wpf - 如何链接滚动条和滚动查看器

Question

我目前有两个 ScrollViewer，它们包含同一集合的备用 View 。我通过处理 ScrollChanged 事件并使用 ScrollToVerticalOffset 将两个滚动查看器的滚动绑定(bind)在一起。

出于演示的原因，我将两个 ScrollViewer 滚动条都设置为隐藏，并希望从单独的 ScrollBar 控制它们。

这似乎并不简单。我记得几个月前看过一篇关于它的博客，但我再也找不到了。

任何人都可以为我指出一些有用资源的方向，或者让我朝着正确的方向插入它如何实现。

提前致谢。

Answer 1

太好了，正是我需要的。我扩展了一点，以便也可以使用依赖属性从 xaml 设置滚动查看器。在xml中:

<local:BindableScrollBar BoundScrollViewer ="{Binding ElementName=ScrollViewer}"  Orientation="Vertical" />

代码:

    /// <summary>
/// An extended scrollbar that can be bound to an external scrollviewer.
/// </summary>
public class BindableScrollBar : ScrollBar
{
    public ScrollViewer BoundScrollViewer
    {
        get { return (ScrollViewer)GetValue(BoundScrollViewerProperty); }
        set { SetValue(BoundScrollViewerProperty, value); }
    }

    // Using a DependencyProperty as the backing store for BoundScrollViewer.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty BoundScrollViewerProperty =
        DependencyProperty.Register("BoundScrollViewer", typeof(ScrollViewer), typeof(BindableScrollBar), new FrameworkPropertyMetadata(null, new PropertyChangedCallback(OnBoundScrollViewerPropertyChanged)));

    private static void OnBoundScrollViewerPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        BindableScrollBar sender = d as BindableScrollBar;
        if (sender != null && e.NewValue != null)
        {
            sender.UpdateBindings();
        }
    }



    /// <summary>
    /// Initializes a new instance of the <see cref="BindableScrollBar"/> class.
    /// </summary>
    /// <param name="scrollViewer">The scroll viewer.</param>
    /// <param name="o">The o.</param>
    public BindableScrollBar(ScrollViewer scrollViewer, Orientation o)
        : base()
    { 
        this.Orientation = o;
        BoundScrollViewer = scrollViewer; 
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="BindableScrollBar"/> class.
    /// </summary>
    public BindableScrollBar() : base() { }

    private void UpdateBindings()
    {
        AddHandler(ScrollBar.ScrollEvent, new ScrollEventHandler(OnScroll));
        BoundScrollViewer.AddHandler(ScrollViewer.ScrollChangedEvent, new ScrollChangedEventHandler(BoundScrollChanged));
        Minimum = 0;
        if (Orientation == Orientation.Horizontal)
        {
            SetBinding(ScrollBar.MaximumProperty, (new Binding("ScrollableWidth") { Source = BoundScrollViewer, Mode = BindingMode.OneWay }));
            SetBinding(ScrollBar.ViewportSizeProperty, (new Binding("ViewportWidth") { Source = BoundScrollViewer, Mode = BindingMode.OneWay }));
        }
        else 
        {
            this.SetBinding(ScrollBar.MaximumProperty, (new Binding("ScrollableHeight") { Source = BoundScrollViewer, Mode = BindingMode.OneWay }));
            this.SetBinding(ScrollBar.ViewportSizeProperty, (new Binding("ViewportHeight") { Source = BoundScrollViewer, Mode = BindingMode.OneWay })); 
        } 
        LargeChange = 242; 
        SmallChange = 16;
    }

    private void BoundScrollChanged(object sender, ScrollChangedEventArgs e) 
    { 
        switch (this.Orientation) 
        { 
            case Orientation.Horizontal:
                this.Value = e.HorizontalOffset;
            break;
            case Orientation.Vertical:
                this.Value = e.VerticalOffset; 
                break; 
            default:
                break; 
        }
    }

    private void OnScroll(object sender, ScrollEventArgs e) 
    {
        switch (this.Orientation) 
        {
            case Orientation.Horizontal:
                this.BoundScrollViewer.ScrollToHorizontalOffset(e.NewValue);
                break;
            case Orientation.Vertical:
                this.BoundScrollViewer.ScrollToVerticalOffset(e.NewValue);
                break; 
            default: 
                break; 
        } 
    }
}