Develop Reference

C# HTTP Post request from a chatbot in MS Bot Framework

I am a very novice C# person so please dont be too hard on me
Im trying to make a post request to MSFLOW from a MSBOT Framwork chatbot. The post request triggers the flow to send an email to chatbot users manager.
I just dont know where to start. I have a basic BOT template from Az but how and where should I put the request
Many thanks

use HttpWebRequest
here is an example of using Http POST request .
using System;
using System.IO;
using System.Net;
using System.Text;
namespace Examples.System.Net
{
public class WebRequestPostExample
{
public static void Main()
{
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create("http://www.example.com/post");
// Set the Method property of the request to POST.
request.Method = "POST";
// Create POST data and convert it to a byte array.
string postData = "This is a test that posts this string to a Web server.";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream();
// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close();
// Get the response.
WebResponse response = request.GetResponse();
// Display the status.
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd();
// Display the content.
Console.WriteLine(responseFromServer);
// Clean up the streams.
reader.Close();
dataStream.Close();
response.Close();
}
}
}

First, the Flow needs an Request - When an HTTP request is received trigger: https://learn.microsoft.com/en-us/azure/connectors/connectors-native-reqres The trigger can be fired by calling it with any rest client: https://flow.microsoft.com/fr-fr/blog/call-flow-restapi/
Most likely, the bot will make the call to the HTTP Request Trigger when the bot is messaged something specific by a user. Notice the BasicBot.cs file has an OnTurnAsync method. Within here, you can check the .Text property of the activity and if it is "send email" then call the Flow Trigger:
if (activity.Type == ActivityTypes.Message)
{
if(active.Text == "send email")
{
await SendEmail();
}
else
{
// other BasicBot.cs code
}
...
As demonstrated by M.zK, you can use WebRequest in C# to make the Flow Trigger call. You can also use HttpClient:
using (var request = new HttpRequestMessage(HttpMethod.Post, "https://prod-13.westus.logic.azure.com:443/workflows/etc"))
{
var content = new { Properties = new { Property1 = "property 1 value", Property2 = "Property 2 value" } };
var json = JsonConvert.SerializeObject(content);
request.Content = new StringContent(json, Encoding.UTF8, "application/json");
using (var client = new HttpClient())
{
await client.SendAsync(request).ConfigureAwait(false);
}
}

web request in asp.net core

I want to do a web request in a asp.net core project. I tried the following but it doesn't seem to send the data in the request:
using System.Net;
...
//encoder
UTF8Encoding enc = new UTF8Encoding();
//data
string data = "[\"some.data\"]";
//Create request
WebRequest request = WebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/json";
request.Credentials = new NetworkCredential(user, secret);
//Set data in request
Stream dataStream = await request.GetRequestStreamAsync();
dataStream.Write(enc.GetBytes(data), 0, data.Length);
//Get the response
WebResponse wr = await request.GetResponseAsync();
Stream receiveStream = wr.GetResponseStream();
StreamReader reader = new StreamReader(receiveStream, Encoding.UTF8);
string content = reader.ReadToEnd();
I don't get an error, the request was send but it doesn't seem to send the data with the request.
I also can't give the length of the data with the request. Is this a core issue? (ps: The credentials are send correctly)
Can anyone help me?

You may be facing a synchronization context problem.
Try to await the asynchronous methods like GetRequestStreamAsync() and GetResponseAsync() instead of getting the Result property.
//Set data in request
Stream dataStream = await request.GetRequestStreamAsync();
//Get the response
WebResponse wr = await request.GetResponseAsync();

Finally solved it. There was a bug in my external API code where I resolved the API request. The code in my question works (If someone wants to use it).
PS: I edit the code with the remark of ycrumeyrolle

