FeatureDataGrid does not display rows with null values as of version 2.2

Question

Since Version 2.2 the feature data grid does not display rows containing null values anymore. A Silverlight error is raised instead: Unhandled Error in Silverlight Application All rows must be of type 'System.Nullable`1[System.Double]' for the 'DiffPct' attribute. at ESRI.ArcGIS.Client.Toolkit.FeatureDataGrid.AllAttributesMatch(PropertyInfo[] itemsSourceProperties, IDictionary`2 graphicAttributes) at ESRI.ArcGIS.Client.Toolkit.FeatureDataGrid.UpdateItemsSource(Object sender, NotifyCollectionChangedEventArgs e) at ESRI.ArcGIS.Client.Toolkit.FeatureDataGrid.Graphics_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item) at ESRI.ArcGIS.Client.GraphicCollection.InsertItem(Int32 index, Graphic item) at System.Collections.ObjectModel.Collection`1.Add(T item) at ESRI.ArcGIS.Client.FeatureLayer.addGraphic(Graphic g) at ESRI.ArcGIS.Client.FeatureLayer.task_QueryComplete(Object sender, QueryEventArgs args) at ESRI.ArcGIS.Client.Tasks.QueryTask.OnExecuteCompleted(QueryEventArgs args) at ESRI.ArcGIS.Client.Tasks.QueryTask.<>c__DisplayClass6.b__4(FeatureSet fs, Exception ex) at ESRI.ArcGIS.Client.Tasks.FeatureSet.<>c__DisplayClass2.b__0(Object s, RunWorkerCompletedEventArgs e) at System.ComponentModel.BackgroundWorker.OnRunWorkerCompleted(RunWorkerCompletedEventArgs e) at System.ComponentModel.BackgroundWorker.b__1(Object state) An example of a typical Binding of type DataGridTextColumn is this one: Prior to toolkit version 2.2 it would just work.

stefanschlaefli · Answer

Just for the record: this issue seems to have disappeared in API version 2.3.

ChrisLampe · Answer

I am also experiencing the same problem.  I have loaded the graphics layer from MapIT and when I assign it to the data grid in code i.e.:
 MyDataGrid.GraphicsLayer = gLayer
an exception is thrown detailing that not all rows are of the expected type (varies depending on the data received from MapIT).  It generally appears to be associated with columns that have NULL data.  
If I drop back to 2.1 the problem goes away.

stefanschlaefli · Answer

Yes, I rolled back to version 2.1 and the problem was gone. I didn't test every single graphic's DiffPct for it's type yet.