Clicking display attribute button in EditorWidget, will cancel any active command so you cannot use this in combination with Editor.Select command. You can use subscribe to EditorWidget.EditCompleted and use FeatureDataForm instead: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#ToolkitFeatureDataForm
void EditorWidget_EditCompleted(object sender, Editor.EditEventArgs e)
{
foreach (var edit in e.Edits)
{
if (edit.Graphic.Selected)
{
myFDF.FeatureLayer = edit.Layer as FeatureLayer;
myFDF.GraphicSource = edit.Graphic;
}
}
}
This seem related to updating cursor: http://forums.arcgis.com/threads/44498-Change-Mouse-Cursor-when-hovering-a-feature