Silverlight 3: Converting XML stroke collection back into a strokecollection?

Question

I have a silverlight app that allows the user to draw on it and save the drawing.

The strokecollection in the canvas is converted to xml attributes and stored in the database.

the only problem i have now is converting the xml back into a stroke collection.

my strokes are stored as such:

<Strokes>    
  <Stroke>    
    <Color A="255" R="0" G="0" B="0" />      
    <OutlineColor A="0" R="0" G="0" B="0" />      
  <Points>
    <Point X="60" Y="57" PressureFactor="0.5" />        
    <Point X="332" Y="52" PressureFactor="0.5" />      
  </Points>      
  <Width>3</Width>      
  <Height>3</Height>    
  </Stroke>  
</Strokes>

Answer 1

Here is my solution... it appears I thought it was too confusing before I actually sat down and looked at it:

private StrokeCollection CreateStrokeCollectionfromXML(string XMLStrokes)
    {
        XElement xmlElem;
        try
        {
            xmlElem = XElement.Parse(XMLStrokes);
        }
        catch (XmlException ex)
        {
            return new StrokeCollection();
        }
        StrokeCollection objStrokes = new StrokeCollection();
        //Query the XML to extract the Strokes
        var strokes = from s in xmlElem.Descendants("Stroke") select s;
        foreach (XElement strokeNodeElement in strokes)
        {
            var color = (from c in strokeNodeElement.Descendants("Color")
                        select c).FirstOrDefault();
            DrawingAttributes attributes = new DrawingAttributes();

            byte colorA = Convert.ToByte(color.Attribute("A").Value);
            byte colorR = Convert.ToByte(color.Attribute("R").Value);
            byte colorG = Convert.ToByte(color.Attribute("G").Value);
            byte colorB = Convert.ToByte(color.Attribute("B").Value);

            attributes.Color = Color.FromArgb(colorA, colorR, colorG, colorB);

            var outlineColor = (from oc in strokeNodeElement.Descendants("OutlineColor")
                                select oc).FirstOrDefault();

            byte outlineColorA = Convert.ToByte(outlineColor.Attribute("A").Value);
            byte outlineColorR = Convert.ToByte(outlineColor.Attribute("R").Value);
            byte outlineColorG = Convert.ToByte(outlineColor.Attribute("G").Value);
            byte outlineColorB = Convert.ToByte(outlineColor.Attribute("B").Value);

            attributes.OutlineColor = Color.FromArgb(outlineColorA, outlineColorR, outlineColorG, outlineColorB);

            attributes.Width = Convert.ToInt32(strokeNodeElement.Descendants("Width").FirstOrDefault().Value);
            attributes.Height = Convert.ToInt32(strokeNodeElement.Descendants("Height").FirstOrDefault().Value);

            var points = from p in strokeNodeElement.Descendants("Point")
                         select p;
            StylusPointCollection pointData = new System.Windows.Input.StylusPointCollection();

            foreach (XElement point in points)
            {
                double Xvalue = Convert.ToDouble(point.Attribute("X").Value);
                double Yvalue = Convert.ToDouble(point.Attribute("Y").Value);
                pointData.Add(new StylusPoint(Xvalue, Yvalue));
            }

            Stroke newstroke = new Stroke();
            newstroke.DrawingAttributes = attributes;
            newstroke.StylusPoints.Add(pointData);
            //add the new stroke to the StrokeCollection
            objStrokes.Add(newstroke);
        }
        return objStrokes;
    }

Answer 2

Here is your code heavily factored:-

private StrokeCollection CreateStrokeCollection(string XMLStrokes)
{
  XElement xmlElem;
  try
  {
    return CreateStrokeCollect(XElement.Parse(XMLStrokes).Root);
  }
  catch (XmlException ex)
  {
    return new StrokeCollection();
  }
}

private StrokeCollection CreateStrokeCollection(XElement elem)
{  
  StrokeCollection result= new StrokeCollection();
  foreach (XElement elem in xmlElement.Elements("Stroke"))
  {
     result.Add(CreateStroke(elem));
  }
  return result;
}


private Stroke CreateStroke(XElement elem)
{
  var result = new Stroke();
  result.DrawingAttributes = CreateAttributes(elem);
  result.StylusPoints.Add(CreatePointCollection(elem.Element("Points"));
  return result;
}

private StylusPointCollection CreatePointCollection(XElement elem)
{
  var result = new StylusPointCollection();
  foreach (XElment pointElem in elem.Elements("Point"))
  {
    result.Add(CreateStylusPoint(pointElem));
  }
  return result;
}

private StylusPoint CreateStylusPoint(XElement elem)
{
    double x = Convert.ToDouble(point.Attribute("X").Value);
    double y = Convert.ToDouble(point.Attribute("Y").Value);
    return new StylusPoint(x, y);
}

private DrawingAttributes CreateAttributes(XElement elem)
{
   var result = new DrawingAttributes();
   result.Color = CreateColor(elem.Element("Color"));
   result.OutlineColor = CreateColor(elem.Element("OutlineColor"));
   result.Width = Convert.ToInt32(elem.Element("Width").Value);
   result.Height = Convert.ToInt32(elem.Element("Height").Value);
   return result ;
}

private Color CreateColor(XElement elem)
{
  byte colorA = Convert.ToByte(color.Attribute("A").Value);
  byte colorR = Convert.ToByte(color.Attribute("R").Value);
  byte colorG = Convert.ToByte(color.Attribute("G").Value);
  byte colorB = Convert.ToByte(color.Attribute("B").Value);

  return Color.FromArgb(colorA, colorR, colorG, colorB);       
}