Question

I have a WPF application that runs on a touch screen computer. I’d like to change all of the scroll bars in the app to be much wider. Is there a way to do that globally?

Answer 1

Yo have to override the default template of scrollViewer to increase the width of vertical scrollbar. To apply the template across all your scrollbars put the override style in your App resources –

<Style TargetType="{x:Type ScrollViewer}">
  <Setter Property="OverridesDefaultStyle" Value="True"/>
  <Setter Property="HorizontalContentAlignment" Value="Left" />
  <Setter Property="VerticalContentAlignment" Value="Top" />
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type ScrollViewer}">
        <Grid>
          <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition/>
          </Grid.ColumnDefinitions>
          <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition Height="Auto"/>
          </Grid.RowDefinitions>

          <ScrollContentPresenter Grid.Column="1"/>

          <ScrollBar Name="PART_VerticalScrollBar"
            Value="{TemplateBinding VerticalOffset}"
            Width="40"
            Maximum="{TemplateBinding ScrollableHeight}"
            ViewportSize="{TemplateBinding ViewportHeight}"
            Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"/>
          <ScrollBar Name="PART_HorizontalScrollBar"
            Orientation="Horizontal"
            Grid.Row="1"
            Grid.Column="1"
            Value="{TemplateBinding HorizontalOffset}"
            Maximum="{TemplateBinding ScrollableWidth}"
            ViewportSize="{TemplateBinding ViewportWidth}"
            Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"/>

        </Grid>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

You can set width of 'PART_VerticalScrollBar' to your desired width (say 40 as in example above).Placing this style under Application Resources (App.xaml) makes it applied across complete application.