WPF Bound ListView Double Click event - wpf

Question

I'm new to WPF so please forgive any of the below that doesn't make sense...
I've set up a view model, which is bound to a WPF List view data template. The source objects (belonging to a class called BrowserItem) are in an ObservableCollection, and I use a CollectionViewSource which diplays them in the ListView - after several headaches this works really well.
I thought the simplest part would be the handling when a user double clicks on something, but I was wrong.
The Event attached to the ListView returns the TextBlock control rather than the BrowserItem source object that was clicked on.
Can anyone point me to a simple way of obtaining the original item (BrowserItem) when the control is clicked on - I've seen several ways of doing this, but they all seem very complex to my simple mind.
A simple example would be great.
This is the XAML for the list view if its of use:
<ListView Name="ViewList"
ItemsSource="{Binding GroupItems}">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Expander>
<Expander.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Children.Count}"
Value="0">
<Setter Property="Expander.Visibility"
Value="Collapsed" />
</DataTrigger>
</Style.Triggers>
</Style>
</Expander.Style>
<ListBox ItemsSource="{Binding Children}" />
</Expander>
<TextBlock Text="{Binding Name}">
<TextBlock.Style>
<Style TargetType="{x:Type TextBlock}">
<Style.Triggers>
<DataTrigger Binding="{Binding Active}"
Value="true">
<Setter Property="Background"
Value="YellowGreen" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Expander>
<Expander.Header>
<TextBlock Text="{Binding Name}" />
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListView.GroupStyle>
</ListView>
Thanks.

Answer 1

You can use EventSetter to add MouseDoubleClick event to listview like below:
<ListView ItemsSource="{Binding Source}" SelectedItem="{Binding SelectedModel, Mode=TwoWay}">
<!--<Behaviors:Interaction.Triggers>
<Behaviors:EventTrigger EventName="MouseDoubleClick">
<Behaviors:InvokeCommandAction Command="{Binding DataContext.Command, RelativeSource={RelativeSource AncestorType={x:Type ListView}}}" />
</Behaviors:EventTrigger>
</Behaviors:Interaction.Triggers>-->
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<EventSetter Event="MouseDoubleClick" Handler="ListViewItem_MouseDoubleClick" />
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate DataType="{x:Type local:Model}">
<TextBlock Text="{Binding Age}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
In this way you just handle it in code behand , not in ViewModel.
If you want handle it in viewmodel, you need one class like this:
public class EventToCommand
{
public static string GetEventName(DependencyObject obj)
{
return (string)obj.GetValue(EventNameProperty);
}
public static void SetEventName(DependencyObject obj, string value)
{
obj.SetValue(EventNameProperty, value);
}
public static readonly DependencyProperty EventNameProperty =
DependencyProperty.RegisterAttached("EventName", typeof(string), typeof(EventToCommand), new PropertyMetadata("", OnEventNameChanged));
public static void OnEventNameChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
}
public static ICommand GetCommand(DependencyObject obj)
{
return (ICommand)obj.GetValue(CommandProperty);
}
public static void SetCommand(DependencyObject obj, ICommand value)
{
obj.SetValue(CommandProperty, value);
}
public static readonly DependencyProperty CommandProperty =
DependencyProperty.RegisterAttached("Command", typeof(ICommand), typeof(EventToCommand), new PropertyMetadata(OnCommandChanged));
public static void OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var element = d as FrameworkElement;
EventInfo eventInfo = d.GetType().GetEvent(GetEventName(d));
var eventHandlerMethodInfo = typeof(EventToCommand).GetMethod("Invoke", BindingFlags.Static | BindingFlags.Public);
eventInfo.AddEventHandler(d, Delegate.CreateDelegate(eventInfo.EventHandlerType, eventHandlerMethodInfo));
}
public static void Invoke(object sender,EventArgs e)
{
var command = GetCommand(sender as FrameworkElement);
command.Execute(e);
}
}
And use class EventToCommand like this:
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="local:EventToCommand.EventName" Value="MouseDoubleClick" />
<Setter Property="local:EventToCommand.Command" Value="{Binding DataContext.Command, RelativeSource={RelativeSource AncestorType={x:Type ListView}}}" />
</Style>
</ListView.ItemContainerStyle>