Develop Reference

C# WebClient receives 403 when getting html from a site

I am trying to download the HTML from a site and parse it. I am actually interested in the OpenGraph data in the head section only. For most sites using the WebClient, HttpClient or HtmlAgilityPack works, but some domains I get 403, for example: westelm.com
I have tried setting up the Headers to be absolutely the same as they are when I use the browser, but I still get 403. Here is some code:
string url = "https://www.westelm.com/m/products/brushed-herringbone-throw-t5792/?";
var doc = new HtmlDocument();
using(WebClient client = new WebClient()) {
client.Headers["User-Agent"] = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Safari/537.36";
client.Headers["Accept"] = "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9";
client.Headers["Accept-Encoding"] = "gzip, deflate, br";
client.Headers["Accept-Language"] = "en-US,en;q=0.9";
doc.Load(client.OpenRead(url));
}
At this point, I am getting a 403.
Am I missing something or the site administrator is protecting the site from API requests?
How can I make this work? Is there a better way to get OpenGraph data from a site?
Thanks.

I used your question to resolve the same problem. IDK if you're already fixed this but I tell you how it worked for me
A page was giving me 403 for the same reasons. The thing is: you need to emulate a "web browser" from the code, sending a lot of headers.
I used one of yours headers I wasn't using (like Accept-Language)
I didn't use WebClient though, I used HttpClient to parse the webpage
private static async Task<string> GetHtmlResponseAsync(HttpClient httpClient, string url)
{
using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(url));
request.Headers.TryAddWithoutValidation("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9");
request.Headers.TryAddWithoutValidation("Accept-Encoding", "gzip, deflate, br");
request.Headers.TryAddWithoutValidation("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Safari/537.36");
request.Headers.TryAddWithoutValidation("Accept-Charset", "UTF-8");
request.Headers.TryAddWithoutValidation("Accept-Language", "en-US,en;q=0.9");
using var response = await httpClient.SendAsync(request).ConfigureAwait(false);
if (response == null)
return string.Empty;
using var responseStream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false);
using var decompressedStream = new GZipStream(responseStream, CompressionMode.Decompress);
using var streamReader = new StreamReader(decompressedStream);
return await streamReader.ReadToEndAsync().ConfigureAwait(false);
}
If it helps you, I'm glad. If not, I will leave this answer here to help someone else in the future!

How can I call a web api in c# using HttpClient?

So I am trying to call a api in my C# method and am not getting the response that I would be getting, if I called the api using postman or insomia.
public static async Task GetObject()
{
var httpClient = new HttpClient();
//var t = await httpClient.GetStringAsync("https://ipapi.co/json/");
var y = await httpClient.GetAsync("https://ipapi.co/json/");
var o = await y.Content.ReadAsStringAsync();
var j = y.Content.ReadAsStringAsync();
}
The api is getting my request but its not returning the right result. You should be getting this result. Click on this https://ipapi.co/json/
What am getting is this
{
"error":true,
"reason":"RateLimited",
"message":"Sign up for IP Address Location API # https://ipapi.co"
}
But I don't get it, when am using postman

You need to add the user-agent header.
httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.202 Safari/535.1");

Better to Use xNet.dll or Leaf.xNet.dll libraries
Or restsharp one
Google them
I'm also new If ur interesting to contact me
Discord Cyx.#4260

Why can't I use HttpClient to log in to this ASP.NET website?

