<ContextMenu x:Key="TreeContextMenuTest" ItemsSource="{Binding ContextMenu}">....

<Style TargetType='{x:Type ListViewItem}'>
    <Setter Property="ContextMenu" Value="{StaticResource TreeContextMenuTest}" />
</Style>

<Setter Property="ContextMenu" Value="{DynamicResource TreeContextMenuTest}" />

<Window x:Class="WpfApplication3.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Grid.Resources>
        <Style TargetType='{x:Type ListViewItem}'>
            <Setter Property="ContextMenu" Value="{StaticResource TreeContextMenuTest}" />
        </Style>
    </Grid.Resources>
    <ListView>
        <ListViewItem>aaa</ListViewItem>
        <ListViewItem>bbb</ListViewItem>
        <ListViewItem>ccc</ListViewItem>
    </ListView>
</Grid>

<Application x:Class="WpfApplication3.App"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         StartupUri="MainWindow.xaml">
<Application.Resources>
    <ContextMenu x:Key="TreeContextMenuTest" ItemsSource="{Binding ContextMenu}"/>

</Application.Resources>

public partial class App : Application
{
    public ObservableCollection<MenuItem> ContextMenu { get; set; }

    public App()
    {
        ContextMenu = new ObservableCollection<MenuItem>();
        var mi = new MenuItem {Name = "Test"};
        ContextMenu.Add(mi);
    }
}