Question

我使用的是ListBoxItem风格的MouseBindings。

<MouseBinding MouseAction="LeftClick" Command="{Binding    
DataContext.ViewWorkingImprovementAssetCommand}" CommandParameter="{Binding}"/>

具体来说，我使用LeftClick命令在视图模型中触发命令。问题是未在ListBox中选择项目，因为鼠标事件未进入列表框。那么有没有办法将事件传递给父控件（ListBox）？

如果我在ListBox上为SelectionChanged使用交互式触发器，我可以使用此功能，但问题是重新单击已选择的项目不会像名称所示那样触发事件。当我的列表中只有一个项目出现问题时。

<i:Interaction.Triggers>
    <i:EventTrigger EventName="SelectionChanged">
         <i:InvokeCommandAction Command="{Binding ViewWorkingImprovementAssetCommand}" 
                                CommandParameter="{Binding ElementName=RemovedImprovementAssetsListBox, Path=SelectedItem}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

有什么想法吗？

Answer 1

显然MouseBinding窃取事件并且不会传递它。我使用我们在解决方案中已经拥有的AttachedBehaviors解决了它。我认为取自http://marlongrech.wordpress.com/2008/12/13/attachedcommandbehavior-v2-aka-acb/

最终代码解决方案

<cmd:CommandBehaviorCollection.Behaviors>
<cmd:BehaviorBinding Event="MouseLeftButtonDown" 
                    Command="{Binding  RelativeSource={RelativeSource FindAncestor,  AncestorType=UserControl, AncestorLevel=1}, Path=DataContext.ViewWorkingImprovementAssetCommand}" 
                    CommandParameter="{Binding}"/>
</cmd:CommandBehaviorCollection.Behaviors>

Answer 2

在ListBox上为PreviewMouseDown添加一个处理程序。

private void myListBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    MyObject entry = null;

    // did user click on a list entry?
    var pos = e.GetPosition(myListBox);
    var elem = myListBox.InputHitTest(pos);
    if (elem is FrameworkElement && (elem as FrameworkElement).DataContext != null)
    {
        ListBoxItem item = myListBox.ItemContainerGenerator.ContainerFromItem((elem as FrameworkElement).DataContext) as ListBoxItem;
        entry = item.DataContext as MyObject;
    }

    // do something with entry

    // if you don't want the event to bubble up, then set e.Handled=true
    // But then you will probably want to set  myListBox.SelectedItem = entry
    e.Handled = true;
}

ListBoxItem窃取ListBox中的鼠标单击

2 个答案: