Here is my Xaml for the ListView
<ListView x:Name="duplicateVarsInCompXMLListView" ItemsSource="{Binding}" HorizontalAlignment="Left" VerticalAlignment="Top" Width="306">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<TextBlock Text="ComponentID: " FontWeight="Bold" Foreground="Brown" />
<TextBlock Text="{Binding Name}"/>
</StackPanel>
<ItemsControl ItemsSource="{Binding Parameters}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Variable Name: " Foreground="Green"/>
<TextBlock Text="{Binding Name}"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Variable Value: " Foreground="Blue"/>
<TextBlock Text="{Binding Value}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Code-behind
private ObservableCollection<Component> mastercomponentcollection;
mastercomponentcollection = //code to populate the collection
duplicateVarsInCompXMLListView.DataContext = this.mastercomponentcollection;
Classes Involved
public class Component
{
private ObservableCollection<ComponentParameter> parameters = new ObservableCollection<ComponentParameter>();
public string Name
{
get;
set;
}
public ObservableCollection<ComponentParameter> Parameters
{
get{return parameters;}
set{parameters = value;}
}
}
public class ComponentParameter
{
public string Name
{
get;set;
}
public string Value
{
get;set;
}
public bool HasErrors
{
get;
set;
}
public bool IsDuplicate
{
get; set;
}
public bool IsMissing
{
get;set;
}
Here I want to show the bindings only for those collection items where the IsDuplicate is set to true. I believe DataTemplate.Triggers is the way to go but I can't figure out the exact syntax to make it work. Any suggestions?
Here is the ItemContainerStyle for your ItemsControl to hide the items with Duplicate as false.
<ItemsControl ItemsSource="{Binding Parameters}">
<ItemsControl.ItemContainerStyle>
<Style >
<Style.Triggers>
<DataTrigger Binding="{Binding IsDuplicate}" Value="false">
<Setter Property="UIElement.Visibility" Value="Collapsed"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ItemsControl.ItemContainerStyle>
If you want to display two different DataTemplate depending on the IsDuplicate property, you can use DataTemplateSelector.
Create a class derived from DataTemplateSelector that selects the DataTemplate
public class MyTemplateSelector : DataTemplateSelector
{
public DataTemplate FirstTemplate { get; set; }
public DataTemplate SecondTemplate { get; set; }
public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
{
var model = item as ComponentParameter;
if (model.IsDuplicated)
return FirstTemplate;
return SecondTemplate;
}
}
Create it in your resources and define the templates in your xaml:
<local:MyTemplateSelector x:Key="itemTemplateSelector">
<local:MyTemplateSelector.FirstTemplate>
<DataTemplate>
<StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Variable Name: " Foreground="Green"/>
<TextBlock Text="{Binding Name}"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Variable Value: " Foreground="Blue"/>
<TextBlock Text="{Binding Value}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</local:MyTemplateSelector.FirstTemplate>
<local:MyTemplateSelector.SecondTemplate>
<DataTemplate>
<!-- Implementation without bindings goes here -->
</DataTemplate>
</local:MyTemplateSelector.SecondTemplate>
</local:MyTemplateSelector>
And use it in your ListView:
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<TextBlock Text="ComponentID: " FontWeight="Bold" Foreground="Brown" />
<TextBlock Text="{Binding Name}"/>
</StackPanel>
<ItemsControl ItemsSource="{Binding Parameters}" ItemTemplateSelector="{StaticResource itemTemplateSelector}"/>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Related
I want to repeat the Border element inside the outer WrapPanel:
<WrapPanel x:Name="filterWrapper" Orientation="Horizontal">
<Border>
<WrapPanel>
<TextBlock Text="{Binding FilterName}"/>
<TextBlock Text="x"/>
</WrapPanel>
</Border>
</WrapPanel>
This is the depending class:
public class FilterField
{
public String FilterName { get; set; }
}
I have a collection of FilterField objects, which should result in:
<WrapPanel x:Name="filterWrapper" Orientation="Horizontal">
<Border>
<WrapPanel>
<TextBlock Text="Test_1"/>
<TextBlock Text="x"/>
</WrapPanel>
</Border>
<Border>
<WrapPanel>
<TextBlock Text="Test_2"/>
<TextBlock Text="x"/>
</WrapPanel>
</Border>
<Border>
<WrapPanel>
<TextBlock Text="Test_3"/>
<TextBlock Text="x"/>
</WrapPanel>
</Border>
</WrapPanel>
How can I achieve this?
