Custom Listbox Scrollbar style Issue
I have the following xaml for WPF ListBox control. I have customized it so suit my UI requirements. However, the scrollbar thumb won't reach the top & bottom of the scrollbar. Also the thumb won't scroll if I click elsewhere on the vertical scrollbar track. Please help me resolve the issues. Any help is appreciated.
This is the snapshot of the ListBox control i have customized :
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
x:Class="MovieMessageBox.ListBoxStyles2"
x:Name="Window"
Title="ListBoxStyles2"
Width="370" Height="200">
<Window.Resources>
<SolidColorBrush x:Key="ListBorder" Color="#828790"/>
<Style x:Key="ListBoxStyle1" TargetType="{x:Type ListBox}">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"/>
<Setter Property="BorderBrush" Value="{StaticResource ListBorder}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
<Setter Property="ScrollViewer.PanningMode" Value="Both"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBox}">
<Grid>
<Rectangle Fill="Pink" RadiusX="10" RadiusY="10" Opacity="0.195" />
<Border CornerRadius="10" x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Padding="1" SnapsToDevicePixels="true">
<ScrollViewer Focusable="false" Padding="{TemplateBinding Padding}" Template="{DynamicResource ScrollViewerControlTemplate1}">
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</ScrollViewer>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
</Trigger>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ControlTemplate x:Key="ScrollViewerControlTemplate1" TargetType="{x:Type ScrollViewer}">
<Grid x:Name="Grid" Background="{TemplateBinding Background}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<ScrollContentPresenter x:Name="PART_ScrollContentPresenter" CanContentScroll="{TemplateBinding CanContentScroll}" CanHorizontallyScroll="False" CanVerticallyScroll="False" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="0" Margin="{TemplateBinding Padding}" />
<ScrollBar x:Name="PART_VerticalScrollBar" AutomationProperties.AutomationId="VerticalScrollBar" Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}" Minimum="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}" Style="{DynamicResource ScrollBarStyle1}"/>
</Grid>
</ControlTemplate>
<LinearGradientBrush x:Key="VerticalScrollBarBackground" EndPoint="1,0" StartPoint="0,0">
<GradientStop Color="#E1E1E1" Offset="0"/>
<GradientStop Color="#EDEDED" Offset="0.20"/>
<GradientStop Color="#EDEDED" Offset="0.80"/>
<GradientStop Color="#E3E3E3" Offset="1"/>
</LinearGradientBrush>
<SolidColorBrush x:Key="ScrollBarDisabledBackground" Color="#F4F4F4"/>
<Style x:Key="ScrollBarButton" TargetType="{x:Type RepeatButton}">
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="Focusable" Value="false"/>
<Setter Property="IsTabStop" Value="false"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Microsoft_Windows_Themes:ScrollChrome x:Name="Chrome" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}" SnapsToDevicePixels="true" Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph="{TemplateBinding Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="VerticalScrollBarPageButton" TargetType="{x:Type RepeatButton}">
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Focusable" Value="false"/>
<Setter Property="IsTabStop" Value="false"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Rectangle Fill="{TemplateBinding Background}" Height="{TemplateBinding Height}" Width="{TemplateBinding Width}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ScrollBarThumb" TargetType="{x:Type Thumb}">
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="IsTabStop" Value="false"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Thumb}">
<Rectangle Height="25" Width="8" Fill="White" RadiusX="5" RadiusY="5">
<Rectangle.Effect>
<DropShadowEffect ShadowDepth="0" BlurRadius="10" Color="White" />
</Rectangle.Effect>
</Rectangle>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<LinearGradientBrush x:Key="HorizontalScrollBarBackground" EndPoint="0,1" StartPoint="0,0">
<GradientStop Color="#E1E1E1" Offset="0"/>
<GradientStop Color="#EDEDED" Offset="0.20"/>
<GradientStop Color="#EDEDED" Offset="0.80"/>
<GradientStop Color="#E3E3E3" Offset="1"/>
</LinearGradientBrush>
<Style x:Key="HorizontalScrollBarPageButton" TargetType="{x:Type RepeatButton}">
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Focusable" Value="false"/>