There's an ASP.NET website from a third party that requires one to log on. I need to get some data from the website and parse it, so I figured I'd use HttpClient to post the necessary credentials to the website, same as the browser would do it. Then, after that POST request, I figured I'd be able to use the cookie values I received to make further request to the (authorization-only) urls.
I'm down to the point where I can successfully POST the credentials to the login url and receive three cookies: ASP.NET_SessionId, .ASPXAUTH, and a custom value used by the website itself, each with their own values. I figured that since the HttpClient I set up is using an HttpHandler that is using a CookieContainer, the cookies would be sent along with each further request, and I'd remain logged in.
However, this does not appear to be working. If I use the same HttpClient instance to then request one of the secured areas of the website, I'm just getting the login form again.
The code:
const string loginUri = "https://some.website/login";
var cookieContainer = new CookieContainer();
var clientHandler = new HttpClientHandler() { CookieContainer = cookieContainer, AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate };
var client = new HttpClient(clientHandler);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
var loginRequest = new HttpRequestMessage(HttpMethod.Post, loginUri);
// These form values correspond with the values posted by the browser
var formContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair<string, string>("customercode", "password"),
new KeyValuePair<string, string>("customerid", "username"),
new KeyValuePair<string, string>("HandleForm", "Login")
});
loginRequest.Content = formContent;
loginRequest.Headers.UserAgent.ParseAdd("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393");
loginRequest.Headers.Referrer = new Uri("https://some.website/Login?ReturnUrl=%2f");
loginRequest.Headers.Host = "some.website";
loginRequest.Headers.Connection.Add("Keep-Alive");
loginRequest.Headers.CacheControl = new System.Net.Http.Headers.CacheControlHeaderValue() { NoCache = true };
loginRequest.Headers.AcceptLanguage.ParseAdd("nl-NL");
loginRequest.Headers.AcceptEncoding.ParseAdd("gzip, deflate");
loginRequest.Headers.Accept.ParseAdd("text/html, application/xhtml+xml, image/jxr, */*");
var response = await client.SendAsync(loginRequest);
var responseString = await response.Content.ReadAsStringAsync();
var cookies = cookieContainer.GetCookies(new Uri(loginUri));
When using the proper credentials, cookies contains three items, including a .ASPXAUTH cookie and a session id, which suggests that the login succeeded. However:
var text = await client.GetStringAsync("https://some.website/secureaction");
...this just returns the login form again, and not the content I get when I log in using the browser and navigate to /secureaction.
What am I missing?
EDIT: here's the complete request my application is making and the request chrome is making. They are identical, save for the cookie values. I ran them through windiff: the lines marked <! are the lines sent by my application, the ones marked !> are sent by Chrome.
GET https://some.website/secureaction
Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36
Accept-Encoding: gzip, deflate, sdch, br
Upgrade-Insecure-Requests: 1
Host: some.website
Accept-Language:nl-NL,
>> nl;q=0.8,en-US;q=0.6,en;q=0.4
Accept: text/html,
>> application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Cookie:
<! customCookie=7CF190C0;
<! .ASPXAUTH=37D61E47(shortened for readability);
<! ASP.NET_SessionId=oqwmfwahpvf0qzpiextx0wtb
!> ASP.NET_SessionId=kn4t4rmeu2lfrgozjjga0z2j;
!> customCookie=8D43E263;
!> .ASPXAUTH=C2477BA1(shortened for readability)
The HttpClient application get a 302 referral to /login, Chrome gets a 200 response containing the requested page.

