วิธีการ select combobox ใน datagridview เพื่อไปแสดงบนอีก column (VB)

   Private Sub DataGridView1_EditingControlShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
        If TypeOf e.Control Is ComboBox Then
            If DataGridView1.CurrentCell.ColumnIndex = 0 Then
                Dim cb As ComboBox = TryCast(e.Control, ComboBox)

                'remove handler if it was added before
                RemoveHandler cb.SelectedIndexChanged, AddressOf ColumnCombo1SelectionChanged
                AddHandler cb.SelectedIndexChanged, AddressOf ColumnCombo1SelectionChanged
    
            End If
        End If
    End Sub

    Private Sub ColumnCombo1SelectionChanged(sender As Object, e As EventArgs)
        Dim combo As ComboBox = CType(sender, ComboBox)
        'ค้นหาข้อมูลที่นี่ โดยใช้ combo.Text เป็นเงื่อนไขค้นหา
    End Sub

Private Sub ColumnCombo1SelectionChanged(sender As Object, e As EventArgs)

Dim combo As ComboBox = CType(sender, ComboBox)
'ค้นหาข้อมูลที่นี่ โดยใช้ combo.Text เป็นเงื่อนไขค้นหา

Dim dr As OleDbDataReader
Dim s As String = "select * from product where Pid = '" & combo.Text & "' "
dr = ExecuteReader(s)
 dr.Read()

dgv.CurrentRow.Cells(1).Value= dr.Item("Pname")
dgv.CurrentRow.Cells(2).Value= dr.Item("bar")
dgv.CurrentRow.Cells(3).Value= dr.Item("bar")
dgv.CurrentRow.Cells(4).Value= dr.Item("bar")
dgv.CurrentRow.Cells(5).Value= dr.Item("bar")
dgv.CurrentRow.Cells(6).Value= dr.Item("bar")
dgv.CurrentRow.Cells(7).Value= dr.Item("bar")

    Private Sub cal()
        Dim i As Integer = 0

        Dim total As Integer = 0
        For i = 0 To dgv_SO.Rows.Count - 1

            total = CDbl(dgv_SO.Rows(i).Cells(2).Value) * CDbl(dgv_SO.Rows(i).Cells(4).Value)
            total = dgv_SO.Rows(i).Cells(5).Value
        Next

        tb_total.Text = total.ToString("##,##0.0")


    End Sub

total = CDbl(dgv_SO.Rows(i).Cells(2).Value) * CDbl(dgv_SO.Rows(i).Cells(4).Value)
        total = dgv_SO.Rows(i).Cells(5).Value

total = CDbl(dgv_SO.Rows(i).Cells(2).Value) * CDbl(dgv_SO.Rows(i).Cells(4).Value)
dgv_SO.Rows(i).Cells(5).Value =   total 'ให้คอลัมที่ 5 โชว ค่า ที่ รวมมาได้

Private Sub DataGridView1_CellEndEdit(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellEndEdit
        Try
            DataGridView1(5, e.RowIndex).Value = CDbl(DataGridView1(2, e.RowIndex).Value) * CDbl(DataGridView1(4, e.RowIndex).Value)
        Catch ex As Exception

        End Try
        'ใส่ Try ไว้ เผื่อค่าที่กรอกไปมีปัญหาไปงั้นๆแหละ
    End Sub

Private Sub cal()
      Dim i As Integer = 0
      Dim total As Integer = 0
      For i = 0 To dgv_SO.Rows.Count - 1

          total = CDbl(dgv_SO.Rows(i).Cells(2).Value) * CDbl(dgv_SO.Rows(i).Cells(4).Value)
          dgv_SO.Rows(i).Cells(5).Value = total

           MessageBox.Show(total) 'แค่อยากรู้ว่ามันคำนวณให้เรารึป่าว
      Next

      tb_total.Text = total.ToString("##,##0.0")


  End Sub

Private Sub CalVAT()
 txtVat.text = VATttttttttt 'คำนวณ ค่า VAT ออกมา
 txtTotalSumVat.txt =CDbl( txtTotal.text) +CDbl( txtVat.text )
End Sub

Private Sub ComboBox1_TextChanged(sender As Object, e As EventArgs) Handles ComboBox1.TextChanged
CalVAT()
End Sub

Private Sub dgv_SO_CellEndEdit(sender As Object, e As DataGridViewCellEventArgs) Handles dgv_SO.CellEndEdit
        Try
            dgv_SO(5, e.RowIndex).Value = CDbl(dgv_SO(2, e.RowIndex).Value) * CDbl(dgv_SO(4, e.RowIndex).Value)
               CalVAT()
        Catch ex As Exception
              
        End Try

    End Sub