Dragging a WPF user control

Question

I created a movable UserControl

Answer 1

Based upon information in @Mediator answer. I have came up and edited to prevent the control from going out of bounds.

private TranslateTransform transform = new TranslateTransform();
    private void root_MouseMove(object sender, MouseEventArgs e)
    {
        if (isInDrag)
        {
            var element = sender as FrameworkElement;
            currentPoint = e.GetPosition(null);

            transform.X += currentPoint.X - anchorPoint.X;
            transform.Y += (currentPoint.Y - anchorPoint.Y);
            if (currentPoint.X < Application.Current.MainWindow.RenderSize.Width && currentPoint.Y < Application.Current.MainWindow.RenderSize.Height
                && currentPoint.X > 0 && currentPoint.Y > 0 )
            {
                this.RenderTransform = transform;
                anchorPoint = currentPoint;
            }
            else
            {
                transform = new TranslateTransform();
                this.RenderTransform = transform;
            }
        }
    }

But binding errors are their in output window in VS.

It looks like this is an issue in WPF, but one that Microsoft won't fix.

For more info here:

https://connect.microsoft.com/VisualStudio/feedback/details/1423399/system-windows-data-error-4-when-using-relativesource-findancestor-inside-a-translatetransform-inside-a-style