ListView combobox control at the end of line

Question

Wondering how to place combobox control as last sub item for each row with some data coming from datasource. Have this code below:

LvSelMat.BeginUpdate()
Dim rodzajID as String = TreeMaterials.SelectedValue
Dim rodzajName as string = TreeMaterials.SelectedNode.Text
Dim parent as string = TreeMaterials.SelectedNode.Parent.Text

 Dim li as ListViewItem
li = LvSelMat.Items.Add(parent)
li.SubItems.Add(rodzajName)
li.SubItems.Add(rodzajID)

'Here want to add combobox...

so far i tried like this but its only showing up combobox without any other items in row...

  Dim combo as new combobox
    combo.DataSource = New Variation().GetAll
    combo.DisplayMember = "Name"
    combo.ValueMember = "Id"
    combo.dropdownstyle = ComboBoxStyle.DropDownList
    ' combo.height = item.bounds.height
    ' combo.location = new point(item.bounds.right, item.bounds.y)
    LvSelMat.controls.add(combo)