[ابو انس]

كود :

   For i As Integer = 0 To DataGridView1.Rows.Count - 1

           DataGridView1.Rows(i).Cells(3).Value = DataGridView1.Rows(i).Cells(0).Value & " " & DataGridView1.Rows(i).Cells(1).Value & " " & DataGridView1.Rows(i).Cells(2).Value
       Next