更改鼠标悬停时 DataGrid 滚动条的可见性？

Question

如何在 DataGrid 的 IsMouseOver 属性上切换 DataGrid 滚动条的可见性？

我想让滚动条在鼠标悬停在 DataGrid 上时可见，而在鼠标移出 DataGrid 时不可见。如果有 XAML 示例，我们将不胜感激。

Answer 1

我会应用一种新的样式，如下所示：

<Style x:Key="dataGridStyle" TargetType={x:Type DataGrid}>
   <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden"/>
   <Style.Triggers>
       <Trigger Property="IsMouseOver" Value="True">
           <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
       </Trigger>
   </Style.Triggers>
 </Style>

Answer 2

创建一个值转换器：

[ValueConversion(typeof(bool), typeof(ScrollBarVisibility))]
sealed class MouseOverToScrollBarVisibility : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return ((bool)value) ? ScrollBarVisibility.Auto : ScrollBarVisibility.Hidden;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

在资源中的某处声明它：

<Window.Resources>
    <local:MouseOverToScrollBarVisibility x:Key="MouseOverToScrollBarVisibility" />
</Window.Resources>

并使用它将 ScrollViewer.VerticalScrollBarVisibility 属性绑定到 IsMouseOver 属性：

<DataGrid ScrollViewer.VerticalScrollBarVisibility=
          "{Binding IsMouseOver,
                    RelativeSource={RelativeSource Self},
                    Converter={StaticResource MouseOverToScrollBarVisibility}}">
</DataGrid>