我有一个用户控件，它包含一个滚动视图器和一堆子控件，例如文本框、单选按钮和列表框等。我可以使用鼠标滚轮来滚动父滚动视图器，直到鼠标停在列表框内，然后鼠标滚轮事件开始传递给列表框。
有没有办法让列表框将这些事件发送回父控件？像这个问题建议的那样（当鼠标位于 ScrollViewer 的子控件上时鼠标滚轮无效），将列表框从父控件中删除并不是一个解决方案。
我已经尝试过：
private void ListBox_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
}
但那也没有起作用。
谢谢
“因此，我想出了以下的 IgnoreMouseWheelBehavior。从技术上讲，它并不是忽略鼠标滚轮事件，而是将该事件"转发"回到 ListBox 上并向外传递。请查看它。”
/// <summary>
/// Captures and eats MouseWheel events so that a nested ListBox does not
/// prevent an outer scrollable control from scrolling.
/// </summary>
public sealed class IgnoreMouseWheelBehavior : Behavior<UIElement>
{
protected override void OnAttached( )
{
base.OnAttached( );
AssociatedObject.PreviewMouseWheel += AssociatedObject_PreviewMouseWheel ;
}
protected override void OnDetaching( )
{
AssociatedObject.PreviewMouseWheel -= AssociatedObject_PreviewMouseWheel;
base.OnDetaching( );
}
void AssociatedObject_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
var e2 = new MouseWheelEventArgs(e.MouseDevice,e.Timestamp,e.Delta);
e2.RoutedEvent = UIElement.MouseWheelEvent;
AssociatedObject.RaiseEvent(e2);
}
}
以下是在 XAML 中使用它的方法。
<ScrollViewer Name="IScroll">
<ListBox Name="IDont">
<i:Interaction.Behaviors>
<local:IgnoreMouseWheelBehavior />
</i:Interaction.Behaviors>
</ListBox>
</ScrollViewer>
i 命名空间是什么：
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
<UserControl.Resources>
<ControlTemplate x:Key="NoScroll">
<ItemsPresenter></ItemsPresenter>
</ControlTemplate>
</UserControl.Resources>
<ScrollViewer>
<SomeContainerControl>
<.... what ever other controls are inside your ScrollViewer>
<ListBox Template="{StaticResource NoScroll}"></ListBox>
<SomeContainerControl>
</ScrollViewer>
当鼠标进入ScrollViewer时，您确实可以选择捕获鼠标，以便它继续接收所有鼠标事件，直到释放鼠标。但是，如果您希望得到响应，这个选项将要求您将任何后续的鼠标事件委托给包含在ScrollViewer中的控件......以下MouseEnter MouseLeave事件处理程序就足够了。
private void ScrollViewerMouseEnter(object sender, MouseEventArgs e)
{
((ScrollViewer)sender).CaptureMouse();
}
private void ScrollViewerMouseLeave(object sender, MouseEventArgs e)
{
((ScrollViewer)sender).ReleaseMouseCapture();
}
我提供的解决方法都不是最优选，我建议重新考虑你实际想要做什么。如果你在问题中解释你想要实现什么，我相信你会得到更多的建议...
我跟随Amanduh的方法解决了我在WPF中使用多个数据网格和滚动查看器时遇到的同样问题:
public sealed class IgnoreMouseWheelBehavior
{
public static bool GetIgnoreMouseWheel(DataGrid gridItem)
{
return (bool)gridItem.GetValue(IgnoreMouseWheelProperty);
}
public static void SetIgnoreMouseWheel(DataGrid gridItem, bool value)
{
gridItem.SetValue(IgnoreMouseWheelProperty, value);
}
public static readonly DependencyProperty IgnoreMouseWheelProperty =
DependencyProperty.RegisterAttached("IgnoreMouseWheel", typeof(bool),
typeof(IgnoreMouseWheelBehavior), new UIPropertyMetadata(false, OnIgnoreMouseWheelChanged));
static void OnIgnoreMouseWheelChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e)
{
var item = depObj as DataGrid;
if (item == null)
return;
if (e.NewValue is bool == false)
return;
if ((bool)e.NewValue)
item.PreviewMouseWheel += OnPreviewMouseWheel;
else
item.PreviewMouseWheel -= OnPreviewMouseWheel;
}
static void OnPreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
e.Handled = true;
var e2 = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta)
{RoutedEvent = UIElement.MouseWheelEvent};
var gv = sender as DataGrid;
if (gv != null) gv.RaiseEvent(e2);
}
}
DataGrid类型替换为UIElement。我还建议将其命名为“PassthroughMouseWheel”，因为这就是它所做的。特别是它不会吞噬（最终忽略）滚轮事件。另外，这是一个附加属性，而不是行为。在这里，类名是具有误导性的。 - ygoe正如Simon所说，标准ListBox模板中的ScrollViewer捕获了该事件。要绕过它，您可以提供自己的模板。
<ControlTemplate x:Key="NoWheelScrollListBoxTemplate" TargetType="ListBox">
<Border BorderThickness="{TemplateBinding Border.BorderThickness}" Padding="1,1,1,1" BorderBrush="{TemplateBinding Border.BorderBrush}" Background="{TemplateBinding Panel.Background}" Name="Bd" SnapsToDevicePixels="True">
<!-- This is the new control -->
<l:NoWheelScrollViewer Padding="{TemplateBinding Control.Padding}" Focusable="False">
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" />
</l:NoWheelScrollViewer>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="UIElement.IsEnabled" Value="False">
<Setter TargetName="Bd" Property="Panel.Background" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" />
</Trigger>
<Trigger Property="ItemsControl.IsGrouping" Value="True">
<Setter Property="ScrollViewer.CanContentScroll" Value="False" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
而 NoWheelScrollViewer 的实现非常简单。
public class NoWheelScrollViewer : ScrollViewer
{
protected override void OnMouseWheel(MouseWheelEventArgs e)
{
// Do nothing
}
}
然后，每当您希望列表框不处理鼠标滚轮时。
<ListBox Template="{StaticResource NoWheelScrollListBoxTemplate}">
<ListView.Template>
<ControlTemplate>
<ItemsPresenter />
</ControlTemplate>
</ListView.Template>
我试图将Simon Fox的答案应用于DataGrid。我发现模板隐藏了我的标题，并且我从C#中没有得到mouseLeave事件。最终，这是对我有效的：
private void DataGrid_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
((DataGrid)sender).CaptureMouse();
}
private void DataGrid_MouseWheel(object sender, MouseWheelEventArgs e)
{
((DataGrid)sender).ReleaseMouseCapture();
}
public sealed class IgnoreMouseWheelBehavior : Behavior<UIElement>
{
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.PreviewMouseWheel += AssociatedObject_PreviewMouseWheel;
}
protected override void OnDetaching()
{
AssociatedObject.PreviewMouseWheel -= AssociatedObject_PreviewMouseWheel;
base.OnDetaching();
}
static void AssociatedObject_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
if (!(sender is DependencyObject))
{
return;
}
DependencyObject parent = VisualTreeHelper.GetParent((DependencyObject) sender);
if (!(parent is UIElement))
{
return;
}
((UIElement) parent).RaiseEvent(
new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta) { RoutedEvent = UIElement.MouseWheelEvent });
e.Handled = true;
}
}
你必须从ScrollViewer监听PreviewMouseWheel（它有效），而不是从listbox。
Microsoft.Xaml.Behaviors.Wpf) 获取这些内容。不过，我个人没有设置验证。 - Amanduh