Esempio di ControlTemplate del controllo Expander

  • 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 Expander di WPF.

Nel presente argomento sono contenute le seguenti sezioni.

  • Prerequisiti
  • Esempio di ControlTemplate del controllo Expander
  • 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 Expander

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

<ControlTemplate x:Key="ExpanderToggleButton" TargetType="ToggleButton">
  <Border
    Name="Border" 
    CornerRadius="2,0,0,0"
    Background="Transparent"
    BorderBrush="{StaticResource NormalBorderBrush}"
    BorderThickness="0,0,1,0">
    <Path 
      Name="Arrow"
      Fill="{StaticResource GlyphBrush}"
      HorizontalAlignment="Center"
      VerticalAlignment="Center"
      Data="M 0 0 L 4 4 L 8 0 Z"/>
  </Border>
  <ControlTemplate.Triggers>
    <Trigger Property="ToggleButton.IsMouseOver" Value="true">
      <Setter TargetName="Border" Property="Background"
              Value="{StaticResource DarkBrush}" />
    </Trigger>
    <Trigger Property="IsPressed" Value="true">
      <Setter TargetName="Border" Property="Background"
              Value="{StaticResource PressedBrush}" />
    </Trigger>
    <Trigger Property="IsChecked" Value="true">
      <Setter TargetName="Arrow" Property="Data"
              Value="M 0 4 L 4 0 L 8 4 Z" />
    </Trigger>
    <Trigger Property="IsEnabled" Value="False">
      <Setter TargetName="Border" Property="Background"
              Value="{StaticResource DisabledBackgroundBrush}" />
      <Setter TargetName="Border" Property="BorderBrush"
              Value="{StaticResource DisabledBorderBrush}" />
      <Setter Property="Foreground"
              Value="{StaticResource DisabledForegroundBrush}"/>
      <Setter TargetName="Arrow" Property="Fill"
              Value="{StaticResource DisabledForegroundBrush}" />
    </Trigger>
  </ControlTemplate.Triggers>
</ControlTemplate>

<Style TargetType="Expander">
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="Expander">
        <Grid>
          <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Name="ContentRow" Height="0"/>
          </Grid.RowDefinitions>
          <Border 
            Name="Border" 
            Grid.Row="0" 
            Background="{StaticResource LightBrush}"
            BorderBrush="{StaticResource NormalBorderBrush}"
            BorderThickness="1" 
            CornerRadius="2,2,0,0" >
            <Grid>
              <Grid.ColumnDefinitions>
                <ColumnDefinition Width="20" />
                <ColumnDefinition Width="*" />
              </Grid.ColumnDefinitions>
              <ToggleButton
                IsChecked="{Binding Path=IsExpanded,Mode=TwoWay,
                                    RelativeSource={RelativeSource TemplatedParent}}"
                OverridesDefaultStyle="True" 
                Template="{StaticResource ExpanderToggleButton}" 
                Background="{StaticResource NormalBrush}" />
              <ContentPresenter 
                Grid.Column="1"
                Margin="4" 
                ContentSource="Header" 
                RecognizesAccessKey="True" />
            </Grid>
          </Border>
          <Border 
            Name="Content" 
            Grid.Row="1" 
            Background="{StaticResource WindowBackgroundBrush}"
            BorderBrush="{StaticResource SolidBorderBrush}" 
            BorderThickness="1,0,1,1" 
            CornerRadius="0,0,2,2" >
            <ContentPresenter Margin="4" />
          </Border>
        </Grid>
        <ControlTemplate.Triggers>
          <Trigger Property="IsExpanded" Value="True">
            <Setter TargetName="ContentRow" Property="Height"
                    Value="{Binding ElementName=Content,Path=DesiredHeight}" />
          </Trigger>
          <Trigger Property="IsEnabled" Value="False">
            <Setter TargetName="Border" Property="Background"
                    Value="{StaticResource DisabledBackgroundBrush}" />
            <Setter TargetName="Border" Property="BorderBrush"
                    Value="{StaticResource DisabledBorderBrush}" />
            <Setter Property="Foreground"
                    Value="{StaticResource DisabledForegroundBrush}"/>
          </Trigger>

        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</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