Hi Fady,
Single Column Sorting :
You can sort columns using SortByColumn method in this.grid.Data.
Refer to this browser sample : GridControlSort ( \\windows\Grid.Windows\Samples\Quick Start\GridControlSort ) for more details.
MultiColumn Sorting :
To sort on multiple columns, you would need to derive a Comparer class that compares things using your primary column. When they are equal, you need to compare your secondary columns, and so on until you run out of columns to compare or your comparison does not match.
For a sample, refer to this forum thread :
MultiColumnSort_GridControl
Best regards,
Madhan