How to send xml through an HTTP request, and receive it using ASP.NET MVC?

Question

I am trying to send an xml string through an HTTP request, and receive it on the other end. On the receiving end, I am always getting that the xml is null. Can you tell me why that is?

Send:

    var url = "http://website.com";
    var postData = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?><xml>...</xml>";
    byte[] bytes = System.Text.Encoding.ASCII.GetBytes(postData);

    var req = (HttpWebRequest)WebRequest.Create(url);

    req.ContentType = "text/xml";
    req.Method = "POST";
    req.ContentLength = bytes.Length;

    using (Stream os = req.GetRequestStream())
    {
        os.Write(bytes, 0, bytes.Length);
    }

    string response = "";

    using (System.Net.WebResponse resp = req.GetResponse())
    {
        using (StreamReader sr = new StreamReader(resp.GetResponseStream()))
        {
            response = sr.ReadToEnd().Trim();
        }
     }

Receive:

[HttpPost]
[ValidateInput(false)]
public ActionResult Index(string xml)
{
    //xml is always null
    ...
    return View(model);
}

score 10 · Accepted Answer · answered Aug 19 '13 at 19:15

10

I was able to get this working like so:

[HttpPost]
[ValidateInput(false)]
public ActionResult Index()
{
    string xml = "";
    if(Request.InputStream != null){
        StreamReader stream = new StreamReader(Request.InputStream);
        string x = stream.ReadToEnd();
        xml = HttpUtility.UrlDecode(x);
    }
    ...
    return View(model);
}

However, I am still curious why taking the xml as a parameter does not work.

answered Aug 19 '13 at 19:15

Kalina

5,504
16
64
101

Thanks it also worked for me.. .If you are posting it as a stream you have to read input stream to get data.To Receive in "xml" vairable you must send this with query string as post parameter – Kashif Hanif Aug 11 '17 at 14:46

score 0 · Answer 2 · edited May 23 '17 at 11:45

I believe this is because you've specified req.ContentType = "text/xml";.

If I remember correctly when you define your controller using a "primitive" type (string being a "primitive" type here)

public ActionResult Index(string xml){}

MVC will try to look for xml either in a query string or in the posted form data (html input field). But if you send something more complex to the server MVC will wrap it in a specific class.

For example, when you upload several files to the server you can accept them as follows in your controller

public ActionResult Index(IEnumerable<HttpPostedFileBase> files){}

So my guess is that you have to accept the text/xml stream in the controller using the correct class.

Update:

It seems there isn't such a class because you accept a data stream (and it's not coming from input element). You could write your own model binder to accept xml document. See discussions below.

Reading text/xml into a ASP.MVC Controller

How to pass XML as POST to an ActionResult in ASP MVC .NET

How to send xml through an HTTP request, and receive it using ASP.NET MVC?

2 Answers2