You can use the ItemsControl to display a collection of items with a specific template in a specific Panel:
<ItemsControl ItemsSource="{Binding Items}">
<!-- Place all items in a WrapPanel -->
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel x:Name="filterWrapper" Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<!-- Define the look of each item -->
<ItemsControl.ItemTemplate>
<DataTemplate DataType="{x:Type wpfapp1:FilterField}">
<Border>
<WrapPanel>
<TextBlock Text="{Binding FilterName}"/>
<TextBlock Text="x"/>
</WrapPanel>
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
The DataTemplate you define in ItemsControl.ItemTemplate gets applied to all items in the source collection, and each item gets added in the ItemsControl.ItemsPanel that you define, here a WrapPanel.
This is assuming you have a a collection Items of type List<FilterField> in your view model, like this:
public partial class MainWindow : Window {
public MainWindow() {
InitializeComponent();
DataContext = new MyViewModel();
}
}
public class MyViewModel {
public List<FilterField> Items { get; set; } = new List<FilterField> {
new FilterField() { FilterName = "Test_1"},
new FilterField() { FilterName = "Test_2"},
new FilterField() { FilterName = "Test_3"},
};
}
public class FilterField {
public string FilterName { get; set; }
}
I'm building a UWP Application and I need to divide a DataGrid in four equal parts like this:
But nothing worked so far to set the color of cells. Is there any way to do this Programatically in C#?
EDIT:
After a lot of research, I ended developing from scratch using Grid, a bunch of Labels + Borders and a virtual TextBox. The final result was pretty good actually:
There's an easy way to get your requirement. You just need to define the DataTemplate for DataGridTemplateColumn.CellTemplate and bind the background to some one property in your custom class.
Please see my following simple code sample:
<controls:DataGrid
AutoGenerateColumns="False"
ItemsSource="{Binding tests}" GridLinesVisibility="All">
<controls:DataGrid.Columns>
<!-- Name Column -->
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color1}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color1}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color1}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color2}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color2}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
<controls:DataGridTemplateColumn Header="Name">
<controls:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Background="{Binding Color2}">
<TextBlock
Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>
</controls:DataGrid.Columns>
</controls:DataGrid>
public sealed partial class MainPage : Page
{
public ObservableCollection<Test> tests { get; set; }
public MainPage()
{
this.InitializeComponent();
tests = new ObservableCollection<Test>();
for (int i = 0; i < 15; i++)
{
if (i < 7)
{
tests.Add(new Test() { Name = "Name " + i, Color1 = new SolidColorBrush(Colors.Yellow), Color2 = new SolidColorBrush(Colors.Red) });
}
else
{
tests.Add(new Test() { Name = "Name " + i, Color1 = new SolidColorBrush(Colors.Green), Color2 = new SolidColorBrush(Colors.LightBlue) });
}
}
this.DataContext = this;
}
}
public class Test
{
public string Name { get; set; }
public SolidColorBrush Color1 { get; set; }
public SolidColorBrush Color2 { get; set; }
}
I am trying to apply the datatemplate only to type Genre. But it also gets applied to List<string> after Search_Click. How do I make the ListBox apply DataTemplate only to Genre data?
