diff --git a/src/Net_40/HandyControl_Net_40/Themes/Theme.xaml b/src/Net_40/HandyControl_Net_40/Themes/Theme.xaml
index 6402103d..0df7730f 100644
--- a/src/Net_40/HandyControl_Net_40/Themes/Theme.xaml
+++ b/src/Net_40/HandyControl_Net_40/Themes/Theme.xaml
@@ -7860,7 +7860,7 @@
 							<RowDefinition Height="16" />
 							<RowDefinition />
 						</Grid.RowDefinitions>
-						<Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
+						<Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="1" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
 							<Border.RenderTransform>
 								<TransformGroup>
 									<TranslateTransform X="5" Y="5" />
@@ -7892,9 +7892,7 @@
 			<Setter.Value>
 				<ControlTemplate TargetType="hc:CoverView">
 					<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
-						<ScrollViewer>
-							<WrapPanel x:Name="PART_Panel" />
-						</ScrollViewer>
+						<WrapPanel x:Name="PART_Panel" />
 					</Border>
 				</ControlTemplate>
 			</Setter.Value>
diff --git a/src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs b/src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs
index 64eb1888..301cc8e1 100644
--- a/src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs
@@ -341,7 +341,7 @@ namespace HandyControl.Controls
             "ShowSelectAllButton", typeof(bool), typeof(DataGridAttach), new PropertyMetadata(ValueBoxes.TrueBox));
 
         public static void SetShowSelectAllButton(DependencyObject element, bool value)
-            => element.SetValue(ShowSelectAllButtonProperty, value);
+            => element.SetValue(ShowSelectAllButtonProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetShowSelectAllButton(DependencyObject element)
             => (bool) element.GetValue(ShowSelectAllButtonProperty);
diff --git a/src/Shared/HandyControl_Shared/Controls/Attach/ScrollViewerAttach.cs b/src/Shared/HandyControl_Shared/Controls/Attach/ScrollViewerAttach.cs
index f78e4545..67306295 100644
--- a/src/Shared/HandyControl_Shared/Controls/Attach/ScrollViewerAttach.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Attach/ScrollViewerAttach.cs
@@ -11,7 +11,7 @@ namespace HandyControl.Controls
             "AutoHide", typeof(bool), typeof(ScrollViewerAttach), new FrameworkPropertyMetadata(ValueBoxes.TrueBox, FrameworkPropertyMetadataOptions.Inherits));
 
         public static void SetAutoHide(DependencyObject element, bool value)
-            => element.SetValue(AutoHideProperty, value);
+            => element.SetValue(AutoHideProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetAutoHide(DependencyObject element)
             => (bool) element.GetValue(AutoHideProperty);
diff --git a/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverView.cs b/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverView.cs
index ada57091..6f255395 100644
--- a/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverView.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverView.cs
@@ -35,7 +35,7 @@ namespace HandyControl.Controls
             {
                 if (_selectedItem == null)
                 {
-                    item.IsSelected = true;
+                    item.SetCurrentValue(SelectableItem.IsSelectedProperty, ValueBoxes.TrueBox);
                     _selectedItem = item;
                     if (_viewContent != null)
                     {
@@ -49,8 +49,8 @@ namespace HandyControl.Controls
 
                 if (!Equals(_selectedItem, item))
                 {
-                    _selectedItem.IsSelected = false;
-                    item.IsSelected = true;
+                    _selectedItem.SetCurrentValue(SelectableItem.IsSelectedProperty, ValueBoxes.FalseBox);
+                    item.SetCurrentValue(SelectableItem.IsSelectedProperty, ValueBoxes.TrueBox);
                     _selectedItem = item;
                     if (_viewContent != null)
                     {
@@ -67,7 +67,7 @@ namespace HandyControl.Controls
                     _viewContent.ContentTemplate = null;
                     UpdateCoverViewContent(false);
                 }
-                _selectedItem.IsSelected = false;
+                _selectedItem.SetCurrentValue(SelectableItem.IsSelectedProperty, ValueBoxes.FalseBox);
                 _selectedItem = null;
             }
         }
@@ -218,6 +218,12 @@ namespace HandyControl.Controls
             {
                 ItemsHost.Children.Remove(_viewContent);
             }
+
+            if (_selectedItem == null)
+            {
+                return;
+            }
+
             var total = _entryDic.Count + 1;
             var totalRow = total / Groups + (total % Groups > 0 ? 1 : 0);
             if (total <= Groups)
diff --git a/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverViewContent.cs b/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverViewContent.cs
index 689d9b00..626d682f 100644
--- a/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverViewContent.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Cover/CoverView/CoverViewContent.cs
@@ -9,7 +9,7 @@ namespace HandyControl.Controls
 {
     [TemplatePart(Name = ElementTriangle, Type = typeof(FrameworkElement))]
     [TemplatePart(Name = ElementContent, Type = typeof(FrameworkElement))]
-    internal class CoverViewContent : ContentControl
+    public class CoverViewContent : ContentControl
     {
         private const string ElementTriangle = "PART_Triangle";
 
diff --git a/src/Shared/HandyControl_Shared/Themes/Styles/Base/CoverViewBaseStyle.xaml b/src/Shared/HandyControl_Shared/Themes/Styles/Base/CoverViewBaseStyle.xaml
index 5458edbf..442852af 100644
--- a/src/Shared/HandyControl_Shared/Themes/Styles/Base/CoverViewBaseStyle.xaml
+++ b/src/Shared/HandyControl_Shared/Themes/Styles/Base/CoverViewBaseStyle.xaml
@@ -29,7 +29,7 @@
                             <RowDefinition Height="16"/>
                             <RowDefinition/>
                         </Grid.RowDefinitions>
-                        <Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
+                        <Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="1" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
                             <Border.RenderTransform>
                                 <TransformGroup>
                                     <TranslateTransform X="5" Y="5"/>
@@ -62,13 +62,11 @@
             <Setter.Value>
                 <ControlTemplate TargetType="hc:CoverView">
                     <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
-                        <ScrollViewer>
-                            <WrapPanel x:Name="PART_Panel"/>
-                        </ScrollViewer>
+                        <WrapPanel x:Name="PART_Panel"/>
                     </Border>
                 </ControlTemplate>
             </Setter.Value>
         </Setter>
     </Style>
 
-</ResourceDictionary>
\ No newline at end of file
+</ResourceDictionary>
diff --git a/src/Shared/HandyControl_Shared/Themes/Theme.xaml b/src/Shared/HandyControl_Shared/Themes/Theme.xaml
index fe27287d..df5d3916 100644
--- a/src/Shared/HandyControl_Shared/Themes/Theme.xaml
+++ b/src/Shared/HandyControl_Shared/Themes/Theme.xaml
@@ -7978,7 +7978,7 @@
 							<RowDefinition Height="16" />
 							<RowDefinition />
 						</Grid.RowDefinitions>
-						<Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
+						<Border x:Name="PART_Triangle" Visibility="Visible" Grid.Row="0" Width="30" Height="30" BorderThickness="1" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.RowSpan="2">
 							<Border.RenderTransform>
 								<TransformGroup>
 									<TranslateTransform X="5" Y="5" />
@@ -8010,9 +8010,7 @@
 			<Setter.Value>
 				<ControlTemplate TargetType="hc:CoverView">
 					<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
-						<ScrollViewer>
-							<WrapPanel x:Name="PART_Panel" />
-						</ScrollViewer>
+						<WrapPanel x:Name="PART_Panel" />
 					</Border>
 				</ControlTemplate>
 			</Setter.Value>