Mvvm Light UWP Index Of Listitem When Button In ListItem Is Pressed

问题

My issue:

I got a ListView which has a ItemTemplate; containing a DataTemplate with some AppBarButtons in it. Now when the user is pressing one of the Buttons in the ListView the ListItem which is containing the button doesn't get highlighted. This Problem also leads to the issue that I don't know how to get the index of the listitem which is containing the button the user clicked.

ListItem:

The code in Mainpage.xaml:

       <ListView.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Vertical">                                 
                                <StackPanel Orientation="Horizontal"> 
                                           <!-- Simplified, Left out other AppBarButtons -->
                                            <AppBarButton Foreground="White" VerticalAlignment="Center" 
                                              Label="Navigate" Icon="Map" >
                                                <interactivity:Interaction.Behaviors>
                                                    <core:EventTriggerBehavior EventName="Tapped">
                                                        <core:InvokeCommandAction Command="{Binding Main.OpenMapCommand, Mode=OneWay, Source={StaticResource Locator}}"></core:InvokeCommandAction>
                                                    </core:EventTriggerBehavior>
                                                </interactivity:Interaction.Behaviors>
                                            </AppBarButton>                                      
                                </StackPanel>
                            </StackPanel>
                        </DataTemplate>
        </ListView.ItemTemplate>

The command:

    public RelayCommand OpenMapCommand
    {
        get
        {
            return _openMapCommand
                       ?? (_openPaneCommand = new RelayCommand(
                           () =>
                           {
                               Debug.WriteLine("Opening map");
                               // Center on New York City
                               var uriNewYork = new Uri(@"bingmaps:?cp=40.726966~-74.006076");

                               // Launch the Windows Maps app
                               var launcherOptions = new Windows.System.LauncherOptions();
                               launcherOptions.TargetApplicationPackageFamilyName = "Microsoft.WindowsMaps_8wekyb3d8bbwe";
                               var success = Windows.System.Launcher.LaunchUriAsync(uriNewYork, launcherOptions);
                           }));
                   }
    }

Whatan answer to this question needs to provide:

How to get the index of the ListItem which is containing the AppBarButton which has been pressed for being used in the relaycommand (be aware the ListItem doesn't get selected when the user is pressing the AppBarButton)

回答1:

The DataContext within the ItemTemplate will be the item that you want to pass as a command parameter, so you should be able to just bind it to CommandParameter:

<core:InvokeCommandAction Command="{Binding Main.OpenMapCommand, Source={StaticResource Locator}}" CommandParameter="{Binding}"/>

_openPaneCommand = new RelayCommand(item =>
{
    ....
});

回答2:

A common scenario is using the Tag property on the button, bound to a value of the ListItem and passing that as Command Parameter

See other StackO answer for details UWP buttons inside Listview items

来源：https://stackoverflow.com/questions/40343526/mvvm-light-uwp-index-of-listitem-when-button-in-listitem-is-pressed

标签

xaml

listview

uwp

mvvm-light