -84,18 +83,8 @@
     <Setter Property="Template">
       <ControlTemplate>
         <DataValidationErrors>
-          <Grid Name="LayoutRoot" Margin="{TemplateBinding Padding}" RowDefinitions="Auto,*">
-            <ContentPresenter Name="HeaderContentPresenter" Grid.Row="0"
-                              Content="{TemplateBinding Header}"
-                              Foreground="{DynamicResource DatePickerHeaderForeground}"
-                              ContentTemplate="{TemplateBinding HeaderTemplate}"
-                              Margin="{DynamicResource DatePickerTopHeaderMargin}"
-                              MaxWidth="{DynamicResource DatePickerThemeMaxWidth}"
-                              HorizontalAlignment="Stretch"
-                              VerticalAlignment="Top"/>
-
+          <Grid Name="LayoutRoot" Margin="{TemplateBinding Padding}">
             <Button Name="PART_FlyoutButton"
-                    Grid.Row="1"
                     Theme="{StaticResource FluentDatePickerFlyoutButton}"
                     Foreground="{TemplateBinding Foreground}"
                     Background="{TemplateBinding Background}"

src/Avalonia.Themes.Simple/Controls/DatePicker.xaml

@@ -30,7 +30,6 @@
     </Border>
   </Design.PreviewWith>
 
-  <Thickness x:Key="DatePickerTopHeaderMargin">0,0,0,4</Thickness>
   <x:Double x:Key="DatePickerFlyoutPresenterHighlightHeight">40</x:Double>
   <x:Double x:Key="DatePickerFlyoutPresenterItemHeight">40</x:Double>
   <x:Double x:Key="DatePickerFlyoutPresenterAcceptDismissHostGridHeight">41</x:Double>
@@ -91,19 +90,9 @@
       <ControlTemplate>
         <DataValidationErrors>
           <Grid Name="LayoutRoot"
-                Margin="{TemplateBinding Padding}"
-                RowDefinitions="Auto,*">
-            <ContentPresenter Name="HeaderContentPresenter"
-                              Grid.Row="0"
-                              MaxWidth="{DynamicResource DatePickerThemeMaxWidth}"
-                              Margin="{DynamicResource DatePickerTopHeaderMargin}"
-                              HorizontalAlignment="Stretch"
-                              VerticalAlignment="Top"
-                              Content="{TemplateBinding Header}"
-                              ContentTemplate="{TemplateBinding HeaderTemplate}" />
+                Margin="{TemplateBinding Padding}">
 
             <Button Name="PART_FlyoutButton"
-                    Grid.Row="1"
                     MinWidth="{DynamicResource DatePickerThemeMinWidth}"
                     MaxWidth="{DynamicResource DatePickerThemeMaxWidth}"
                     HorizontalAlignment="Stretch"