As requested, here's how I eventually made it work. I had to do a simple GET request to /login first, and then do a POST with the login credentials. I don't recall what value exactly is being set by that GET (I assume a cookie with some encoded value the server wants), but the HttpClient takes care of the cookies anyway, so it just works. Here's the final, working code:
const string loginUri = "https://some.website/login";
var cookieContainer = new CookieContainer();
var clientHandler = new HttpClientHandler()
{
CookieContainer = cookieContainer,
AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate
};
var client = new HttpClient(clientHandler);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
// First do a GET to the login page, allowing the server to set certain
// required cookie values.
var initialGetRequest = new HttpRequestMessage(HttpMethod.GET, loginUri);
await client.SendAsync(initialGetRequest);
var loginRequest = new HttpRequestMessage(HttpMethod.Post, loginUri);
// These form values correspond with the values posted by the browser
var formContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair<string, string>("customercode", "password"),
new KeyValuePair<string, string>("customerid", "username"),
new KeyValuePair<string, string>("HandleForm", "Login")
});
loginRequest.Content = formContent;
loginRequest.Headers.UserAgent.ParseAdd("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393");
loginRequest.Headers.Referrer = new Uri("https://some.website/Login?ReturnUrl=%2f");
loginRequest.Headers.Host = "some.website";
loginRequest.Headers.Connection.Add("Keep-Alive");
loginRequest.Headers.CacheControl = new System.Net.Http.Headers.CacheControlHeaderValue() { NoCache = true };
loginRequest.Headers.AcceptLanguage.ParseAdd("nl-NL");
loginRequest.Headers.AcceptEncoding.ParseAdd("gzip, deflate");
loginRequest.Headers.Accept.ParseAdd("text/html, application/xhtml+xml, image/jxr, */*");
var response = await client.SendAsync(loginRequest);
var responseString = await response.Content.ReadAsStringAsync();
var cookies = cookieContainer.GetCookies(new Uri(loginUri));

Windows store app Post with multipartFormDataContent

I`m porting Android java App to C#, Windows store app. it must send POST to server with multipart content, image and some key/value data.
java code:
HttpPost post = new HttpPost(SERVER);
MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
entity.addPart(filename, new ByteArrayBody(byteArray, "image/jpeg", filename + ".jpg"));
entity.addPart("usr", new StringBody(user));
entity.addPart("sid", new StringBody(session));
entity.addPart("action", new StringBody(method));
post.setEntity(entity);
and Windows Store code:
MultipartFormDataContent multipartContent = new MultipartFormDataContent();
ByteArrayContent byteContent = new ByteArrayContent(byteArray);
multipartContent.Add(byteContent, fileName);
multipartContent.Add(new StringContent(User), "usr");
multipartContent.Add(new StringContent(Session), "sid");
multipartContent.Add(new StringContent(method), "action");
But server respond with differend responses. What could it be?

If the server determines output by user-agent, then try setting same UserAgent on both Apps.
http://developer.android.com/reference/android/net/http/AndroidHttpClient.html
// UserAgent taken from http://www.useragentstring.com/pages/Android%20Webkit%20Browser/
// Pick one you find suitable or use Firefox/Chrome UserAgents, whatever works for you
String userAgent = "Mozilla/5.0 (Linux; U; Android 2.3.4; fr-fr; HTC Desire Build/GRJ22) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1";
AndroidHttpClient httpClient = AndroidHttpClient.getInstance(userAgent);
httpClient.execute(post);
C#/.NET
// make sure to use same user agent in both apps
string userAgent = "Mozilla/5.0 (Linux; U; Android 2.3.4; fr-fr; HTC Desire Build/GRJ22) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1";
HttpClient httpClient = new HttpClient();
httpClient.DefaultRequestHeaders.Add("user-agent",userAgent);
That should give you same results, if the server returns different results based on user-agent header.

Mediaelement C# Windows 8 store get song/artist online radiostream

I need some help on how to read taginfo (song/artist) from a online radiostream. I'm building my app in c# and I use the mediaelement.
When I play this steam in windows media player/winamp it show the current playing song.
I have tried the MarkerReached event, but nothing happens.
Here is the code I tried. I can't get it working.
string responseBodyAsText;
textblock.Text = "Click...";
Uri apiurl = new Uri("http://streamurl");
// create request
HttpClient client2 = new HttpClient();
client2.MaxResponseContentBufferSize = 2560;
client2.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36");
client2.DefaultRequestHeaders.Add("GET", "/"+apiurl.ToString()+ " HTTP/1.0");
client2.DefaultRequestHeaders.Add("Icy-MetaData", "1");
HttpResponseMessage response2 = await client2.GetAsync(apiurl);
//response2.EnsureSuccessStatusCode();
responseBodyAsText = await response2.Content.ReadAsStringAsync();
textblock.Text = responseBodyAsText.ToString();