VB.net innerhalb einer Listenvariable Aktualisierung für jede Schleife

Question

Dim aProductos As List(Of Producto) 
Dim aRegistros As New List(Of Registro) 
Dim selectedProd As New Producto 

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
    'Add to cart 
    Dim insert As Boolean = True 

Problem beginnt vvv HIER

For Each reg In aRegistros 
     If (reg.id_prod = Integer.Parse(lbCodigo.Text)) Then 

      Dim r As New Registro 
      r.id_prod = reg.id_prod 
      r.cantidad = reg.cantidad + Integer.Parse(nudUni.Value.ToString) 
      reg = r 
      insert = False 
     End If 
    Next 

PROBLEM AUSBAU HIER ^^^

If insert Then 
     Try 
      Dim r As New Registro 
      r.id_prod = selectedProd.cod 
      r.cantidad = Integer.Parse(nudUni.Value.ToString) 
      aRegistros.Add(r) 
     Catch ex As Exception 
      MsgBox("Create and insert register: " + ex.Message) 
     End Try 
    End If 
    MostrarFactura() 
End Sub 

Private Sub MostrarFactura() << Updates a listview to see the products you got 
    listaProd.Items.Clear() 
    For Each registro In aRegistros 
     For Each producto In aProductos 
      If registro.id_prod = producto.cod Then 
       MsgBox(registro.cantidad) 
       listaProd.Items.Add(producto.nombre + " --- " + registro.cantidad.ToString + " -> " + (producto.precio * registro.cantidad).ToString + "€") 
      End If 
     Next 
    Next 
End Sub 

Das Problem ist, dass ich aktualisieren " reg "aber wenn die Schleife endet reg aktualisiert nicht den Wert innerhalb der Liste

Vielen Dank im Voraus: S

Answer 1

Anstatt eine For Each zu verwenden, können Sie eine Ganzzahl verwenden, um die Position in der Liste anzugeben.

For x = 0 to aRegistros.Count -1 
    Dim reg = aRegistros(x) 
    Dim r As New Registro 
    r.id_prod = reg.id_prod 
    r.cantidad = reg.cantidad + Integer.Parse(nudUni.Value.ToString) 
    aRegistros(x) = r 
    insert = False 
Next