as I found a lot of tasks (questions) to my question, I still have no idea how that works.
Even it's a much too complex example or simply the needed namespace was missing. So after one hour of research, my question...

How do I intergrate doubleclick-command to my WPF treeview (-items)?

Actually, my tree looks like this:

```
<!-- used Namespace: xmlns:i="http://schemas.microsoft.com/xaml/behaviors" -->
    <TreeView DataContext="{Binding ProjectTree}" ItemsSource="{Binding ProjectNode}" DockPanel.Dock="Left" 
              x:Name="ProjectTree" Margin="0 0 2 0" Grid.Column="0">
        <TreeView.ContextMenu>
            <ContextMenu StaysOpen="True">
                <MenuItem Header="Löschen" Height="20" 
                          Command="{Binding RemoveNodeCommand}"
                          CommandParameter="{Binding ElementName=ProjectTree, Path=SelectedItem}">
                    <MenuItem.Icon>
                        <Image Source="/Icons/32x32/Remove_32x32.png" Width="15" Height="15"/>
                    </MenuItem.Icon> 
                </MenuItem>
            </ContextMenu>
        </TreeView.ContextMenu>

        <i:Interaction.Triggers>
            <i:EventTrigger EventName="SelectedItemChanged">
                <i:InvokeCommandAction Command="{Binding TreeNodeSelectedCommand}" 
                                       CommandParameter="{Binding ElementName=ProjectTree, Path=SelectedItem}"/>
            </i:EventTrigger>
            <i:EventTrigger EventName="MouseDoubleClick">
                <i:InvokeCommandAction Command="{Binding UpdateNodeCommand}" 
                                       CommandParameter="{Binding ElementName=ProjectTree, Path=SelectedItem}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>

        <TreeView.ItemContainerStyle>
            <Style TargetType="{x:Type TreeViewItem}">
                <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}"/>
                <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>
                <Setter Property="FontWeight" Value="Normal"/>
                <Style.Triggers>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter Property="FontWeight" Value="Bold"/>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </TreeView.ItemContainerStyle>

        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Children}">
                <StackPanel Orientation="Horizontal">
                    <Image Margin="3" Source="{Binding ItemType, Converter={x:Static misc:TreeItemImageConverter.Instance }}" Width="20" />
                    <TextBlock VerticalAlignment="Center" Text="{Binding Name}"/>
                </StackPanel>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>

```

I don't really understand how the Interaction.Triggers work but should they be the right way?

I'm using the ICommand and a relaycommand for my menu- and button-commands. So far, everything fine in my viewmodels.

Sorry if that is a noob question.

**EDIT**
As it wasn't a noob question but a noob typo, `MouseDoubleClick` simply works as `SelectedItemChanged` so my question was unneccessary. (updated code above)