Proper Way to open this URL in a C# app

I have a URL that I want to open in my C# app. This URL is used to talk to a communications device, not an internet web site. I have gotten by (I think) all the cert stuff. But the text I get back in the program IS NOT the same thing that CORRECTLY displays when I use a web browser.
Here's the code.
using System;
using System.IO;
using System.Net;
using System.Text;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Web;
namespace VMLConnStatus
{
class Program
{
static void Main(string[] args)
{
System.Net.ServicePointManager.CertificatePolicy = new MyPolicy();
// Create a request for the URL: https://192.168.30.15/cgi-bin/connstatus?202
String url = "https://192.168.30.15/cgi-bin/";
String data = "connstatus?202";
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create(url);
// Set the Method property of the request to POST.
request.Method = "POST";
// Create POST data and convert it to a byte array.
string postData = data;
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream();
// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close();
// Get the response.
WebResponse response = request.GetResponse();
// Display the status.
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd();
// Display the content.
Console.WriteLine(responseFromServer);
// Clean up the streams.
reader.Close();
dataStream.Close();
response.Close();
Console.ReadLine();
}
}
public class MyPolicy : ICertificatePolicy
{
public bool CheckValidationResult(ServicePoint srvPoint,
X509Certificate certificate, WebRequest request,
int certificateProblem)
{
//Return True to force the certificate to be accepted.
return true;
}
}
}
The result, though not perfectly displayed in Chrome, should be:
NA NA NA NA 4c:cc:34:02:6d:26 00:23:A7:24:A3:B6
But the text I get in the console window is:
Ok
<HTML>
<HEAD><TITLE>Index of cgi-bin/</TITLE></HEAD>
<BODY BGCOLOR="#99cc99" TEXT="#000000" LINK="#2020ff" VLINK="#4040cc">
<H4>Index of cgi-bin/</H4>
<PRE>
. 15Jun2014 09:48
0
.. 15Jun2014 09:48
0
connstatus 15Jun2014 09:48
19580
firmwarecfg 15Jun2014 09:48
45736
webcm 15Jun2014 09:48
23836
</PRE>
<HR>
<ADDRESS><A HREF="http://www.acme.com/software/mini_httpd/">mini_httpd/1.19 19de
c2003</A></ADDRESS>
</BODY>
</HTML>
Not EVEN close to the same thing.
What am I doing wrong?
Chuck
UPDATE: Code changed. URL, GET, and request writing (presuming I understood the directions). New code is:
static void Main(string[] args)
{
System.Net.ServicePointManager.CertificatePolicy = new MyPolicy();
// Create a request for the URL: https://192.168.30.15/cgi-bin/connstatus?202
String url = "https://192.168.30.15/cgi-bin/connstatus?202";
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create(url);
// Set the Method property of the request to POST.
request.Method = "GET";
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Get the request stream.
//Now it throws an exception here--------------------------------
//"Cannot send a content-body with this verb-type."
Stream dataStream = request.GetRequestStream();
// Close the Stream object.
dataStream.Close();
// Get the response.
WebResponse response = request.GetResponse();
// Display the status.
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd();
// Display the content.
Console.WriteLine(responseFromServer);
// Clean up the streams.
reader.Close();
dataStream.Close();
response.Close();
Console.ReadLine();
}

You are using http method POST but the url you have in the comment looks more like GET so then you probably need WebRequest.Create(url + data).
The incorrect response is the index page for https://192.168.30.15/cgi-bin/ which if you put into Chrome will give you the same "wrong" response.
You might not need to write any data to the request stream and can change the Method and ContentType for the request.

The solution required two parts.
First, doing the proper things, thus a total code rework.
I had the dreaded "The server committed a protocol violation. Section=ResponseHeader Detail=Header name is invalid". I tried to make the programatic solution for this work, but it is a .NET 2.0 solution and I was not able to figure it out in .NET4+. So, I edited the .config file and went on.
Here's the final code:
//Initialization
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(#"https://192.168.30.15/cgi-bin/connstatus?202");
//method is GET.
WebReq.Method = "GET";
//Get the response handle
HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
//read the response
Stream Answer = WebResp.GetResponseStream();
StreamReader _Answer = new StreamReader(Answer);
//display it
Console.WriteLine(_Answer.ReadToEnd());
//pause for the ENTER key
Console.ReadLine();
This was added to the .config file in the debug folder (and would be added in the Release folder also..... using VS2013)
<system.net>
<settings>
<httpWebRequest useUnsafeHeaderParsing = "true"/>
</settings>
</system.net>
Thank-you to everyone that replied. The inspiration helped me get to the solution.

Getting the Redirected URLs from the Original URL [duplicate]

Using the WebClient class I can get the title of a website easily enough:
WebClient x = new WebClient();
string source = x.DownloadString(s);
string title = Regex.Match(source,
#"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>",
RegexOptions.IgnoreCase).Groups["Title"].Value;
I want to store the URL and the page title. However when following a link such as:
http://tinyurl.com/dbysxp
I'm clearly going to want to get the Url I'm redirected to.
QUESTIONS
Is there a way to do this using the WebClient class?
How would I do it using HttpResponse and HttpRequest?

If I understand the question, it's much easier than people are saying - if you want to let WebClient do all the nuts and bolts of the request (including the redirection), but then get the actual response URI at the end, you can subclass WebClient like this:
class MyWebClient : WebClient
{
Uri _responseUri;
public Uri ResponseUri
{
get { return _responseUri; }
}
protected override WebResponse GetWebResponse(WebRequest request)
{
WebResponse response = base.GetWebResponse(request);
_responseUri = response.ResponseUri;
return response;
}
}
Just use MyWebClient everywhere you would have used WebClient. After you've made whatever WebClient call you needed to do, then you can just use ResponseUri to get the actual redirected URI. You'd need to add a similar override for GetWebResponse(WebRequest request, IAsyncResult result) too, if you were using the async stuff.

I know this is already an answered question, but this works pretty to me:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://tinyurl.com/dbysxp");
request.AllowAutoRedirect = false;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string redirUrl = response.Headers["Location"];
response.Close();
//Show the redirected url
MessageBox.Show("You're being redirected to: "+redirUrl);
Cheers.! ;)

With an HttpWebRequest, you would set the AllowAutoRedirect property to false. When this happens, any response with a status code between 300-399 will not be automatically redirected.
You can then get the new url from the response headers and then create a new HttpWebRequest instance to the new url.
With the WebClient class, I doubt you can change it out-of-the-box so that it does not allow redirects. What you could do is derive a class from the WebClient class and then override the GetWebRequest and the GetWebResponse methods to alter the WebRequest/WebResponse instances that the base implementation returns; if it is an HttpWebRequest, then set the AllowAutoRedirect property to false. On the response, if the status code is in the range of 300-399, then issue a new request.
However, I don't know that you can issue a new request from within the GetWebRequest/GetWebResponse methods, so it might be better to just have a loop that executes with HttpWebRequest/HttpWebResponse until all the redirects are followed.