<DataTemplate x:Key="genreTemplate" DataType="{x:Type local:Genre}">
<Border BorderBrush="Green" BorderThickness="2">
<StackPanel Margin="4">
<TextBlock
FontSize="20"
Foreground="Red"
Text="{Binding Name}"
TextAlignment="Center" />
<TextBlock
FontSize="16"
Text="{Binding Count}"
TextAlignment="Right" />
</StackPanel>
</Border>
</DataTemplate>
Code-behind:
public class Genre
{
public string Name { get; set; }
public int Count { get; set; }
public double Size { get; set; }
public string Drive { get; set; }
}
private void Search_Click(object sender, RoutedEventArgs e)
{
var path = Constants.allMoviesPath;
var ext = new List<string> { #".txt", #".ini", #".exe", #".mob", #".srt", #".ass" };
lstBox.ItemsSource = Directory.GetFiles(path, "*" + SearchString + "*", SearchOption.AllDirectories)
.Where(f => !ext.Contains(System.IO.Path.GetExtension(f)))
.Select(f => System.IO.Path.GetFileNameWithoutExtension(f))
.ToList();
}
private void btnStats_Click(object sender, RoutedEventArgs e)
{
lstBox.ItemsSource = FileLists.MoviesCountSizeStats();
}
return type of MoviesCountSizeStats() is List<Genre>
<ListBox
x:Name="lstBox"
Background="CadetBlue"
FontFamily="Consolas"
FontSize="14"
FontWeight="DemiBold"
ItemContainerStyle="{DynamicResource _ListBoxItemStyle}"
ItemTemplate="{StaticResource genreTemplate}"
MouseDoubleClick="lstBox_MouseDoubleClick" />
Instead of applying the template to all items in the list box, as you are doing now, add the template as a resource to the ListBox.Resources (or other suitable resource dictionary), with an implicit key (i.e. implied by the TargetType), and let the template be selected automatically for the item type:
<ListBox
x:Name="lstBox"
Background="CadetBlue"
FontFamily="Consolas"
FontSize="14"
FontWeight="DemiBold"
ItemContainerStyle="{DynamicResource _ListBoxItemStyle}"
MouseDoubleClick="lstBox_MouseDoubleClick">
<ListBox.Resources>
<DataTemplate DataType="{x:Type local:Genre}">
<Border BorderBrush="Green" BorderThickness="2">
<StackPanel Margin="4">
<TextBlock
FontSize="20"
Foreground="Red"
Text="{Binding Name}"
TextAlignment="Center" />
<TextBlock
FontSize="16"
Text="{Binding Count}"
TextAlignment="Right" />
</StackPanel>
</Border>
</DataTemplate>
</ListBox.Resources>
</ListBox>
You can add other templates as necessary for the other data types that might appear in the list box.
In my application I have a window which contain a ListBox, and controls that should show different properties of its currently selected item. Those controls are:
TextBox that should show 'Name' property.
TextBox that should show 'DataFile` property.
DataGrid that should show 'TItems property, which is an ObservableCollection.
I tried to bind SelectedItem to an object, and then bind different properties of that object to the controls mentioned above, with no success.
The window:
My View:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:ReportMaker"
xmlns:ViewModel="clr-namespace:ReportMaker.ViewModel" x:Class="ReportMaker.MainWindow"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<ViewModel:MainViewModel/>
</Window.DataContext>
<Grid>
<Button x:Name="button" Content="Create" HorizontalAlignment="Right" Margin="0,0,10,10" VerticalAlignment="Bottom" Width="75"/>
<ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="10,0,0,10" VerticalAlignment="Bottom" Width="120"/>
<ListBox x:Name="listBox" HorizontalAlignment="Left" Margin="10,10,0,36.667" Width="119" ItemsSource="{Binding ReportItems}" >
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<StackPanel HorizontalAlignment="Left" Height="274" Margin="134,10,0,0" VerticalAlignment="Top" Width="375" DataContext="{Binding SelectedReportItem}">
<StackPanel.Resources>
<Style x:Key="ControlBaseStyle" TargetType="{x:Type Control}">
<Setter Property="Margin" Value="0, 10, 0, 0" />
</Style>
</StackPanel.Resources>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Name:"/>
