WPF Move controls

MainWindow.xaml

<Window x:Class="WPFTestControlMoveMouse.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:WPFTestControlMoveMouse"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="30" />
            <RowDefinition />
        </Grid.RowDefinitions>

        <Button Grid.Row="0" Click="Button_Click">New</Button>
        <Canvas x:Name="MyCanvas" Grid.Row="1"></Canvas>
    </Grid>
</Window>

MainWindow.xaml.cs

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 WPFTestControlMoveMouse
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            MyCanvas.Children.Add(new VisualBlock());
        }
    }
}

VisualBlock.xaml

<UserControl x:Class="WPFTestControlMoveMouse.VisualBlock"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WPFTestControlMoveMouse"
             mc:Ignorable="d" 
             Width="300" Height="200" MouseDown="UserControl_MouseDown" MouseUp="UserControl_MouseUp" MouseMove="UserControl_MouseMove">
    <Grid>
        <Border BorderBrush="Black" BorderThickness="1" Background="Silver" />
        <TextBlock FontSize="48" HorizontalAlignment="Center" VerticalAlignment="Center">Hi there!!</TextBlock>
    </Grid>
</UserControl>

VisualBlock.xaml.cs

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 WPFTestControlMoveMouse
{
    /// <summary>
    /// Interaction logic for VisualBlock.xaml
    /// </summary>
    public partial class VisualBlock : UserControl
    {
        private Point _positionInBlock;

        public VisualBlock()
        {
            InitializeComponent();
        }

        private void UserControl_MouseDown(object sender, MouseButtonEventArgs e)
        {
            // when the mouse is down, get the position within the current control. (so the control top/left doesn't move to the mouse position)
            _positionInBlock = Mouse.GetPosition(this);

            // capture the mouse (so the mouse move events are still triggered (even when the mouse is not above the control)
            this.CaptureMouse();
        }

        private void UserControl_MouseMove(object sender, MouseEventArgs e)
        {
            // if the mouse is captured. you are moving it. (there is your 'real' boolean)
            if (this.IsMouseCaptured)
            {
                // get the parent container
                var container = VisualTreeHelper.GetParent(this) as UIElement;

                // get the position within the container
                var mousePosition = e.GetPosition(container);

                // move the usercontrol.
                this.RenderTransform = new TranslateTransform(mousePosition.X - _positionInBlock.X, mousePosition.Y - _positionInBlock.Y);
            }
        }

        private void UserControl_MouseUp(object sender, MouseButtonEventArgs e)
        {
            // release this control.
            this.ReleaseMouseCapture();
        }
    }
}