[英]In WPF, how do I select the treeview item under my cursor on right-click?
In WPF, when I right-click on a treeview item I would like it to be Selected/Activated before showing the context menu. 在WPF中,当我右键单击树视图项目时,我希望在显示上下文菜单之前先选择/激活它。
This sounds pretty simple, but the inclusion of a hierachicalDataTemplate complicates things a little. 这听起来很简单,但是包含hierachicalDataTemplate会使事情复杂一些。
I have the following treeview: 我有以下树视图:
<TreeView
x:Name="trv"
ContextMenu="{StaticResource contextMenu}"
ItemTemplate="{StaticResource treeHierarchicalDataTemplate}"
ItemsSource="{Binding Source={StaticResource meetingItems}}" >
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<EventSetter Event="TreeViewItem.PreviewMouseRightButtonDown" Handler="trv_PreviewMouseRightButtonDown"/>
<Setter Property="IsExpanded" Value="True"></Setter>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
And here is my event handler... 这是我的事件处理程序...
private void trv_PreviewMouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
TreeViewItem item = sender as TreeViewItem;
if (item != null)
{
item.Focus();
e.Handled = true;
}
}
Note how I add an EventSetter above. 请注意我如何在上面添加一个EventSetter。 This ALMOST works.
此ALMOST有效。 But it only selects the root-level treeview node (ie the root parent of the node on which I right click).
但是它仅选择根级树视图节点(即,我在其上单击鼠标右键的节点的根父节点)。 This may be because of my hierarchical data template?
这可能是因为我的分层数据模板吗? This template can contain children OF THE SAME TYPE.
该模板可以包含相同类型的子级。
Here is my hierarchical data template... 这是我的分层数据模板...
<HierarchicalDataTemplate x:Key="treeHierarchicalDataTemplate"
ItemsSource="{Binding Path=ChildMeetingItems}">
<HierarchicalDataTemplate.Triggers>
<DataTrigger Binding="{Binding Path=Red}" Value="True">
<Setter TargetName="img" Property="Image.Source" Value="pack://siteoforigin:,,,/images/bookRed.png"></Setter>
</DataTrigger>
</HierarchicalDataTemplate.Triggers>
<StackPanel
x:Name="treeViewItemPanel"
Background="Transparent"
Orientation="Horizontal">
<Image Width="16" Height="16" x:Name="img" Margin="0,0,4,0" Source="pack://siteoforigin:,,,/images/bookGreen.png"></Image>
<TextBlock Foreground="DarkGray" Text="{Binding DisplayIndex}" Margin="0,0,5,0"></TextBlock>
<TextBlock Text="{Binding Summary}"></TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
Any idea on why only the root node instead of child nodes are selected when I right-click? 我为什么右键单击时为什么只选择根节点而不选择子节点?
That's because the ItemContainerStyle is not inherited by the child nodes. 这是因为ItemContainerStyle未被子节点继承。 You need to add the same EventSetter on the ItemContainerStyle o your HierarchicalDataTemplate.
您需要在HierarchicalDataTemplate的ItemContainerStyle上添加相同的EventSetter。
<HierarchicalDataTemplate x:Key="treeHierarchicalDataTemplate"
ItemsSource="{Binding Path=ChildMeetingItems}">
<HierarchicalDataTemplate.Triggers>
<DataTrigger Binding="{Binding Path=Red}" Value="True">
<Setter TargetName="img" Property="Image.Source" Value="pack://siteoforigin:,,,/images/bookRed.png"></Setter>
</DataTrigger>
</HierarchicalDataTemplate.Triggers>
<StackPanel
x:Name="treeViewItemPanel"
Background="Transparent"
Orientation="Horizontal">
<Image Width="16" Height="16" x:Name="img" Margin="0,0,4,0" Source="pack://siteoforigin:,,,/images/bookGreen.png"></Image>
<TextBlock Foreground="DarkGray" Text="{Binding DisplayIndex}" Margin="0,0,5,0"></TextBlock>
<TextBlock Text="{Binding Summary}"></TextBlock>
</StackPanel>
<HierarchicalDataTemplate.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<EventSetter Event="TreeViewItem.PreviewMouseRightButtonDown" Handler="trv_PreviewMouseRightButtonDown"/>
</Style>
</HierarchicalDataTemplate.ItemContainerStyle>
</HierarchicalDataTemplate>
just comment the e.Handler=true
from your event handler. 只需在事件处理程序中注释
e.Handler=true
。
like this: 像这样:
private void trv_PreviewMouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
TreeViewItem item = sender as TreeViewItem;
if (item != null)
{
item.Focus();
// e.Handled = true;
}
}
I had the same problem - couldn't get the proper selected tree item. 我遇到了同样的问题-无法获得正确的选定树项。 And instead of using
PreviewMouseRightButtonDown
event I used same event of a StackPanel
which also stores all needful data: 我没有使用
PreviewMouseRightButtonDown
事件,而是使用了StackPanel
相同事件,该事件还存储了所有需要的数据:
<StackPanel DataContext="{Binding}" MouseLeftButtonDown="StackPanel_MouseLeftButtonDown">
....
</StackPanel>
And the event handler code-behind: 以及事件处理程序的代码背后:
private void StackPanel_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
StackPanel panel = sender as StackPanel;
if(panel==null)return;
MyTreeViewItem myClicked = panel.DataContext as MyTreeViewItem;
if (myClicked == null) return;
...
}
MyTreeViewItem
is my custom type for a data; MyTreeViewItem
是我的数据自定义类型; myClicked
now stores a data associated with the clicked tree item. myClicked
现在存储与单击的树项目关联的数据。 Hope it will help someone like me. 希望它能帮助像我这样的人。
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