View is not binding correctly to ViewModel - wpf

Question

I cannot get the View to bind correctly to the ViewModel. When it displays, it only shows the string version of the ViewModel.
I have seen: Setting Window.Content to ViewModel - simple data template not working. But the link is no longer available.
I'm trying to use https://msdn.microsoft.com/en-us/magazine/dd419663.aspx, as a template.
MainWindow.xaml
<Window x:Class="DemoApp.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:DemoApp.ViewModel"
xmlns:vw="clr-namespace:DemoApp.View">
<Window.Resources>
<DataTemplate DataType="{x:Type vm:TestViewModel}">
<vw:TestView/>
</DataTemplate>
<DataTemplate x:Key="ClosableTabItemTemplate">
<DockPanel Width="120">
<Button
Command="{Binding Path=CloseCommand}"
Content="X"
Cursor="Hand"
DockPanel.Dock="Right"
VerticalContentAlignment="Bottom"
Width="16" Height="16"/>
<ContentPresenter
Content="{Binding Path=DisplayName}"
VerticalAlignment="Center"/>
</DockPanel>
</DataTemplate>
<DataTemplate x:Key="WorkspacesTemplate">
<TabControl
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding}"
ItemTemplate="{StaticResource ClosableTabItemTemplate}"
Margin="4" />
</DataTemplate>
</Window.Resources>
<DockPanel>
<Border
Grid.Column="2"
Style="{StaticResource MainBorderStyle}">
<HeaderedContentControl
Content="{Binding Path=Workspaces}"
ContentTemplate="{StaticResource WorkspacesTemplate}"
Header="Workspaces"
Style="{StaticResource MainHCCStyle}" />
</Border>
</DockPanel>
</Window>
MainWindowViewModel.cs
// ommitted for clarity. This is directing to the view model correctly. It's the binding between View and ViewModel that is not
TestView.xaml
public class TestViewModel : WorkspaceViewModel, INotifyPropertyChanged,
{
public Model.Test _test;
public string DisplayName {get; set;}
public class TestViewModel(Model.Test t)
{
DisplayName = "Test Display Name";
_model = t;
}
// INofifyPropertyChanged Members removed for clarity
}
Test.cs
public class Test
{
public string FirstName {get; set;}
public string LastName {get; set;}
public static DisplayTest()
{
return new Test();
}
}
Displays:
DemoApp.ViewModel.TestViewModel;
However, when I go to the MainWindow.xaml and actually type in into a DockPanel, it will display correctly...
Thank you!!
UPDATE:
MainWindowViewModel.cs Properties
public ReadOnlyCollection<CommandViewModel> Commands
{
get
{
if (_commands == null)
{
List<CommandViewModel> cmds = this.CreateCommands();
_commands = new ReadOnlyCollection<CommandViewModel>(cmds);
}
return _commands;
}
}
public ObservableCollection<WorkspaceViewModel> Workspaces
{
get
{
if (_workspaces == null)
{
_workspaces = new ObservableCollection<WorkspaceViewModel>();
_workspaces.CollectionChanged += this.OnWorkspacesChanged;
}
return _workspaces;
}
}

Answer 1

In the View there was a Data Context Declared. This was confusing the binding it looks like. Once the Data Context in the View was removed and the MainWindowResourses kept the data context, the view is displayed as it should.