I have a SharePoint 2010 sandbox solution with a webpart (with Silverlight). My webpart has a custom (string) property. It seems it is not an easy task to update this property remotely. I have been using WebPartPages.asmx web serivce of SharePoint but its methods for load/update of webparts don't work in sandbox solutions, because the webpart is wrapped in another one, called SPUserCodeWebPart. So, is there a way to bypass this restriction?
I have noticed, that if I expose the property (WebBrowsable attribute = true) I can modify it in the toolpane on the left. However, I don't like this way because I use this property as a property bag (XML with my custom settings).