A sample to demonstrate how to drag and drop a point graphic onto a map in ArcGIS WPF Runtime v10.1.1
Credit to GalaSoft for the MVVM Light Toolkit library binaries included in this sample. You can get the package on Nuget or at http://www.galasoft.ch/mvvm/
Credit to Rainer Schuster for his implementation of the RelayCommand class. https://gist.github.com/schuster-rainer/2648922. He also credits http://msdn.microsoft.com/en-us/magazine/dd419663.aspx#id0090030 in his code.