I got the Uri for the redirected page and the page contents.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(strUrl);
request.AllowAutoRedirect = true;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream dataStream = response.GetResponseStream();
strLastRedirect = response.ResponseUri.ToString();
StreamReader reader = new StreamReader(dataStream);
string strResponse = reader.ReadToEnd();
response.Close();

In case you are only interested in the redirect URI you can use this code:
public static string GetRedirectUrl(string url)
{
HttpWebRequest request = (HttpWebRequest) HttpWebRequest.Create(url);
request.AllowAutoRedirect = false;
using (HttpWebResponse response = HttpWebResponse)request.GetResponse())
{
return response.Headers["Location"];
}
}
The method will return
null - in case of no redirect
a relative url - in case of a redirect
Please note: The using statement (or a final response.close()) is essential. See MSDN Library for details. Otherwise you may run out of connections or get a timeout when executing this code multiple times.

HttpWebRequest.AllowAutoRedirect can be set to false. Then you'd have to manually http status codes in the 300 range.
// Create a new HttpWebRequest Object to the mentioned URL.
HttpWebRequest myHttpWebRequest=(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest.MaximumAutomaticRedirections=1;
myHttpWebRequest.AllowAutoRedirect=true;
HttpWebResponse myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();

The WebClient class has an option to follow redirects. Set that option and you should be fine.

Ok this is really hackish, but the key is to use the HttpWebRequest and then set the AllowAutoRedirect property to true.
Here's a VERY hacked together example
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://tinyurl.com/dbysxp");
req.Method = "GET";
req.AllowAutoRedirect = true;
WebResponse response = req.GetResponse();
response.GetResponseStream();
Stream responseStream = response.GetResponseStream();
// Content-Length header is not trustable, but makes a good hint.
// Responses longer than int size will throw an exception here!
int length = (int)response.ContentLength;
const int bufSizeMax = 65536; // max read buffer size conserves memory
const int bufSizeMin = 8192; // min size prevents numerous small reads
// Use Content-Length if between bufSizeMax and bufSizeMin
int bufSize = bufSizeMin;
if (length > bufSize)
bufSize = length > bufSizeMax ? bufSizeMax : length;
StringBuilder sb;
// Allocate buffer and StringBuilder for reading response
byte[] buf = new byte[bufSize];
sb = new StringBuilder(bufSize);
// Read response stream until end
while ((length = responseStream.Read(buf, 0, buf.Length)) != 0)
sb.Append(Encoding.UTF8.GetString(buf, 0, length));
string source = sb.ToString();string title = Regex.Match(source,
#"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>",RegexOptions.IgnoreCase).Groups["Title"].Value;
enter code here

HTTP POST in .NET doesn't work

I've got a problem with creating an HTTP post request in .NET. When I do this request in ruby it does work.
When doing the request in .NET I get following error:
<h1>FOXISAPI call failed</h1><p><b>Progid is:</b> carejobs.carejobs
<p><b>Method is:</b> importvacature/
<p><b>Parameters are:</b>
<p><b> parameters are:</b> vacature.deelnemernr=478
</b><p><b>GetIDsOfNames failed with err code 80020006: Unknown name.
</b>
Does anyone knows how to fix this?
Ruby:
require 'net/http'
url = URI.parse('http://www.carejobs.be/scripts/foxisapi.dll/carejobs.carejobs.importvacature')
post_args = {
'vacature.deelnemernr' => '478',
}
resp, data = Net::HTTP.post_form(url, post_args)
print resp
print data
C#:
Uri address = new Uri(url);
// Create the web request
HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;
// Set type to POST
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
// Create the data we want to send
StringBuilder data = new StringBuilder();
data.Append("vacature.deelnemernr=" + HttpUtility.UrlEncode("478"));
// Create a byte array of the data we want to send
byte[] byteData = UTF8Encoding.UTF8.GetBytes(data.ToString());
// Set the content length in the request headers
request.ContentLength = byteData.Length;
// Write data
using (Stream postStream = request.GetRequestStream())
{
postStream.Write(byteData, 0, byteData.Length);
}
// Get response
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
// Get the response stream
StreamReader reader = new StreamReader(response.GetResponseStream());
// Console application output
result = reader.ReadToEnd();
}
return result;

Don't you need the ? after the URL in order to do a post with parameters? I think that Ruby hides this behind the scenes.

I found the problem! The url variable in the C# code was "http://www.carejobs.be/scripts/foxisapi.dll/carejobs.carejobs.importvacature/"
It had to be "http://www.carejobs.be/scripts/foxisapi.dll/carejobs.carejobs.importvacature" without the backslash.