ContextMenu事件处理程序中的ListBox.SelectedIndex [英] ListBox.SelectedIndex in ContextMenu event handler

问题描述

我有一个带有上下文菜单的列表框.如何在ContextMenuItem单击事件处理程序中获取SelectedIndex(SelectedItem)属性的值?当前在事件Edit_Click和Delete_CLick中，CarsList.SelectedIndex的值始终为-1.

I have a listbox with context menu. How can I get value of SelectedIndex (SelectedItem) property in ContextMenuItem click event handler? Currently in events Edit_Click and Delete_CLick a value of CarsList.SelectedIndex always is -1.

在XAML中，这是我的列表框:

Here my ListBox in XAML:

           <ListBox Name="CarsList" Style="{StaticResource ListBoxStyle}" Margin="26,0,26,0" Height="380" >
                <toolkit:ContextMenuService.ContextMenu>
                    <toolkit:ContextMenu Name="ContextMenu" >
                        <toolkit:MenuItem Name="Edit" Header="Edit" Click="Edit_Click"/>
                        <toolkit:MenuItem Name="Delete"  Header="Delete" Click="Delete_Click"/>
                    </toolkit:ContextMenu>
                </toolkit:ContextMenuService.ContextMenu>
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel>
                            <TextBlock Text="{Binding CarName}" TextTrimming="WordEllipsis" Foreground="Black" FontSize="24" Width="428"/>
                            <TextBlock Text="{Binding VIN}" TextWrapping="Wrap" Foreground="Gray" FontSize="20" Width="428"/>
                            <TextBlock Text="{Binding Date}" TextWrapping="Wrap" Foreground="Gray" FontSize="20" Width="428"/>
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

谢谢.

推荐答案

首先，您已将Context Menu分配给ListBox控件，而不是每个项目.因此，将<toolkit:ContextMenuService.ContextMenu>块移至StackPanel.

First of all you have assigned Context Menu to ListBox control, not an each item. So, move <toolkit:ContextMenuService.ContextMenu> block to StackPanel instead.

有几种获取元素的方法，它们是在上下文菜单中单击的:

There are several ways to get element, on which context menu click was performed:

在Click处理程序中，您具有sender对象(我想是MenuItem)

In Click handler you have sender object (it is MenuItem, I guess)

将其投射到MenuItem并查看它的DataContext.这将是您绑定到列表的集合项.因此，您可以通过以下方式找到索引:

Cast it to MenuItem and look to DataContext of it. It will be item of collection you binded to a list. So, you can find index by:

int selectedIndex = YourListBoxItemCollection.IndexOf((sender as MenuItem).DataContext)

，其中YourListBoxItemCollection是您分配给CarsList.ItemsSource

这篇关于ContextMenu事件处理程序中的ListBox.SelectedIndex的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！