Hi Nassim,
Thanks for your interest in Syncfusion Products.
You need to have a custom celltype for this support to have both image and text inside a cell. To create a custom celltype, it requires a model class and a renderer class. The model class handles the serialization requirements for the control and creates the renderer class. The renderer class handles the UI requirements of the cell. After creating the custom celltype, it has to be registered through grid.TableModel.CellModels.Add function.
Please refer the below sample in GridControl, that helps in having both image and text in a cell using custom celltype. You can use the same celltype for your GridGroupingControl also. In the QueryCellStyleInfo event you can set the e.Style.CellType to be your custom celltype for the desired cells.
Sample for reference:
http://www.syncfusion.com/Support/user/uploads/CustomResizeTofit_ca1b3509.zipLet me know if this helps.
Regards,
Nisha