SSCCE

gistfile1.txt

1. create a new wpf project called ContentControlDataTemplate
2. open MainWindow.xaml
3. Remove all text, paste the following

<Window x:Class="ContentControlDataTemplate.MainWindow"
        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:ContentControlDataTemplate"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        xmlns:t="clr-namespace:ContentControlDataTemplate"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <DataTemplate DataType="{x:Type t:Foo}">
            <StackPanel>
                <Label>It worked</Label>
                <TextBlock Text="{Binding Text}"/>
            </StackPanel>
        </DataTemplate>
    </Window.Resources>
    <ContentControl Content="{Binding}"/>
</Window>

4. open MainWindow.xaml.cs
5. remove all text, paste the following

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace ContentControlDataTemplate
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new Foo { Text = "lol" };
        }
    }

    public class Foo
    {
        public string Text { get; set; }
    }
}

6. Run