C# How to correctly pass parameters in a WebRequest POST request?

Question

C++ / C#

I'm trying to create a request for an authorization form, if the data is correct - there will be a redirect to another page, if not correct - it will return the authorization form.

WebRequest request = WebRequest.Create("http://www.request.com/");
request.Proxy = new WebProxy(new Uri("http://myproxy.ru"));
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";

NameValueCollection outgoingQueryString = HttpUtility.ParseQueryString(String.Empty);

outgoingQueryString.Add("_method", "POST");
outgoingQueryString.Add("data[User][email]", "[email protected]");
outgoingQueryString.Add("data[User][password]", "QWErty01");

byte[] byteArray = new ASCIIEncoding().GetBytes(outgoingQueryString.ToString());

request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
WebResponse response = request.GetResponse();

dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string responseFromServer = reader.ReadToEnd();

reader.Close();
dataStream.Close();
response.Close();

In responseFromServer I find exactly the authorization form, as if the data is not correct.
At the same time, the same JS request is processed perfectly

$.ajax({
  type: "POST",
  url: 'http://cora-request.com/',
  data: { '_method': 'POST', "data[User][email]": "[email protected]", "data[User][password]": "QWErty01" },
  success: function(response){ console.log(response) }
});

Parameters are passed in the same way

_method=POST&data%5bUser%5d%5bemail%5d=hwac%40my.ru&data%5bUser%5d%5bpassword%5d=QWErty01 -> с#
_method=POST&data%5BUser%5D%5Bemail%5D=hwac%40my.ru&data%5BUser%5D%5Bpassword%5D=QWErty01 -> js

What could be the reason ?

Answer 1

Looking at the jquery documentation , $.ajax defaults to a ContentType of 'application/x-www-form-urlencoded; charset=UTF-8'
Means it is necessary to send data in UTF-8.
Next, you use a NameValueCollection to generate the request body, which does not properly encode special characters.
To correctly create an urlencoded request body, it is better to use the FormUrlEncodedContent class