I just looked into the Esri.ArcGISRuntime assembly (WPF version) and the API is quite different to the one described in the online documentation. I am looking for the SketchEditor class that should be present in the Esri.ArcGISRuntime.UI namespace.
Aside of this, the namespaces available in the shipped assembly are not the same as those in the online documentation.
Will the SketchEditor become available in a future release or should it already exist in the current one?