how to make POST request in C# - c#

im trying to create a post request to collect date from web site
my request should be like this :
POST /api/recent HTTP/1.1
Host: domain.org
Content-Type:application/x-www-form-urlencoded
api_token=YOUR_TOKEN_VALUE
i trying this 0 error but is not working :
private const string URL = " MY url";
private const string Parameters = "api_key= my key";
public static string HttpPost(string URI, string Parameters)
{
System.Net.WebRequest req = System.Net.WebRequest.Create(URI);
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(Parameters);
req.ContentLength = bytes.Length;
System.IO.Stream os = req.GetRequestStream();
os.Write(bytes, 0, bytes.Length); //Push it out there
os.Close();
System.Net.WebResponse resp = req.GetResponse();
if (resp == null) return null;
System.IO.StreamReader sr =
new System.IO.StreamReader(resp.GetResponseStream());
return sr.ReadToEnd().Trim();
}

Try to create your POST requests using RestSharp
Source code and some tutorials available on GitHub, tons of questions here on SO

Related

Send data from c# to a php page and display on php

I'm using altervista which dosn't allow a connection directly with the database but only from php scripts stored on the server. Searching on the web I foud the solution, passing the data from c# to the php's URL either with Get or Post method. Then I wrote this little code in c#
private void SubmitData()
{
try
{
string url = "";
string str = "test";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.Method = "POST";
string Data = "message=" + str;
byte[] postBytes = Encoding.ASCII.GetBytes(Data);
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = postBytes.Length;
Stream requestStream = req.GetRequestStream();
requestStream.Write(postBytes, 0, postBytes.Length);
requestStream.Close();
HttpWebResponse response = (HttpWebResponse)req.GetResponse();
Stream resStream = response.GetResponseStream();
var sr = new StreamReader(response.GetResponseStream());
string responseText = sr.ReadToEnd();
}
catch (WebException)
{
MessageBox.Show("Please Check Your Internet Connection");
}
}
Php code
<?php
if (isset($_POST['message']))
{
$msg = $_POST['message'];
echo $msg;
}
else
{
echo "couldn't display data";
}
?>
It doen't ever seem that it sends some data to it.
Thank you in advance.

C# WebRequest - HTTP: 403 Forbidden ('_xsrf' argument missing from POST)

I'm stucked here at getting a WebResponse from HTTPWebRequest.
The WebRequest.GetResponse() Method throws a WebException
("500 Internal Server Error"). When i read the returned HTML it says:
HTTP 403: Forbidden ('_xsrf' argument missing from POST)
Anyone knows this Error or knows what Im doing wrong?
(Im trying to log in to a Website using POST)
EDIT:
My sourcecode:
private String GetLoginCookies(String pHTTPurl, String pUserIDwithFormID, String pPasswordWithFormID)
{
String loginPageUrl = pHTTPurl;
CookieContainer cookieContainer = new CookieContainer();
var Request = (HttpWebRequest)WebRequest.Create(loginPageUrl);
Request.CookieContainer = cookieContainer;
Request.Method = "GET";
WebResponse Response = Request.GetResponse();
HttpWebResponse HttpResponse = Response as HttpWebResponse;
CookieCollection cookies = null;
if (HttpResponse != null)
{
//Cookies die benötigt werden um den Loginvorgang abzuschließen
cookies = HttpResponse.Cookies;
}
string formParams = string.Format(pUserIDwithFormID + "&" + pPasswordWithFormID);
Request = (HttpWebRequest)WebRequest.Create(loginPageUrl);
Request.CookieContainer = cookieContainer;
Request.UserAgent = "I am not a Bot! Ok maybe..";
WebResponse resp = null;
Request.ContentType = "application/x-www-form-urlencoded";
Request.Method = "POST";
byte[] bytes = Encoding.ASCII.GetBytes(formParams);
Request.ContentLength = bytes.Length;
using (Stream os = Request.GetRequestStream())
{
os.Write(bytes, 0, bytes.Length);
}
try
{
resp = Request.GetResponse();
using (StreamReader sr = new StreamReader(resp.GetResponseStream()))
{
String TestResponse = sr.ReadToEnd();
}
}
catch (WebException WE)
{
DebugConsole.AppendText("HTTP Error:" + WE.Message + Environment.NewLine);
String HTML = new StreamReader(WE.Response.GetResponseStream()).ReadToEnd();
DebugConsole.AppendText(HTML);
return null;
}
String cookieHeader = resp.Headers["Set-cookie"];
if (String.IsNullOrEmpty(cookieHeader))
return null;
else
return cookieHeader;
}
This is actually because the web method requires anti csrf (cross site request forgery, more info here: https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)) validation parameter. What you can do, is to append the csrf value to the request header:
postHeaders.Add("X-CSRFToken", CSRF);
Maybe you can paste your source code here if you need any help with that, so we can look after it
OK! Solution found!
After getting the response of the Log-In site, search in the "Set-cookie" Header for _xsrf. This is the Token you have to put in the header of the next POST request.

