Hi Qingdong,
Minimally, there are three events that you need to handle in order to implement a readonly virtual grid. In the QueryCellInfo, you provide the actual data from your external data source. In the QueryRowCount, you provide the number of rows that are in your virtual grid. And finally, in the QueryColCount, you provide the number of columns that are in the virtual grid.
Please refer to the KnowledgeBase Article for more details.
Click=>EssentailGrid=>WindowsForms=>QuickStart-VirtualGrid categoryBest Regards,
Haneef