How can I set the click effect on a text block and open a new WPF window?

This is the MVVM police!;)

Xaml: Use bindings to ICommand instead of System.Windows.Interactivity and forinstance galasoft mvvm light. I have not tested the code below, I just wrote it in notepad ++ .. Oh, I see one thing here, you do this inside datatemplate and listboxitem ... Your TextBlock will look for the command on LI, not VM, so you need funky binding. Check if it works, but you want your click event to fire on the datacontext vm and not on the list item, so the binding should be slightly modified (leave ... =)) Items in the list are put in ListBoxItems and datacontext sets then what LI should represent, an item in the list.

You might want to change the KeyUp binding below frpm

<command:EventToCommand Command="{Binding KeyUpCommand}" PassEventArgsToCommand="True"/> 

      

        
        
        
      

    

To:

<command:EventToCommand Command="{Binding Path=DataContext.KeyUpCommandCommand, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}}}"  PassEventArgsToCommand="True"/>

      

        
        
        
      

    

To replace UserControl with the name of your control / page / cust ctrl / window.

...
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:command="http://www.galasoft.ch/mvvmlight"
xmlns:local="clr-namespace:YOURNAMSPACE"
...

<UserControl.DataContext>
    <local:ViewModelListStuff/>
</UserControl.DataContext>

<Grid>
    <ItemsControl ItemsSource="{Binding Source={StaticResource cvsRoutes}}">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Expander Header="{Binding Name}" MinHeight="50">
                    <ListBox>                            
                        <i:Interaction.Triggers>
                            <i:EventTrigger EventName="PreviewMouseLeftButtonDown">
                                <command:EventToCommand Command="{Binding PreviewMouseLeftButtonDownCommand}" PassEventArgsToCommand="True"/>
                            </i:EventTrigger>
                        </i:Interaction.Triggers>
                        <TextBlock Text="Something" >
                            <i:Interaction.Triggers>
                                <i:EventTrigger EventName="KeyUp">
                                    <command:EventToCommand Command="{Binding KeyUpCommand}" PassEventArgsToCommand="True"/>
                                </i:EventTrigger>
                            </i:Interaction.Triggers>
                        </TextBlock>
                        <TextBlock Text="Something" />
                        <TextBlock Text="Something" />
                        <TextBlock Text="Something" />
                        <TextBlock Text="Something" />
                    </ListBox>
                </Expander>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ItemsControl>
</Grid>

      

        
        
        
      

    

Now you need a viewmodel, which you set as datacontext. Here's an example with a simple base class (it's helpful to add the ViewModelBase provided by galasoft to add functionality.

base VM class (simplified):

public class SomeBaseClass : INotifyPropertyChanged
{
    // Other common functionality goes here..

    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]// Commment out if your don't have R#
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }
}

      

        
        
        
      

    

VM:

public class ViewModelListStuff : SomeBaseClass
{
    private string name;
    public ICommand PreviewMouseLeftButtonDownCommand { get; set; }
    public ICommand KeyUpCommand { get; set; }

    public String Name
    {
        get { return name; }
        set
        {
            if (value == name) return;
            name = value;
            OnPropertyChanged();
        }
    }

    // I would have exposed your cvsSomething here as a property instead, whatever it is.

    public ViewModelListStuff() 
    {
        InitStuff();
    }

    public void InitStuff()
    {
        PreviewMouseLeftButtonDownCommand = new RelayCommand<MouseButtonEventArgs>(PreviewMouseLeftButtonDown);
        KeyUpCommandnCommand = new RelayCommand<KeyEventArgs>(KeyUp);
    }

    private void KeyUp(KeyEventArgs e)
    {
        // Do your stuff here...
    }

    private void PreviewMouseLeftButtonDown(MouseButtonEventArgs e)
    {
        // Do your stuff heere
    }
}

      

        
        
        
      

    

Hope this helps! Create a breakpoint in the methods that we will call with commands, and we will observe your output and the stacktrace of command methods.

Greetings

Stian