Private Sub DataTableRowChanging()
     Dim custTable As New DataTable("Customers")
     ' add columns
     custTable.Columns.Add("id", Type.GetType("System.Int32"))
     custTable.Columns.Add("name", Type.GetType("System.String"))
     custTable.Columns.Add("address", Type.GetType("System.String"))

     ' set PrimaryKey
     custTable.Columns("id").Unique = True
     custTable.PrimaryKey = New DataColumn() {custTable.Columns("id")}

     ' add a RowChanging event handler for the table.
     AddHandler custTable.RowChanging, _
            New DataRowChangeEventHandler(AddressOf Row_Changing)


     ' add ten rows
     Dim id As Integer
     For id = 1 To 10
         custTable.Rows.Add( _
New Object() {id, String.Format("customer{0}", id), _
         String.Format("address{0}", id)})
     Next

     custTable.AcceptChanges()

     ' change the name column in all the rows
     Dim row As DataRow
     For Each row In custTable.Rows
         row("name") = String.Format("vip{0}", row("id"))
     Next

 End Sub

 Private Sub Row_Changing(ByVal sender As Object, _
 ByVal e As DataRowChangeEventArgs)
     Console.WriteLine("Row_Changing Event: name={0}; action={1}", _
      e.Row("name"), e.Action)
 End Sub