Adding values present in a List

Question

I’ll explain what I want to do.
I have this List:

public static List<Cliente> Clientes = new List<Cliente>();

public class Cliente
{
    public string Nome { get; set; }
    public List<ProdutoComprado> Produtos { get; set; }
}

public class ProdutoComprado
{
    public string NomeProduto { get; set; }
    public string ValorProduto { get; set; }
}

As you can see, every customer has their products. What I need is to add the values of the constant Valorproduto of all products of a particular customer. I believe that to do this I will have to use Sum to add the variables. I was trying something like:

Cliente cliente = Clientes[listaClientes.SelectedIndex];

int total = 0;
foreach (var s in cliente.Produtos)
{
    total = s.ValorProduto.Sum(x => Convert.ToInt32(x));
}

string soma = string.Format("\n\n\nValor total: {0}", total);

This is not working. I am having as output the value 317.

Answer 1

Try changing the code to the following:

Cliente cliente = Clientes[listaClientes.SelectedIndex];

int total = cliente.Produtos.Sum(x => Convert.ToInt32(x.ValorProduto));

string soma = string.Format("\n\n\nValor total: {0}", total);

The LINQ Sum acts by traversing and summing the list elements, so the external foreach is unnecessary. Another point that is flawed in your code is that you are always overwriting the total and not incrementing it (replacing the = by +=).