滚动视图：Scrollviwer 或者 listview 等， 可以添加一个 滚动到选中view 的 附加属性吗？

[heartacker]

大概是这个意思：
https://mattduffield.wordpress.com/2011/01/15/automatically-scrolling-to-a-selected-item-in-a-scrollviewer-in-silverlight/

[Hakoyu]

我之前好像写了个差不多的 你可以用用
需要 Behaviors

public class ScrollToControlAction : TriggerAction<FrameworkElement>
{
    public static readonly DependencyProperty ScrollViewerProperty = DependencyProperty.Register(
        "ScrollViewer",
        typeof(ScrollViewer),
        typeof(ScrollToControlAction)
    );

    public static readonly DependencyProperty TargetControlProperty = DependencyProperty.Register(
        "TargetControl",
        typeof(FrameworkElement),
        typeof(ScrollToControlAction)
    );

    public ScrollViewer ScrollViewer
    {
        get => (ScrollViewer)GetValue(ScrollViewerProperty);
        set => SetValue(ScrollViewerProperty, value);
    }

    public FrameworkElement TargetControl
    {
        get => (FrameworkElement)GetValue(TargetControlProperty);
        set => SetValue(TargetControlProperty, value);
    }

    protected override void Invoke(object parameter)
    {
        if (TargetControl is null || ScrollViewer is null)
            throw new ArgumentNullException($"{ScrollViewer} or {TargetControl} cannot be null");
        // 检查指定的控件是否在指定的 ScrollViewer 中
        var result = TargetControl.FindVisuaParent<ScrollViewer>();
        if (result is null || result != ScrollViewer)
            throw new Exception("The TargetControl is not in the target ScrollViewer");

        // 获取要定位之前 ScrollViewer 目前的滚动位置
        var currentScrollPosition = ScrollViewer.VerticalOffset;
        var point = new Point(0, currentScrollPosition);

        // 计算出目标位置并滚动
        var targetPosition = TargetControl.TransformToVisual(ScrollViewer).Transform(point);
        ScrollViewer.ScrollToVerticalOffset(targetPosition.Y);
    }

    public static T FindVisuaParent<T>(this DependencyObject reference)
        where T : DependencyObject
    {
        var temp = reference;
        while ((temp = VisualTreeHelper.GetParent(temp)) is not null)
        {
            if (temp is T t)
                return t;
        }
        return null!;
    }
}

示例

  <Grid>
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="Auto" MinWidth="100" />
      <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <StackPanel>
      <Button Content="1">
        <i:Interaction.Triggers>
          <i:EventTrigger EventName="Click">
            <local:ScrollToControlAction ScrollViewer="{Binding ElementName=ScrollViewer}" TargetControl="{Binding ElementName=Button_4}" />
          </i:EventTrigger>
        </i:Interaction.Triggers>
      </Button>
    </StackPanel>
    <ScrollViewer
      x:Name="ScrollViewer"
      Grid.Column="1"
      VerticalScrollBarVisibility="Auto">
      <StackPanel>
        <Button Height="100" Content="111" />
        <Button Height="100" Content="222" />
        <Button Height="100" Content="333" />
        <Button
          x:Name="Button_4"
          Height="100"
          Content="444" />
        <Button
          x:Name="Button_5"
          Height="100"
          Content="555" />
      </StackPanel>
    </ScrollViewer>
  </Grid>