Esempio di ControlTemplate del controllo ScrollBar

  • Articolo

Aggiornamento: novembre 2007

I controlli disponibili in Windows Presentation Foundation (WPF) includono un oggetto ControlTemplate che contiene la relativa struttura ad albero visuale. È possibile modificare la struttura e l'aspetto di un controllo modificando il relativo oggetto ControlTemplate. Non è possibile sostituire solo una parte della struttura ad albero visuale di un controllo. Per modificare la struttura ad albero visuale di un controllo, è necessario impostare la proprietà Template di tale controllo sul relativo oggetto ControlTemplate nuovo e completo.

In questo argomento viene illustrato l'oggetto ControlTemplate del controllo ScrollBar di WPF.

Nel presente argomento sono contenute le seguenti sezioni.

  • Prerequisiti
  • Esempio di ControlTemplate del controllo ScrollBar
  • Argomenti correlati

Prerequisiti

Per eseguire gli esempi di questo argomento, è necessario disporre di conoscenze su come scrivere applicazioni WPF. Per ulteriori informazioni, vedere Guida introduttiva a Windows Presentation Foundation. È inoltre necessario comprendere l'utilizzo degli stili in WPF. Per ulteriori informazioni, vedere Applicazione di stili e modelli.

Esempio di ControlTemplate del controllo ScrollBar

Anche se questo esempio contiene tutti gli elementi definiti nell'oggetto ControlTemplate di un controllo ScrollBar per impostazione predefinita, i valori specifici devono essere considerati come esempi.

<Style x:Key="ScrollBarLineButton" TargetType="{x:Type RepeatButton}">
  <Setter Property="SnapsToDevicePixels" Value="True"/>
  <Setter Property="OverridesDefaultStyle" Value="true"/>
  <Setter Property="Focusable" Value="false"/>
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type RepeatButton}">
        <Border 
          Name="Border"
          Margin="1" 
          CornerRadius="2" 
          Background="{StaticResource NormalBrush}"
          BorderBrush="{StaticResource NormalBorderBrush}"
          BorderThickness="1">
          <Path 
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Fill="{StaticResource GlyphBrush}"
            Data="{Binding Path=Content,RelativeSource={RelativeSource TemplatedParent}}" />
        </Border>
        <ControlTemplate.Triggers>
          <Trigger Property="IsPressed" Value="true">
            <Setter TargetName="Border" Property="Background" Value="{StaticResource PressedBrush}" />
          </Trigger>
          <Trigger Property="IsEnabled" Value="false">
            <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
          </Trigger>
        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

<Style x:Key="ScrollBarPageButton" TargetType="{x:Type RepeatButton}">
  <Setter Property="SnapsToDevicePixels" Value="True"/>
  <Setter Property="OverridesDefaultStyle" Value="true"/>
  <Setter Property="IsTabStop" Value="false"/>
  <Setter Property="Focusable" Value="false"/>
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type RepeatButton}">
        <Border Background="Transparent" />
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

<Style x:Key="ScrollBarThumb" TargetType="{x:Type Thumb}">
  <Setter Property="SnapsToDevicePixels" Value="True"/>
  <Setter Property="OverridesDefaultStyle" Value="true"/>
  <Setter Property="IsTabStop" Value="false"/>
  <Setter Property="Focusable" Value="false"/>
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type Thumb}">
        <Border 
          CornerRadius="2" 
          Background="{TemplateBinding Background}"
          BorderBrush="{TemplateBinding BorderBrush}"
          BorderThickness="1" />
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

<ControlTemplate x:Key="VerticalScrollBar" TargetType="{x:Type ScrollBar}">
  <Grid >
    <Grid.RowDefinitions>
      <RowDefinition MaxHeight="18"/>
      <RowDefinition Height="0.00001*"/>
      <RowDefinition MaxHeight="18"/>
    </Grid.RowDefinitions>
    <Border
      Grid.RowSpan="3"
      CornerRadius="2" 
      Background="#F0F0F0" />
    <RepeatButton 
      Grid.Row="0"                           
      Style="{StaticResource ScrollBarLineButton}"
      Height="18"
      Command="ScrollBar.LineUpCommand"
      Content="M 0 4 L 8 4 L 4 0 Z" />
    <Track 
      Name="PART_Track"
      Grid.Row="1"
      IsDirectionReversed="true">
      <Track.DecreaseRepeatButton>
        <RepeatButton 
          Style="{StaticResource ScrollBarPageButton}"
          Command="ScrollBar.PageUpCommand" />
      </Track.DecreaseRepeatButton>
      <Track.Thumb>
        <Thumb 
          Style="{StaticResource ScrollBarThumb}" 
          Margin="1,0,1,0"  
          Background="{StaticResource HorizontalNormalBrush}"
          BorderBrush="{StaticResource HorizontalNormalBorderBrush}" />
      </Track.Thumb>
      <Track.IncreaseRepeatButton>
        <RepeatButton 
          Style="{StaticResource ScrollBarPageButton}"
          Command="ScrollBar.PageDownCommand" />
      </Track.IncreaseRepeatButton>
    </Track>
    <RepeatButton 
      Grid.Row="3" 
      Style="{StaticResource ScrollBarLineButton}"
      Height="18"
      Command="ScrollBar.LineDownCommand"
      Content="M 0 0 L 4 4 L 8 0 Z"/>
  </Grid>
</ControlTemplate>