<Setter Property="IsTabStop" Value="false"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Rectangle Fill="{TemplateBinding Background}" Height="{TemplateBinding Height}" Width="{TemplateBinding Width}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ScrollBarStyle1" TargetType="{x:Type ScrollBar}">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Stylus.IsPressAndHoldEnabled" Value="false"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="false"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="Width" Value="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}"/>
<Setter Property="MinWidth" Value="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ScrollBar}">
<Grid x:Name="Bg" Background="{TemplateBinding Background}" SnapsToDevicePixels="true">
<Border Width="1" Background="#FFFFFF" HorizontalAlignment="Center"/>
<Track x:Name="PART_Track" IsDirectionReversed="true" IsEnabled="{TemplateBinding IsMouseOver}">
<Track.Thumb>
<Thumb Style="{StaticResource ScrollBarThumb}" Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph="VerticalGripper"/>
</Track.Thumb>
</Track>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="Bg" Value="{StaticResource ScrollBarDisabledBackground}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Orientation" Value="Horizontal">
<Setter Property="Width" Value="Auto"/>
<Setter Property="MinWidth" Value="0"/>
<Setter Property="Height" Value="{DynamicResource {x:Static SystemParameters.HorizontalScrollBarHeightKey}}"/>
<Setter Property="MinHeight" Value="{DynamicResource {x:Static SystemParameters.HorizontalScrollBarHeightKey}}"/>
<Setter Property="Background" Value="{StaticResource HorizontalScrollBarBackground}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ScrollBar}">
<Grid x:Name="Bg" Background="{TemplateBinding Background}" SnapsToDevicePixels="true">
<Grid.ColumnDefinitions>
<ColumnDefinition MaxWidth="{DynamicResource {x:Static SystemParameters.HorizontalScrollBarButtonWidthKey}}"/>
<ColumnDefinition Width="0.00001*"/>
<ColumnDefinition MaxWidth="{DynamicResource {x:Static SystemParameters.HorizontalScrollBarButtonWidthKey}}"/>
</Grid.ColumnDefinitions>
<RepeatButton Command="{x:Static ScrollBar.LineLeftCommand}" IsEnabled="{TemplateBinding IsMouseOver}" Style="{StaticResource ScrollBarButton}" Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph="LeftArrow"/>
<Track x:Name="PART_Track" Grid.Column="1" IsEnabled="{TemplateBinding IsMouseOver}">
<Track.DecreaseRepeatButton>
<RepeatButton Command="{x:Static ScrollBar.PageLeftCommand}" Style="{StaticResource HorizontalScrollBarPageButton}"/>
</Track.DecreaseRepeatButton>
<Track.IncreaseRepeatButton>
<RepeatButton Command="{x:Static ScrollBar.PageRightCommand}" Style="{StaticResource HorizontalScrollBarPageButton}"/>
</Track.IncreaseRepeatButton>
<Track.Thumb>
<Thumb Style="{StaticResource ScrollBarThumb}" Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph="HorizontalGripper"/>
</Track.Thumb>
</Track>
<RepeatButton Grid.Column="2" Command="{x:Static ScrollBar.LineRightCommand}" IsEnabled="{TemplateBinding IsMouseOver}" Style="{StaticResource ScrollBarButton}" Microsoft_Windows_Themes:ScrollChrome.ScrollGlyph="RightArrow"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="Bg" Value="{StaticResource ScrollBarDisabledBackground}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
<Style TargetType="{x:Type ListBoxItem}">
<Setter Property="Foreground" Value="White" />
<Setter Property="Background" Value="Transparent"/>
<Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="Padding" Value="2,0,0,0"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBoxItem}">
<Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="true">
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected" Value="true"/>
<Condition Property="Selector.IsSelectionActive" Value="false"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
</MultiTrigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Window.Background>
<ImageBrush ImageSource="@aleaf-1920.jpg"/>
</Window.Background>
<Grid x:Name="LayoutRoot">
<ListBox HorizontalAlignment="Center" Height="150" Width="203" Style="{DynamicResource ListBoxStyle1}">
<ListBoxItem Content="India"/>
<ListBoxItem Content="America"/>
<ListBoxItem Content="Russia"/>
<ListBoxItem Content="Germany"/>
<ListBoxItem Content="France"/>
<ListBoxItem Content="Australia"/>
<ListBoxItem Content="Thailand"/>
<ListBoxItem Content="England"/>
<ListBoxItem Content="Holand"/>
<ListBoxItem Content="Poland"/>
<ListBoxItem Content="Lesotho"/>
<ListBoxItem Content="Tanzania"/>
</ListBox>
</Grid>
</Window>
Answer
The behaviour you're seeing is because the scrollbar thumb is proportional. Compare the two thumbs in the image below.
The thumb is actually using 75% of the height of the scrollbar because the list box is displaying 9 of the 12 items., but you have set the height of your custom thumb to 25. Remove the "height=25" attribute and it will behave properly.