MARKUS



using System;

using System.Collections.Generic;

using System.IO;

using System.Reflection;

using System.Threading;

using System.Windows;

using System.Windows.Markup;

using System.Windows.Media;

using System.Windows.Media.Imaging;

namespace XAMLtoPNG

{

  public enum ScaleTO

  {

    OriginalSize=1,

    TargetSize=2

  }

  /// <summary>

  /// Source: http://blog.galasoft.ch/archive/2008/10/10/converting-and-customizing-xaml-to-png-with-server-side-wpf.aspx

  /// </summary>

  public class XamlToPngConverter

  {

    public void Convert(Stream xamlInput,

      double width, 

      double height,

      double dpiX,

      double dpiY,

      ScaleTO thisScale,

      Stream pngOutput)

    {

      try

      {

        // Round width and height to simplify

        width = Math.Round(width);

        height = Math.Round(height);

        Thread pngCreationThread = new Thread((ThreadStart) delegate()

        {

          FrameworkElement element = null;

          try

          {

            var inputElement = XamlReader.Load(xamlInput) as FrameworkElement;

            var viewbox = new System.Windows.Controls.Viewbox();

            viewbox.Stretch = Stretch.Fill;

            viewbox.Child = inputElement;

            viewbox.Width = width;

            viewbox.Height = height;

            element = viewbox;

          }

          catch (XamlParseException)

          {

          }

          if (element != null)

          {

            Size renderingSize = new Size(width, height);

            element.Measure(renderingSize);

            Rect renderingRectangle = new Rect(renderingSize);

            element.Arrange(renderingRectangle);

            BitmapSource xamlBitmap = RenderToBitmap(element, width, height, dpiX, dpiY, thisScale);

            try

            {

              PngBitmapEncoder enc = new PngBitmapEncoder();

              enc.Frames.Add(BitmapFrame.Create(xamlBitmap));

              enc.Save(pngOutput);

            }

            catch (ObjectDisposedException)

            {

              // IF the operation lasted too long, the object might be disposed already

            }

          }

        });

        pngCreationThread.IsBackground = true;

        pngCreationThread.SetApartmentState(ApartmentState.STA);

        pngCreationThread.Start();

        pngCreationThread.Join();

      }

      catch (Exception Exp)

      {

        throw Exp;

      }

      try

      {

        if (pngOutput.Length == 0)

        {

          throw new TimeoutException();

        }

      }

      catch (ObjectDisposedException)

      {

        // If the object was disposed, it means that the Stream is ready.

      }

    }

    private BitmapSource RenderToBitmap(FrameworkElement target,

                                        double width, 

                                        double height,

                                        double dpiX,

                                        double dpiY,

                                        ScaleTO thisScale)

    {

      Rect bounds;

      switch (thisScale)

      {

        case ScaleTO.OriginalSize:

          bounds = VisualTreeHelper.GetDescendantBounds(target);

          break;

        case ScaleTO.TargetSize:

          bounds = new Rect(0, 0, width,height);

          break;

        default:

          throw new ArgumentException(string.Format("The scaling mode: {0} is not supported.", thisScale.ToString()));

      }

      RenderTargetBitmap renderBitmap = new RenderTargetBitmap((int) target.ActualWidth,

        (int)target.ActualHeight, dpiX, dpiY, PixelFormats.Pbgra32);

      DrawingVisual visual = new DrawingVisual();

      using (DrawingContext context = visual.RenderOpen())

      {

        VisualBrush brush = new VisualBrush(target);

        context.DrawRectangle(brush, null, new Rect(new Point(), bounds.Size));

      }

      renderBitmap.Render(visual);

      return renderBitmap;

    }

  }

}