How to deserialize attributes of the elements of an XML with C#?

Question

Well, I asked that question once, but I didn’t get an answer, so I’m gonna ask you again. I tried some methods I saw there that said it worked in other questions, but none of them.

I need to read this XML:

http://www.bmfbovespa.com.br/Pregao-Online/ExecutaAcaoAjax.asp?CodigoPapel=BISA3|PETR4|PETR3

And extract the attributes of the elements to play in a database. The part of the bank I already know how to do, I’m just having a hard time playing the values of the attributes in variables to parameterize. If anyone can help me, I’d appreciate it.

Answer 1

What you want is actually a deserialization: transform an XML into an object that can be read and populate variables to persist in your database.

Below I detail a script that can serve your problem.

Reading the XML

This first step requires you to open a request for the site and read the response (which is XML). The code below does this:

using System.Net.Http;

var client = new HttpClient();

var uri = new Uri("http://www.bmfbovespa.com.br/Pregao-Online/ExecutaAcaoAjax.asp?CodigoPapel=BISA3|PETR4|PETR3");
HttpResponseMessage response = await client.GetAsync(uri);

Converting the response to XML

If response is ok, we have to read XML. As your XML does not have namespace, the reading procedure is simpler and can be done as follows:

if (response.IsSuccessStatusCode)
{
    var responseString = response.Content.ReadAsStringAsync().Result;
    XmlDocument xmlDoc = new XmlDocument();
    xmlDoc.LoadXml(responseString);
    var nodes = xmlDoc.SelectNodes("/ComportamentoPapeis/*");

    foreach (XmlNode childNode in nodes)
    {
        switch (childNode.Name)
        {
            case "Papel":
                // Coloque sua lógica de negócios aqui.
                // A dica que dou pro seu caso é ler childNode.Attributes.
                break;
        }
    }

If I need to, I’ll put a proof of concept on Github.