Processing SOAP request with USING statement not working?

Question

I'm trying to refactor a console app that uses SOAP to get some API data. I saw that the original code isn't using any USING statements. I thought I would try to refactor the code to do so, however, I get an "Internal Server Error". I've looked this over an few times and I'm not seeing why this wouldn't work. If I switch back to the original code it works as expected.

This is the original code that works:

  public static string ProcessSOAPRequest(string xml, string endPoint)
    {
        XmlDocument doc = new XmlDocument();
        doc.LoadXml(xml);

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(endPoint);
        req.Timeout = 100000000;
        req.Method = "POST";

        Stream objStream = req.GetRequestStream();
        doc.Save(objStream);
        objStream.Close();

        WebResponse resp = req.GetResponse();
        objStream = resp.GetResponseStream();

        StreamReader r = new StreamReader(objStream);
        string data = r.ReadToEnd();

        return data;
    }

This is my attempt at refactoring with USING.

public static string ProcessSOAPRequest(string xml, string endPoint)
{
    XmlDocument doc = new XmlDocument();
    doc.LoadXml(xml);

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(endPoint);
    request.Timeout = 100000000;
    request.Method = "POST";

    using (WebResponse response = request.GetResponse())
    using (Stream stream = response.GetResponseStream())
    using (StreamReader reader = new StreamReader(stream))
    {
        return reader.ReadToEnd();
    }
}

UPDATE: another attempt based on the responses. This time in the second USING statement it says that I can't use stream = response.GetResponseStream(); because "stream" is in a using statement.

var data = string.Empty;
using (Stream stream = request.GetRequestStream())
{
    doc.Save(stream);

    using (WebResponse response = request.GetResponse())
    {
        stream = response.GetResponseStream();

        using (StreamReader reader = new StreamReader(stream))
        {
            data = reader.ReadToEnd();
        }
    }
}            

return data;

The implicit return probably isn't helping you. Did you try assigning the result and returning outside of the using? — BradleyDotNET, Nov 16 '16 at 19:59
As @jdweng pointed out, you never added the contents of `doc` to the `request` in the new code. — Eris, Nov 16 '16 at 20:19
The variable declared in a `using` statement is treated as `readonly`. I suggest you to declare a new variable and assign the `response` to that. — Nikkster, Nov 16 '16 at 20:32

score 1 · Accepted Answer · edited May 23 '17 at 12:24

Answer to the update:

The variable declared in a using statement is treated as readonly. I suggest you to declare a new variable and assign the response to that. Why? - Why is a variable declared in a using statement treated as readonly?

var data = string.Empty;
using (Stream stream = request.GetRequestStream())
{
    doc.Save(stream);

    using (WebResponse response = request.GetResponse())
    {
        var responseStream = response.GetResponseStream();
        if (responseStream != null)
        {
            using (StreamReader reader = new StreamReader(responseStream))
            {
                data = reader.ReadToEnd();
            }
        }
    }
}            

return data;

should work.

Processing SOAP request with USING statement not working?

1 Answers1