Silverlight pie chart sizing

Question

Hi,
I'm relatively new to Silverlight and I'm trying to adapt the pie chart sample.  Basically what I want is to be able to bind the scale of the chart to a dependency property in the .cs file.  Unfortunately, I'm unable to get access to either the RenderTransform or the ScaleTransform.  I've tried a couple of different ways to get access to it, including using IValueConverter and TemplateBinding.  Obviously there is something I'm missing, but I don't know what it is.  A few pointers would be very helpful, if possible.

Thanks in advance,

Joe White

JoeWhite · Answer

Dominique,
I used your third suggestion and modified the animation to match.  It worked perfectly!  I really appreciate all of your help.

Joe

DominiqueBroux · Answer

pieChartMarkerSymbol.ScaleFactor = scaleFactor;

Where is coming pieChartMarkerSymbol from?  
 
If it's an unique instance, that can't work because all graphics are sharing the same symbol and so the same scaleFactor (the last one you initialized).
 
There are a few options to avoid this issue:
     - create a symbol by graphic (not recommended for performances)
     - create a few symbols with various scales and use them in a classBreakRenderer that you affect to your layer 
     - store the scale in an attribute of your graphics (e.g. graphic.Attributes["SCALE"] = scaleFactor;) and change your symbol in order to bind to this attribute (e.g. <ScaleTransform ScaleX="{Binding Attributes[SCALE]}" ScaleY="{Binding Attributes[SCALE]}" />)
 
Note : In the latest case you don't need anymore the ScaleFactor dependency property.

JoeWhite · Answer

Hi, Domonique,
Oviously I'm still screwing this up.  I've disabled the animations on hover, just to make sure they don't interefere, and setting a binding for a ScaleFactor dependency property in the class. When I do this, it acts like the binding can't be found, and each symbol is being scaled to 1.0.  
The scale code is below:

Graphic graphic = new Graphic()
int importValue = random.Next(1000000000);
double scaleFactor = (double)importValue / 1000000000; //median value
graphic.Attributes["IMPORT"] = importValue;
graphic.Attributes["EXPORT"] = random.Next(1000000000);
pieChartMarkerSymbol.ScaleFactor = scaleFactor;
graphic.Symbol = pieChartMarkerSymbol;
 graphicsLayer.Graphics.Add(graphic);

One additional question:  Does this set the scale on all of the PieChartMarkerSymbols in a given Layer?  If so, that's not exactly what I'm looking for.  I would like to set a different scale for each PieChartMarkerSymbol.

In any case, thanks for the replies.  If you have any other pointers, I'd really appreciate them.

Thanks

Joe