<TextBox Width="150" Text="{Binding Name}"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Data File:"/>
<TextBox Width="150" Text="{Binding ID}"/>
</StackPanel>
<DataGrid Height="190" VerticalAlignment="Bottom" ItemsSource="{Binding TItems}"/>
</StackPanel>
<Button x:Name="button_Copy" Content="Save" HorizontalAlignment="Right" Margin="0,0,92,10" VerticalAlignment="Bottom" Width="75"/>
</Grid>
</Window>
My ViewModel:
public class MainViewModel
{
public ObservableCollection<ReportItem> ReportItems { get; set; }
public object SelectedReportItem { get; set; }
public MainViewModel()
{
ReportItems = new ObservableCollection<ReportItem>();
ReportItems.Add(Example);
}
public ReportItem Example = new TextReportItem() { Name = "John", DataFile = "try.txt"};
}
ReportItem:
public class ReportItem
{
public int Id { get; set; }
public string Name { get; set; }
public string DataFile { get; set; }
}
TextReportItem:
public class TextReportItem : ReportItem
{
public ObservableCollection<TextParcel> TItems { get; set; }
}
public class TextParcel
{
char Delimiter { get; set; }
string LineExp { get; set; }
string Result { get; set; }
string IgnoreLine { get; set; }
int DesiredResultIndexInLine { get; set; }
}
EDIT: as I use MVVM, I prefer to use only XAML in the View, with no code behind.
EDIT 2:
Thanks to S.Akbari I succeeded to view the desired properties in the TextBox controls, with the following code:
<StackPanel Orientation="Horizontal">
<TextBlock Text="Name:"/>
<TextBox Width="150" Text="{Binding ElementName=listBox, Path=SelectedItem.Name}"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Data File:"/>
<TextBox Width="150" Text="{Binding ElementName=listBox, Path=SelectedItem.DataFile}"/>
</StackPanel>
But when the same logic is applied to my DataGrid, it fails for some reason:
<DataGrid Height="190" VerticalAlignment="Bottom" ItemsSource="{Binding ElementName=listBox, Path=SelectedItem.TItmes}" />
I also tried:
<DataGrid Height="190" VerticalAlignment="Bottom" DataContext="{Binding ElementName=listBox, Path=SelectedItem}" ItemsSource="{Binding TItems}"/>
And also:
<DataGrid Height="190" VerticalAlignment="Bottom" DataContext="{Binding ElementName=listBox, Path=SelectedItem}">
<DataTemplate>
<TextBlock Text="{Binding TItems}" />
</DataTemplate>
</DataGrid>
if you use MVVM your view model should raise property changed events
You should implement INotifyPropertyChanged
and change the selected item to be a full property
see :How to: Implement Property Change Notification
I'm trying to display this hierarchial structure:
public interface IProgressIndicator
{
CancellationToken CancellationToken { get; }
string Name { get; set; }
}
public interface IPercentageProgressIndicator : IProgressIndicator
{
int ProgressPercentage { get; set; }
}
public interface ICountProgressIndicator : IProgressIndicator
{
int ProgressPercentage { get; }
int CurValue { get; set; }
int MaxValue { get; set; }
}
public interface ICompositeProgressIndicator : ICountProgressIndicator
{
ObservableCollection<IProgressIndicator> SubProgressItems { get; }
void MarkAsComplete(IProgressIndicator progress);
IPercentageProgressIndicator CreatePercentageIndicator();
ICountProgressIndicator CreateCountIndicator();
ICompositeProgressIndicator CreateCompositeIndicator();
}
The view shouldn't assume the hierarchial structure is in place; i.e. a regular IProgressIndicator should be displayed (using ContentControl) and using DataTemplates display other types.
So, when IProgressIndicator is of ICompositeProgressIndicator, then the root of the whole hierarchy should be a TreeView, with root tree view item displaying information (like ProgressPercentage and Name). Then children should be displayed again as IProgressIndicator and using DataTemplates choose appropriate way to view its data. Nested ICompositeProgressIndicator objects should just add another tree view item (not whole TreeView).
