ReportViewer 2010 struggling with polymorphism
问题 I have a rdlc report that takes as a ReportDataSource a List<BaseClass> . BaseClass has two derived classes A and B . In the report, I group based on a property of the base class. As long as the list only contains objects of A or B , all works fine. However if I mix instances from A and B , then the report creation fails with the following message: The Group expression used in grouping '[Group Name]' references a dataset field which contains an Error: FieldValueException The property returns