MVVM Light - Event to Command & ListView - SelectedItem

Question

I have looked all over for an answer to this with no luck. I'm using MVVM Light and I have a ListView in one of my views. I would like to find a way to fire a command when the selected item in my ListView is clicked using the 'Event to Command' built into MVVM Light. At this point, I have no clue how to go about doing this. Any help you could give me would be greatly appreciated.

From my GameView.xaml

<ListView ItemsSource="{Binding Adventurers}"
              Name="AdvListView"
              ScrollViewer.CanContentScroll="False"
              Background="Gray"
              BorderBrush="Transparent"
              Grid.Column="1"
              Grid.ColumnSpan="3"
              Grid.Row="2">

        <i:Interaction.Triggers>
            <i:EventTrigger EventName="Click">
                <cmd:EventToCommand Command="{Binding ShowAdvCommand}"
                                    CommandParameter="{Binding SelectedItem,
                                          ElementName=AdvListView}" />
            </i:EventTrigger>
        </i:Interaction.Triggers>

        <ListView.View>
            <GridView>
                <GridViewColumn Width="Auto" Header="Name" DisplayMemberBinding="{Binding Name}" />
                <GridViewColumn Width="Auto" Header="Level" DisplayMemberBinding="{Binding Level}"/>
            </GridView>
        </ListView.View>
    </ListView>

I'm not entirely sure where in the ListView the EventToCommand should go. Also, I understand that this code is completely incorrect.

From GameViewModel.cs

public ICommand ShowAdvCommand { get; private set; }
ShowAdvCommand = new RelayCommand(() => ExecuteShowAdvCommand(), () => true);

private void ExecuteShowAdvCommand()
{
    System.Windows.MessageBox.Show("Firing");
}

try [this](http://stackoverflow.com/questions/5868589/mvvm-light-adding-eventtocommand-in-xaml-without-blend-easiery-way-or-snippet) — Rafal, Jun 04 '13 at 05:51
Perhaps subscribing to the SelectionChanged instead of the Clicked event would work. Please explain what is supposed to wrong about the command code. — Emond, Jun 04 '13 at 05:57
@ErnodeWeerd That worked. If you'd like to propose that as an answer I would gladly accept it. — Jason D, Jun 04 '13 at 06:32

score 2 · Accepted Answer · answered Jun 04 '13 at 06:35

2

In the XAML you are subscribing to the Clicked event. Change to the SelectionChanged event to make sure there is a SelectedItem.

A click on the ListView will not always select an item.

answered Jun 04 '13 at 06:35

Emond

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One last thing, how might I access that selected item in code (the associated viewmodel to be specific)? – Jason D Jun 04 '13 at 06:40
The Command will part of the ViewModel, so `this` will refer to the ViewModel. If you are interested in the SelectedItem, you are passing it as the parameter but you could also add a dependency property to the ViewModel and bind that to the SelectedItem property of the ListView. If you do that you can access the selected item by accessing the dependency property. – Emond Jun 04 '13 at 06:45
Everything seems to be in line now. Thanks again for your help. – Jason D Jun 04 '13 at 07:13
Good! No problem, that's what we're here for :) – Emond Jun 04 '13 at 07:24

MVVM Light - Event to Command & ListView - SelectedItem

1 Answers1