Here's what I came up with. I had to use Complex Hierarchical Data Templates. Also I'm using custom DataTemplateSelector, which is fairly simple:
public class ProgressIndicatorTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var element = (container as FrameworkElement);
if (item is ICompositeProgressIndicator)
return element.FindResource("CompositeProgressIndicatorTemplate") as DataTemplate;
else if (item is ICountProgressIndicator)
return element.FindResource("CountProgressIndicatorTemplate") as DataTemplate;
else if (item is IPercentageProgressIndicator)
return element.FindResource("PercentageProgressIndicatorTemplate") as DataTemplate;
return null;
}
}
Here's XAML:
<StackPanel Grid.Row="2" Margin="5" Orientation="Vertical">
<StackPanel.Resources>
<editorUtil:ProgressIndicatorTemplateSelector x:Key="progressIndicatorTemplateSelector" />
<Converters:ObjectToTypeConverter x:Key="objectTypeConverter" />
<DataTemplate x:Key="CompositeProgressIndicatorTemplateBase">
<StackPanel Orientation="Vertical">
<TextBlock Text="CompositeProgressIndicatorTemplateBase" />
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding SubProgressItems.Count}" />
<TextBlock Text="{Binding Converter={StaticResource objectTypeConverter}}" Margin="5" />
</StackPanel>
</DataTemplate>
<DataTemplate x:Key="CompositeProgressIndicatorTemplate">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Vertical">
<TextBlock Text="CompositeProgressIndicatorTemplateBase" />
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding SubProgressItems.Count}" />
<TextBlock Text="{Binding Converter={StaticResource objectTypeConverter}}" Margin="5" />
</StackPanel>
<TreeView Grid.Row="1" DataContext="{Binding}">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="IsExpanded" Value="true"/>
</Style>
</TreeView.ItemContainerStyle>
<TreeViewItem ItemsSource="{Binding SubProgressItems}" DataContext="{Binding}"
ItemTemplateSelector="{StaticResource progressIndicatorTemplateSelector}" IsExpanded="True">
<TreeViewItem.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<StackPanel.DataContext>
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type coreUtil:ICompositeProgressIndicator}}"
Path="."/>
</StackPanel.DataContext>
<TextBlock Text="CompositeProgressIndicatorTemplate" />
<ContentControl ContentTemplate="{StaticResource CompositeProgressIndicatorTemplateBase}">
<ContentControl.DataContext>
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type coreUtil:ICompositeProgressIndicator}}"
Path="."/>
</ContentControl.DataContext>
</ContentControl>
</StackPanel>
</DataTemplate>
</TreeViewItem.HeaderTemplate>
</TreeViewItem>
</TreeView>
</Grid>
</DataTemplate>
<HierarchicalDataTemplate DataType="{x:Type coreUtil:ICompositeProgressIndicator}" ItemsSource="{Binding Path=SubProgressItems}">
<ContentControl ContentTemplate="{StaticResource CompositeProgressIndicatorTemplateBase}" />
</HierarchicalDataTemplate>
<DataTemplate x:Key="CountProgressIndicatorTemplate" DataType="{x:Type coreUtil:ICountProgressIndicator}">
<Grid>
<ProgressBar Height="20" Value="{Binding ProgressPercentage, Mode=OneWay}" />
<TextBlock Margin="5" HorizontalAlignment="Center" Text="{Binding ProgressPercentage, Converter={StaticResource percentageConverter}, StringFormat=P}" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="PercentageProgressIndicatorTemplate" DataType="{x:Type coreUtil:IPercentageProgressIndicator}">
<Grid>
<ProgressBar Height="20" Value="{Binding ProgressPercentage, Mode=OneWay}" />
<TextBlock Margin="5" HorizontalAlignment="Center" Text="{Binding ProgressPercentage, Converter={StaticResource percentageConverter}, StringFormat=P}" />
</Grid>
</DataTemplate>
</StackPanel.Resources>
<ContentControl Content="{Binding ProgressIndicator}" ContentTemplateSelector="{StaticResource progressIndicatorTemplateSelector}">
</ContentControl>
</StackPanel>
Here's how it looks at the moment:
There's missing DataContext for the root tree view item.