I think you can handle the Model.QueryRowHeght to do what you described. Here is code that worked in the MultiRowRecord sample.
//hook and unhook the event in the toggleMultiRowCheckBox_CheckedChanged handler so the event only fires when the mulitple rows are checked
gridModel.QueryRowHeight += new GridRowColSizeEventHandler(grid_QueryRowHeight); //hooking code
gridModel.QueryRowHeight -= new GridRowColSizeEventHandler(grid_QueryRowHeight); //unhooking code
//the handler
private void grid_QueryRowHeight(object sender, GridRowColSizeEventArgs e)
{
if(this.toggleMultiRowCheckBox.Checked)
{
GridModel gridModel = sender as GridModel;
if(gridModel != null)
{
int row = e.Index - gridModel.Cols.HeaderCount;
if(row % 3 == 0)
{
e.Size = 30;
e.Handled = true;
}
else if(row % 3 == 1)
{
e.Size = 20;
e.Handled = true;
}
}
}
}