Question

因此我无法在点击事件中找回正确的SelectedIndex。无论我选择什么项目，我都会回来-1

这是我的活动：

private void Delete_Click(object sender, RoutedEventArgs e)
{
    var index = CitiesDisplay.SelectedIndex;
    if(CitiesDisplay.SelectedIndex >= 0)
    { 
        vm.Cities.Remove(vm.Cities[index]);
    }
}

这是我的ListView：

<ListView Name="CitiesDisplay" ItemsSource="{Binding}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Vertical" Holding="ListViewItem_Holding">
                <!-- Begin Flyout menu -->
                <FlyoutBase.AttachedFlyout>
                    <MenuFlyout>
                        <MenuFlyoutItem Text="Delete" Click="Delete_Click"/>
                        <MenuFlyoutItem Text="Navigate To" Click="NavigateTo_Click"/>
                    </MenuFlyout>
                </FlyoutBase.AttachedFlyout>
                <!-- End Flyout Menu -->
                <StackPanel Orientation="Horizontal">
                    <StackPanel Orientation="Vertical">
                        <TextBlock Name="CityName" Text="{Binding Name}" FontSize="20"></TextBlock>
                        <TextBlock Name="MaxTemp" Text="{Binding max}"/>
                        <TextBlock Name="MinTemp" Text="{Binding min}"/>
                        <TextBlock Name="CurrentTemp" Text="{Binding temp}"/>
                    </StackPanel>
                    <Image Name="Logo" Width="50" Height="50" Source="{Binding icon}" HorizontalAlignment="Right" Margin="5"/>
                </StackPanel>
            </StackPanel>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

我真的不明白为什么我无法获得我的SelectedIndex，因为我在之前的项目中做了同样的事情而且它完美无缺。

我也尝试过操纵SelectedItems无济于事。

其他一些细节：我使用Visual Studio 2015 Update 1开发Windows Phone 8.1应用程序（winrt）。

Answer 1

是的，SelectedIndex将始终保持为-1，因为ItemClick Stackpanel＆消耗点击事件的设计约束，SelectionChanged和ItemTemplate事件都不会触发＃39; s Holding事件要解决这个问题，你会

要求将VisualTree遍历到父级 ItemTemplate中
将其内容绑定到您的Binding模型并尝试获取值。

您的XAML将保持不变，您的代码将更改为

private DependencyObject GetDependencyObjectFromVisualTree(DependencyObject startObject, Type type)
        {              
            DependencyObject parent = startObject;
            while (parent != null)
            {
                if (type.IsInstanceOfType(parent))
                    break;
                else
                    parent = VisualTreeHelper.GetParent(parent);
            }
            return parent;
        }


        private void Delete_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
        {
            var selectedItem = GetDependencyObjectFromVisualTree(e.OriginalSource as DependencyObject, typeof(ListViewItem)) as ListViewItem;      
//here you can use it to traverse your vm.Cities list to update it or do anything.
           System.Diagnostics.Debug.WriteLine(((YourModel)selectedItem.Content).Cities);
        }

无法获得有效的ListView.SelectedIndex

1 个答案: