添加带有循环的listview子项

Question

Help please. Here's my table.

 ID  Item        Qty   Added Qty

 1   Ballpen      23     5

 2   Pencil       44     4

 3   Pentelpen    12     5

I want to update the items once, but when I run my program it becomes the same as the first item.

For example when click the save button, all item qty will be 28 like ballpen.

Here's my code. Thanks in advance.

                Dim lvitem As Object
                Dim iCount As Integer
                Dim iLoop As Integer
                Dim qty As Double = Val(lvPO.Items(0).SubItems(1).Text) + Val(lvPO.Items(0).SubItems(2).Text)

                iCount = lvPO.Items.Count()
                If Not lvPO.Items.Count = 0 Then
                    Do Until iLoop = lvPO.Items.Count
                        lvitem = lvPO.Items.Item(iLoop)
                        With lvitem
                        Call SEDCommand("E", "tbl_item", "  qty = '" & qty & "' WHERE itemid ='" & .SubItems(0).text & "'")
                        End With
                        iLoop = iLoop + 1
                        lvitem = Nothing
                    Loop
                    MsgBox("Purchase Order (" & tb_refpo.Text & ") is added in database!", MsgBoxStyle.Information, "SYSTEM")
                    ClearTextBox(Me)
                End If

Answer 1

As @Blackwood said, you're only calculating qty once outside the loop and using the same value for each item. You want to do it in the loop like this (and using more VB.NET style constructs makes code easier to read. This isn't VB6 :-) )

   If lvPO.Items.Count <> 0 Then
      For Each lvitem as ListViewItem in lvPO.Items
         With lvitem
            Dim qty As Double = Val(.SubItems(1).Text) + Val(.SubItems(2).Text)
            SEDCommand("E", "tbl_item", "  qty = '" & qty & "' WHERE itemid ='" & .SubItems(0).text & "'")
         End With
      Next
      MsgBox("Purchase Order (" & tb_refpo.Text & ") is added in database!", MsgBoxStyle.Information, "SYSTEM")
      ClearTextBox(Me)
   End If