WPF嵌套Scrollviewers-将控制权交还给上级scollviewer

Question

这是我的控制树的外观：

<window>
 <scrollviewer>
  <expander>
   <scrollviewer>
    <grid>
    </grid>
   </scrollviewer>
  </expander>
  <expander>
   <scrollviewer>
    <grid>
    </grid>
   </scrollviewer>
  </expander>
 </scrollviewer>
</window>

使用鼠标滚轮，该控件自动从父scrollviewer传递到子scrollviewer，但是当我滚动到该子scrollviewer的末尾时，该控件不会传递回父scorllviewer。我该如何实现？

扩展器，网格和滚动查看器是动态生成的。

Answer 1

我在应用程序中遇到了类似的麻烦。我通过依赖属性来纠正它，该属性也将捕获并传递事件给他的父母。这可以应用于其中具有滚动的任何控件。但是对我来说，我不需要验证是否已经发送给他的父母。您只需在OnValueChanged方法中添加一个验证，以确认滚动是在滚动的末尾还是在顶部，然后发送给其父级。

using System.Windows.Controls;

public static class SendMouseWheelToParent
{
   public static readonly DependencyProperty ScrollProperty
     = DependencyProperty.RegisterAttached("IsSendingMouseWheelEventToParent",
        typeof(bool),
        typeof(SendMouseWheelToParent),
        new FrameworkPropertyMetadata(OnValueChanged));

   /// <summary>
   /// Gets the IsSendingMouseWheelEventToParent for a given <see cref="TextBox"/>.
   /// </summary>
   /// <param name="control">
   /// The <see cref="TextBox"/> whose IsSendingMouseWheelEventToParent is to be retrieved.
   /// </param>
   /// <returns>
   /// The IsSendingMouseWheelEventToParent, or <see langword="null"/>
   /// if no IsSendingMouseWheelEventToParent has been set.
   /// </returns>
   public static bool? GetIsSendingMouseWheelEventToParent(Control control)
   {
       if (control == null)
           throw new ArgumentNullException("");

       return control.GetValue(ScrollProperty) as bool?;
   }

   /// <summary>
   /// Sets the IsSendingMouseWheelEventToParent for a given <see cref="TextBox"/>.
   /// </summary>
   /// <param name="control">
   /// The <see cref="TextBox"/> whose IsSendingMouseWheelEventToParent is to be set.
   /// </param>
   /// <param name="IsSendingMouseWheelEventToParent">
   /// The IsSendingMouseWheelEventToParent to set, or <see langword="null"/>
   /// to remove any existing IsSendingMouseWheelEventToParent from <paramref name="control"/>.
   /// </param>
   public static void SetIsSendingMouseWheelEventToParent(Control control, bool? sendToParent)
   {
       if (control == null)
           throw new ArgumentNullException("");

       control.SetValue(ScrollProperty, sendToParent);
   }

   private static void OnValueChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
   {
       var scrollViewer = dependencyObject as Control;
       bool? IsSendingMouseWheelEventToParent = e.NewValue as bool?;
       scrollViewer.PreviewMouseWheel -= scrollViewer_PreviewMouseWheel;

       if (IsSendingMouseWheelEventToParent != null && IsSendingMouseWheelEventToParent != false)
       {
         scrollViewer.SetValue(ScrollProperty, IsSendingMouseWheelEventToParent);
         scrollViewer.PreviewMouseWheel += scrollViewer_PreviewMouseWheel;
       }
   }


   private static void scrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
   {
       var scrollview = sender as Control;

       var eventArg = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta);
       eventArg.RoutedEvent = UIElement.MouseWheelEvent;
       eventArg.Source = sender;
       var parent = scrollview.Parent as UIElement;
       parent.RaiseEvent(eventArg);
   }
}

Answer 2

受Janick的答案和其他一些启发，我有一个实现，当内部的ScrollViewer（包括来自ListView，ListBox，DataGrid的）滚动超过其顶部/底部时，它滚动祖先的ScrollViewers。代码在我的answer here中是一个非常类似的问题。