topic Re: Graphic scaling in ArcGIS API for Silverlight Questions

Graphic scaling

AlexAgranov — Fri, 29 Oct 2010 22:32:40 GMT

How do I scale a graphic appropriate to the current extent? Bigger as I zoom in, smaller as I zoom out?

Re: Graphic scaling

OrenGal — Mon, 01 Nov 2010 02:00:05 GMT

You can try something like this:

private void m_map_ExtentChanged(object sender, ExtentEventArgs e)
        {
            Envelope pNewEnv = e.NewExtent;

            double pWidthScreen = m_map.Width * f_glob._pixel_size;
            double pWidthMap = m_map.Extent.Width;
            double pScale = pWidthMap / pWidthScreen;

            foreach (Graphic pGraphic in pGraphicLayer)
            {
                PictureMarkerSymbol pSymbol = (PictureMarkerSymbol)pGraphic.Symbol;
                pSymbol.Width = your number/pScale;
                pSymbol.Height = your number/pScale;
            }
        }

Re: Graphic scaling

JenniferNery — Mon, 01 Nov 2010 16:55:33 GMT

You can apply ScaleTransform to the symbol template. Please look at the samples here: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#CustomSymbols

Re: Graphic scaling

AlexAgranov — Mon, 01 Nov 2010 20:34:35 GMT

You can try something like this:

private void m_map_ExtentChanged(object sender, ExtentEventArgs e)
        {
            Envelope pNewEnv = e.NewExtent;

            double pWidthScreen = m_map.Width * f_glob._pixel_size;
            double pWidthMap = m_map.Extent.Width;
            double pScale = pWidthMap / pWidthScreen;

            foreach (Graphic pGraphic in pGraphicLayer)
            {
                PictureMarkerSymbol pSymbol = (PictureMarkerSymbol)pGraphic.Symbol;
                pSymbol.Width = your number/pScale;
                pSymbol.Height = your number/pScale;
            }
        }

2 questions:

1. What is f_glob supposed to be?
2. What is "your number"?

Re: Graphic scaling

dotMorten_esri — Mon, 01 Nov 2010 22:38:20 GMT

A simpler approach is probably just to use the ElementLayer: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#ElementLayer
Notice the red box (put whatever you like there instead of the red box)

Re: Graphic scaling

OrenGal — Tue, 02 Nov 2010 14:56:06 GMT

2 questions:

1. What is f_glob supposed to be?
2. What is "your number"?

Sorry. Copied Pasted from an old app.
pixel_size and your number are constants.
pixel size is your monitor pixel size in the unit of the map (example : 0.000263 in meters)
your number is a the size of the symbol.