WPF

<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:local='clr-namespace:MyAssembly;assembly=MyAssembly>
    <Button x:Name='btnShowSubgrid' Tag='{Binding ID}' Click='btnShowSubgrid_Click' Margin='4' Width='20'>
      <Button.Content>
        <Image x:Name='imgButtonTemplate' Source='Images/rightBlueArrow.png' />
      </Button.Content>
    </Button>
</DataTemplate>

DataGridTemplateColumn buttonColumn = new DataGridTemplateColumn(); 
 
                    using (StreamReader reader = new StreamReader(Assembly.GetExecutingAssembly().GetManifestResourceStream("MyAssembly.CellTemplates.ButtonCellTemplate.xml"))) 
                    { 
                        String str = reader.ReadToEnd(); 
                        str = str.Replace("(ColumnToBind)", _gridDefinition.SubGrid.Param); 
 
                        buttonColumn.CellTemplate = (DataTemplate)XamlReader.Load(str); 
                    } 
 
                    dgGrid.Columns.Add(buttonColumn);

public MainWindowViewModel()
{
    if (!isServerRunning)
    {
        this.ModalWindow = new LogViewModel("Service is down.");
    }
    else
    {
        this.ModalWindow = new LogViewModel();
    }
}

public MainWindowViewModel(string logMessage)
{
    this.ModalWindow = new LogViewModel(logMessage);
}

public LogViewModel ModalWindow
{
    get
    {
        return _modalWindow;
    }
    set
    {
        _modalWindow = value;

        OnPropertyChanged("ModalWindow");
    }
}

<Grid>
    <vw:LogView Content="{Binding Path=ModalWindow}"/>
</Grid>

protected override void OnStartup(StartupEventArgs e)
{
    base.OnStartup(e);
    MainWindow mainWindow = new MainWindow();
    MainWindowViewModel viewModel = new MainWindowViewModel();
    mainWindow.DataContext = viewModel;
    mainWindow.Show();
}

<UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/LKCommon;component/Styles.xaml" />
            </ResourceDictionary.MergedDictionaries>
            <!-- Converters -->
            <converters:OrientationToAngleConverter x:Key="OrientationToAngleConverter" />
        </ResourceDictionary>
    </UserControl.Resources>