<ControlTemplate x:Key="HorizontalScrollBar" TargetType="{x:Type ScrollBar}">
  <Grid >
    <Grid.ColumnDefinitions>
      <ColumnDefinition MaxWidth="18"/>
      <ColumnDefinition Width="0.00001*"/>
      <ColumnDefinition MaxWidth="18"/>
    </Grid.ColumnDefinitions>
    <Border
      Grid.ColumnSpan="3"
      CornerRadius="2" 
      Background="#F0F0F0" />
    <RepeatButton 
      Grid.Column="0"                           
      Style="{StaticResource ScrollBarLineButton}"
      Width="18"
      Command="ScrollBar.LineLeftCommand"
      Content="M 4 0 L 4 8 L 0 4 Z" />
    <Track 
      Name="PART_Track"
      Grid.Column="1"
      IsDirectionReversed="False">
      <Track.DecreaseRepeatButton>
        <RepeatButton 
          Style="{StaticResource ScrollBarPageButton}"
          Command="ScrollBar.PageLeftCommand" />
      </Track.DecreaseRepeatButton>
      <Track.Thumb>
        <Thumb 
          Style="{StaticResource ScrollBarThumb}" 
          Margin="0,1,0,1"  
          Background="{StaticResource NormalBrush}"
          BorderBrush="{StaticResource NormalBorderBrush}" />
      </Track.Thumb>
      <Track.IncreaseRepeatButton>
        <RepeatButton 
          Style="{StaticResource ScrollBarPageButton}"
          Command="ScrollBar.PageRightCommand" />
      </Track.IncreaseRepeatButton>
    </Track>
    <RepeatButton 
      Grid.Column="3" 
      Style="{StaticResource ScrollBarLineButton}"
      Width="18"
      Command="ScrollBar.LineRightCommand"
      Content="M 0 0 L 4 4 L 0 8 Z"/>
  </Grid>
</ControlTemplate>

<Style x:Key="{x:Type ScrollBar}" TargetType="{x:Type ScrollBar}">
  <Setter Property="SnapsToDevicePixels" Value="True"/>
  <Setter Property="OverridesDefaultStyle" Value="true"/>
  <Style.Triggers>
    <Trigger Property="Orientation" Value="Horizontal">
      <Setter Property="Width" Value="Auto"/>
      <Setter Property="Height" Value="18" />
      <Setter Property="Template" Value="{StaticResource HorizontalScrollBar}" />
    </Trigger>
    <Trigger Property="Orientation" Value="Vertical">
      <Setter Property="Width" Value="18"/>
      <Setter Property="Height" Value="Auto" />
      <Setter Property="Template" Value="{StaticResource VerticalScrollBar}" />
    </Trigger>
  </Style.Triggers>
</Style>

Nell'esempio precedente vengono utilizzate una o più delle risorse seguenti.

<!-- Fill Brushes -->

<LinearGradientBrush x:Key="NormalBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#FFF" Offset="0.0"/>
      <GradientStop Color="#CCC" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="HorizontalNormalBrush" StartPoint="0,0" EndPoint="1,0">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#FFF" Offset="0.0"/>
      <GradientStop Color="#CCC" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="LightBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#FFF" Offset="0.0"/>
      <GradientStop Color="#EEE" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="HorizontalLightBrush" StartPoint="0,0" EndPoint="1,0">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#FFF" Offset="0.0"/>
      <GradientStop Color="#EEE" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="DarkBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#FFF" Offset="0.0"/>
      <GradientStop Color="#AAA" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="PressedBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#BBB" Offset="0.0"/>
      <GradientStop Color="#EEE" Offset="0.1"/>
      <GradientStop Color="#EEE" Offset="0.9"/>
      <GradientStop Color="#FFF" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<SolidColorBrush x:Key="DisabledForegroundBrush" Color="#888" />

<SolidColorBrush x:Key="DisabledBackgroundBrush" Color="#EEE" />

<SolidColorBrush x:Key="WindowBackgroundBrush" Color="#FFF" />

<SolidColorBrush x:Key="SelectedBackgroundBrush" Color="#DDD" />

<!-- Border Brushes -->

<LinearGradientBrush x:Key="NormalBorderBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#CCC" Offset="0.0"/>
      <GradientStop Color="#444" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="HorizontalNormalBorderBrush" StartPoint="0,0" EndPoint="1,0">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#CCC" Offset="0.0"/>
      <GradientStop Color="#444" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="DefaultedBorderBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#777" Offset="0.0"/>
      <GradientStop Color="#000" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<LinearGradientBrush x:Key="PressedBorderBrush" StartPoint="0,0" EndPoint="0,1">
  <GradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#444" Offset="0.0"/>
      <GradientStop Color="#888" Offset="1.0"/>
    </GradientStopCollection>
  </GradientBrush.GradientStops>
</LinearGradientBrush>

<SolidColorBrush x:Key="DisabledBorderBrush" Color="#AAA" />

<SolidColorBrush x:Key="SolidBorderBrush" Color="#888" />

<SolidColorBrush x:Key="LightBorderBrush" Color="#AAA" />

<!-- Miscellaneous Brushes -->
<SolidColorBrush x:Key="GlyphBrush" Color="#444" />

<SolidColorBrush x:Key="LightColorBrush" Color="#DDD" />

Per l'esempio completo, vedere Esempio di applicazione di stili con ControlTemplate.

Vedere anche

Concetti

Linee guida per la progettazione di controlli a cui è possibile applicare degli stili

Altre risorse

Esempi di ControlTemplate