Question

I have a MainWindow that contains a window with a TreeView. The tree view binds to an observable collection that I set in the DataContext.

                    <TreeView ItemsSource="{Binding Trees}"  Name="fileTree" MouseDoubleClick="FileTreeMouseDoubleClick" SelectedValuePath="NodePath">
                        <TreeView.Resources>
                        <HierarchicalDataTemplate DataType="{x:Type local:TreeNodeViewModel}" ItemsSource="{Binding Children}">
                            </HierarchicalDataTemplate>
                        </TreeView.Resources>
                    </TreeView>                        

However, I want to put a separate tree as a child of the MainWindow, which will bind to a different object, how can I do that If I have already used the DataContext property of the MainWindow.xaml?

EDIT: Extension to Question

Now I have:

<TreeView Name="viewTree" ItemsSource="{Binding ViewListTrees, Source=viewListTreeViewModel}">

Where viewListTreeViewModel is a member variable in MainWindow.xaml.cs:

private ViewListTreeViewModel viewListTreeViewModel;

which has the following accessor:

    public ObservableCollection<ViewListTreeNodeViewModel> ViewListTrees
    {
        get { return this.tree; }
    }

and ViewListTreeNodeViewModel has:

    public string NodeName { get; }

    public string NodeImage { get; }

My hierarchical data template now looks like:

                            <HierarchicalDataTemplate DataType="{x:Type local:ViewListTreeNodeViewModel}" ItemsSource="{Binding Children}">
                                <StackPanel>
                                    <Image Source="{Binding NodeImage}" />
                                    <TextBlock Text="{Binding NodeName}"/>
                                </StackPanel>
                            </HierarchicalDataTemplate>

Answer 1

Simply expose two Properties on a class you bind to your Window (rather than binding the collection directly), exposing ObservableCollection properties; Trees and SeperateTree and bind each TreeView accordingly:

<Window>
  <Grid>
    <TreeView ItemsSource="{Binding Trees}">
      ...
    </TreeView>
    <TreeView ItemsSource="{Binding SeperateTree}">
      ...
    </TreeView>
  </Grid>
</Window>