I want to update my data in a data grid view by other Form.

Question

Heloo Guys I am making a software but there has been a big error for me i want the data to be updated by other form but when ever i try to do it it always updates the whole data gridview records not just one but all. I also tried this statement:int roll_no = Convert.ToInt32(homepage.bunifuDataGridView1.SelectedRows[0].Cells[0].Value.ToString()); so that the data in the grid view will update records by their id but it didnot worked gives me an error saying:

System.ArgumentOutOfRangeException: 'Index was out of range. Must be non-negative and less than the size of the collection.

Parameter name: index'

Plz is there anyone who can help me...

Roll_no Index is 0 but it gives me an error.