I have built an addin for Silverlight Viewer (version 1.0.1, Silverlight API client version 2.4, ArcGIS Server 10.0). One of the tools is an export map function, I simply want to export a JPG image of the map control. The map contains a single layer, the tiled Topographic Map service hosted on ArcGIS Online.
When accessing the WriteableBitmap I am getting a security exception (???WriteableBitmap has protected content. Pixel access is not allowed???). This is expected as ArcGIS Online is on a different domain. To get around this, I created a proxy and assigned the proxy URL to the Topographic Map layer inside the Builder application. Still getting the error message.
If I create a simple Silverlight application with a map control and the Topographic map layer, the security exception is no longer raised if I specify the ProxyURL property for the layer.
Is the proxy expected to work in this situation? I know I can create a preview map control in my addin window, copy the map layers and graphics from main map and then export the preview map, but I would like to avoid doing this.
Thanks
Alex