public static class Extensions
{
    public static void Print(this FrameworkElement element, string Document, HorizontalAlignment HorizontalAlignment, VerticalAlignment VerticalAlignment, Thickness PageMargin, bool PrintLandscape, bool ShrinkToFit, Action OnPrintComplete)
    {
        Print(new List<FrameworkElement>() { element }, Document, HorizontalAlignment, VerticalAlignment, PageMargin, PrintLandscape, ShrinkToFit, OnPrintComplete);
    }

    public static void Print(this UIElementCollection elements, string Document, HorizontalAlignment HorizontalAlignment, VerticalAlignment VerticalAlignment, Thickness PageMargin, bool PrintLandscape, bool ShrinkToFit, Action OnPrintComplete)
    {
        Print(elements.ToList(), Document, HorizontalAlignment, VerticalAlignment, PageMargin, PrintLandscape, ShrinkToFit, OnPrintComplete);
    }

    public static void Print<T>(this List<T> elements, string Document, HorizontalAlignment HorizontalAlignment, VerticalAlignment VerticalAlignment, Thickness PageMargin, bool PrintLandscape, bool ShrinkToFit, Action OnPrintComplete)
    {
        PrintDocument printDocument = new PrintDocument();
        PageMargin = PageMargin == null ? new Thickness(10) : PageMargin;
        Document = (string.IsNullOrEmpty(Document)) ? "Print Document" : Document;
        int currentItemIndex = 0;
        printDocument.PrintPage += delegate(object sender, PrintPageEventArgs evt)
        {
            if (!typeof(FrameworkElement).IsAssignableFrom(elements[currentItemIndex].GetType()))
            {
                throw new Exception("Element must be an object inheriting from FrameworkElement");
            }

            FrameworkElement element = elements[currentItemIndex] as FrameworkElement;

            if (element.Parent == null || element.ActualWidth == double.NaN || element.ActualHeight == double.NaN)
            {
                throw new Exception("Element must be rendered, and must have a parent in order to print.");
            }
                
            TransformGroup transformGroup = new TransformGroup();

            //First move to middle of page...
            transformGroup.Children.Add(new TranslateTransform() { X = (evt.PrintableArea.Width - element.ActualWidth) / 2, Y = (evt.PrintableArea.Height - element.ActualHeight) / 2 });
            double scale = 1;
            if (PrintLandscape)
            {
                //Then, rotate around the center
                transformGroup.Children.Add(new RotateTransform() { Angle = 90, CenterX = evt.PrintableArea.Width / 2, CenterY = evt.PrintableArea.Height / 2 });

                if (ShrinkToFit)
                {
                    if ((element.ActualWidth + PageMargin.Left + PageMargin.Right) > evt.PrintableArea.Height)
                    {
                        scale = Math.Round(evt.PrintableArea.Height / (element.ActualWidth + PageMargin.Left + PageMargin.Right), 2);
                    }
                    if ((element.ActualHeight + PageMargin.Top + PageMargin.Bottom) > evt.PrintableArea.Width)
                    {
                        double scale2 = Math.Round(evt.PrintableArea.Width / (element.ActualHeight + PageMargin.Top + PageMargin.Bottom), 2);
                        scale = (scale2 < scale) ? scale2 : scale;
                    }
                }
            }
            else if (ShrinkToFit)
            {
                //Scale down to fit the page + margin
                    
                if ((element.ActualWidth + PageMargin.Left + PageMargin.Right) > evt.PrintableArea.Width)
                {
                    scale = Math.Round(evt.PrintableArea.Width / (element.ActualWidth + PageMargin.Left + PageMargin.Right), 2);
                }
                if ((element.ActualHeight + PageMargin.Top + PageMargin.Bottom) > evt.PrintableArea.Height)
                {
                    double scale2 = Math.Round(evt.PrintableArea.Height / (element.ActualHeight + PageMargin.Top + PageMargin.Bottom), 2);
                    scale = (scale2 < scale) ? scale2 : scale;
                }
            }

            //Scale down to fit the page + margin
            if (scale != 1)
            {
                transformGroup.Children.Add(new ScaleTransform() { ScaleX = scale, ScaleY = scale, CenterX = evt.PrintableArea.Width / 2, CenterY = evt.PrintableArea.Height / 2 });
            }

            if (VerticalAlignment == VerticalAlignment.Top)
            {
                //Now move to Top
                if (PrintLandscape)
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = PageMargin.Top - (evt.PrintableArea.Height - (element.ActualWidth * scale)) / 2 });
                }
                else
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = PageMargin.Top - (evt.PrintableArea.Height - (element.ActualHeight * scale)) / 2 });
                }
            }
            else if (VerticalAlignment == VerticalAlignment.Bottom)
            {
                //Now move to Bottom
                if (PrintLandscape)
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = ((evt.PrintableArea.Height - (element.ActualWidth * scale)) / 2) - PageMargin.Bottom });
                }
                else
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = ((evt.PrintableArea.Height - (element.ActualHeight * scale)) / 2) - PageMargin.Bottom });
                }
            }

            if (HorizontalAlignment == HorizontalAlignment.Left)
            {
                //Now move to Left
                if (PrintLandscape)
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = PageMargin.Left - (evt.PrintableArea.Width - (element.ActualHeight * scale)) / 2, Y = 0 });
                }
                else
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = PageMargin.Left - (evt.PrintableArea.Width - (element.ActualWidth * scale)) / 2, Y = 0 });
                }
            }
            else if (HorizontalAlignment == HorizontalAlignment.Right)
            {
                //Now move to Right
                if (PrintLandscape)
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = ((evt.PrintableArea.Width - (element.ActualHeight * scale)) / 2) - PageMargin.Right, Y = 0 });
                }
                else
                {
                    transformGroup.Children.Add(new TranslateTransform() { X = ((evt.PrintableArea.Width - (element.ActualWidth * scale)) / 2) - PageMargin.Right, Y = 0 });
                }
            }

            evt.PageVisual = element;
            evt.PageVisual.RenderTransform = transformGroup;
                
            //Increment to next item,
            currentItemIndex++;
                
            //If the currentItemIndex is less than the number of elements, keep printing
            evt.HasMorePages = currentItemIndex < elements.Count;
        };

        printDocument.EndPrint += delegate(object sender, EndPrintEventArgs evt)
        {
            foreach (var item in elements)
            {
                FrameworkElement element = item as FrameworkElement;
                //Reset everything...
                TransformGroup transformGroup = new TransformGroup();
                transformGroup.Children.Add(new ScaleTransform() { ScaleX = 1, ScaleY = 1 });
                transformGroup.Children.Add(new RotateTransform() { Angle = 0 });
                transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = 0 });
                element.RenderTransform = transformGroup;
            }

            //Callback to complete
            if (OnPrintComplete != null)
            {
                OnPrintComplete();
            }
        };

        printDocument.Print(Document);
    }
}

http://www.codeproject.com/KB/silverlight/SilverlightEasyPrint.aspx

The following extension method allows you to call Print() on any FrameworkElement, UIElement or group of elements, and print with a variety of settings such as landscape mode, shrink to fit, page centering, and more

Simplified and Consistent Printing in Silverlight - with Page Margins, Shrink to Fit, and Landscape printing

printing, c#

C#