How to use WebRequest in c#

I'am trying to use example api call in below link please check link
http://sendloop.com/help/article/api-001/getting-started
My account is "code5" so i tried 2 codes to get systemDate.
1. Code
var request = WebRequest.Create("http://code5.sendloop.com/api/v3/System.SystemDate.Get/json");
request.ContentType = "application/json; charset=utf-8";
string text;
var response = (HttpWebResponse)request.GetResponse();
using (var sr = new StreamReader(response.GetResponseStream()))
{
text = sr.ReadToEnd();
}
2.Code
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create("http://code5.sendloop.com/api/v3/System.SystemDate.Get/json");
httpWebRequest.Method = WebRequestMethods.Http.Get;
httpWebRequest.Accept = "application/json";
But i don't know that i use correctly api by above codes ?
When i use above codes i don't see any data or anything.
How can i get and post api to Sendloop.And how can i use api by using WebRequest ?
I will use api first time in .net so
any help will be appreciated.
Thanks.
It looks like you need to post your API key to the endpoint when making requests. Otherwise, you will not be authenticated and it will return an empty response.
To send a POST request, you will need to do something like this:
var request = WebRequest.Create("http://code5.sendloop.com/api/v3/System.SystemDate.Get/json");
request.ContentType = "application/json; charset=utf-8";
string postData = "APIKey=xxxx-xxxxx-xxxxx-xxxxx-xxxxx";
request.Method = "POST";
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] data = encoding.GetBytes(postData);
request.ContentLength = data.Length;
Stream newStream = request.GetRequestStream(); //open connection
newStream.Write(data, 0, data.Length); // Send the data.
newStream.Close();
string text;
var response = (HttpWebResponse)request.GetResponse();
using (var sr = new StreamReader(response.GetResponseStream()))
{
text = sr.ReadToEnd();
}
string userAuthenticationURI =
"https://maps.googleapis.com/maps/api/distancematrix/json?origins="+ originZip +
"&destinations="+ DestinationZip + "&units=imperial&language=en-
EN&sensor=false&key=Your API Key";
if (!string.IsNullOrEmpty(userAuthenticationURI))
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(userAuthenticationURI);
request.Method = "GET";
request.ContentType = "application/json";
WebResponse response = request.GetResponse();
var responseString = new
StreamReader(response.GetResponseStream()).ReadToEnd();
dynamic obj = JsonConvert.DeserializeObject(responseString);
}

Port webbrowser control, form submit to httpwebrequest?

I would like to port a web browser form submittion to a httpwebrequest one.
its pretty simple:
wb.Document.GetElementsByTagName("input")[0].SetAttribute("value", "image.png");
wb.Document.GetElementsByTagName("input")[1].SetAttribute("value", ImageToBase64(p.Image));
wb.Document.GetElementsByTagName("form")[0].InvokeMember("submit");
I have tried the following, but the image file is currupted somehow...
string param = "name=image.jpg&file=" + ImageToBase64(p.Image);
post(param, "urlToPHPfileShown");
public string post(string param, string url)
{
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
string postArgs = param;
req.Method = "POST";
req.CookieContainer = new CookieContainer();
req.ContentType = #"application/x-www-form-urlencoded";
byte[] buffer = System.Text.ASCIIEncoding.UTF8.GetBytes(postArgs);
req.ContentLength = buffer.Length;
req.AllowAutoRedirect = true;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(buffer, 0, buffer.Length);
reqStream.Close();
}
HttpWebResponse response = (HttpWebResponse)req.GetResponse();
using (Stream respStream = response.GetResponseStream())
{
using (StreamReader sr = new StreamReader(respStream))
{
string s = sr.ReadToEnd();
return s;
}
}
}
EDIT:
I just looked at the post with WireShark.
The one which is working seem to have lots of %2F instead of just / (slash).
So is there maybe a charset problem?

C# Xml in Http Post Request Message Body

I am looking for an example of how, in C#, to put a xml document in the message body of a http request and then parse the response. I've read the documentation but I would just like to see an example if there's one available. Does anyone have a example?
thanks
private static string WebRequestPostData(string url, string postData)
{
System.Net.WebRequest req = System.Net.WebRequest.Create(url);
req.ContentType = "text/xml";
req.Method = "POST";
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(postData);
req.ContentLength = bytes.Length;
using (Stream os = req.GetRequestStream())
{
os.Write(bytes, 0, bytes.Length);
}
using (System.Net.WebResponse resp = req.GetResponse())
{
if (resp == null) return null;
using (System.IO.StreamReader sr = new System.IO.StreamReader(resp.GetResponseStream()))
{
return sr.ReadToEnd().Trim();
}
}
}
You should use the WebRequest class.
There is an annotated sample available here to send data:
http://msdn.microsoft.com/en-us/library/debx8sh9.aspx

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