Hi,

The grid cannot do this - the rows come from the data and the data is not persisted by the grid, it's in the data source and therefore separate from the grid. So there's no way the grid could persist state information like the expanded or selected state of a row without also duplicating your entire set of data.

If you want to code this yourself, I'd recommend storing some primary key information from each row along with the expanded state. Then you could loop through the grid rows and restore the expanded state from your stored data.