Optimize foreach

Question

I need to check the items from listaContrato exist in the listaPendencia, if I don’t exist enable to false to be disabled on screen.

What can I do to improve the performance of foreach below? Both lists are List<>.

If there are solutions that are not foreach are also welcome.

foreach (System.Windows.Controls.CheckBox item in pendenciaController.ListaCliente)
{
    item.IsEnabled = false;

    foreach (Pendencia pendencia in pendenciaController.ListaPendencia)
    {
        if (pendencia.ClienteNome.Equals(item.Content))
        {
            item.IsEnabled = true;
            break;
        }
    }
}

Answer 1

I have no way to test, but try the following LINQ (but I doubt it will be faster than one).

var lista = 
    from checkBox in pendenciaController.ListaCliente
    join pendencia in pendenciaController.ListaPendencia on checkBox.Content equals pendencia.ClienteNome into pendencias
    from pendencia in pendencias.DefaultIfEmpty()
    select new { CheckBox = checkBox, Pendencia = pendencia };

foreach (var item in lista)
{
    item.CheckBox.IsEnabled = item.Pendencia != null;
}

Answer 2

Apparently only to improve by breaking the loop once you find what you expect. Without seeing a larger context you can’t improve more.

You can write this in the most idiomatic way for C, you can avoid this flag:

foreach (var item in pendenciaController.ListaContrato) {
    foreach (var pendencia in pendenciaController.ListaPendencia) {
        if (pendencia.Contrato.Equals(item.Content)) {
            item.IsEnabled = false;
            break;
        }
    }
}

I put in the Github for future reference.