I have a silverlight application which calls a web page, on clikc of a button. I want to send some parameters to the page on click of the button.
Now I can send it via query string but I don't want to do it as I might want to send a list of users which can go lenghty.
Also using sessions is not an option as these are two different applications. Also on click of the button we have to do some operations and display the results in the web page.
Is there a way I can call the web method in the page - Do my operation and then then show the details of the operation on my web page.
Maybe you could use something like the WebRequest class to create a POST request and then use the HttpWebResponse to get the details.
var request = (HttpWebRequest) WebRequest.Create(Uri);
request.Method = "POST";
var postData = string.Format("param1={0}¶m2={1}", "value1", "value2");
var data = Encoding.UTF8.GetBytes(postData);
request.ContentLength = data.Length;
var requestStream = request.GetRequestStream();
requestStream.Write(data, 0, data.Length);
requestStream.Close();
var response = request.GetResponse() as HttpWebResponse;
Related
I am working on getting information that is behind a log in page, and using this as my starting point.
Looking at the Network tab, I looked at the form data and saw there were 3 additional values than just client/password (csrf, time, hash).
I attempted to log into the site as follows.
string formUrl = "mysite_loginaction";
string formParams = string.Format("client_id={0}&password={1}", "client", "password");
string cookieHeader;
WebRequest req = WebRequest.Create(formUrl);
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
byte[] bytes = Encoding.ASCII.GetBytes(formParams);
req.ContentLength = bytes.Length;
using (Stream os = req.GetRequestStream())
{
os.Write(bytes, 0, bytes.Length);
}
WebResponse resp = req.GetResponse();
cookieHeader = resp.Headers["Set-cookie"];
When I print out the resp to my console, it shows my the log in page, when i was expecting the next page after login (google 2f page).
Do I need to post a csfr, time, and hash values as well to get a successful login?
Like it has been mentioned in your link, there is a concept of sessionid token. If you do want to stay logged in, you need to pass that token everytime for the following http requests.
Also, the CSRF token will always be different each time you do the request, but you do need to pass it along your next request to be successful.
To know more about CSRF, I should redirect you to this link
You're going to have to mess around with it. Most of the time you don't need all the headers, but I would assume that hash is required.
how would I be able to do something like http://myanimelist.net/modules.php?go=api#verifycred
aka "curl -u user:password http://myanimelist.net/api/account/verify_credentials.xml"
I wish to option the id
my code so far is
string url = "http://myanimelist.net/api/account/verify_credentials.xml";
WebRequest request = WebRequest.Create(url);
request.ContentType = "xml";
request.Method = "GET";
request.Credentials = new NetworkCredential(username, password);
byte[] buffer = Encoding.GetEncoding("UTF-8").GetBytes("xml/user/id"); // i think this line?
Stream reqstr = request.GetRequestStream();
reqstr.Write(buffer, 0, buffer.Length);
reqstr.Close();
but I get a error on "reqstr.Write(buffer, 0, buffer.Length)"
Cannot send a content-body with this verb-type, I have tried googling but with no prevail, I am using c#
Your snippet is trying to send a GET request with request data (you're calling GetRequestStream and then writing some data to the request stream). The HTTP protocol does not allow this - you can only send data with POST request.
However, the API that you are trying to call is actually doing something different - you do not need to send it the XML data. The XML data (with user ID and user name) is the response that you get when you successfully login.
So, instead of calling GetRequestStream and writing the XML data, you need to call GetResponse and then GetResponseStream to read the XML data!
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
Say I am building a c# application.
The purpose of application to :
get username & password from user.
and show some information present on the website.
in the background, after taking username and password, it should :
log in to a website with those credentials.
and click on the anchor link that appears after logging in.
find out the span that hold the info.
get the info.
that was an example. I am actually building an app to show bandwidth usage information.
The server does not expose any API for that.
Is there any tutorial/info/article available for similar purpose ? I just don't what to search for ?
Basic Introduction To HttpWebRequests
Firstly, you're going to need the right tools for the job. Go and download the Live HTTP Headers plugin for Firefox. This will allow you to view HTTP headers in real time so you can view the POST data that is sent when you interact with the website. Once you know the data that is sent to the website you can emulate the process by creating your own HTTP web requests programmatically. Tool > Live HTTP Headers
Load Live HTTP Headers by navigating to Tools > Live HTTP Headers. Once you've loaded the GUI navigate to the website you wish to login to, I will use Facebook for demonstration purposes. Type in your credentials ready to login, but before you do Clear the GUI text window and ensure that the check box labeled Capture is checked. Once you hit login you will see the text window flood with various information about the requests including the POST data which you need.
I find it best to click Save All... and then search for your username in the text document so that you can identify the POST data easily. For my request the POST data looked like this:
lsd=AVp-UAbD&display=&legacy_return=1&return_session=0&trynum=1&charset_test=%E2%82%AC%2C%C2%B4%2C%E2%82%AC%2C%C2%B4%2C%E6%B0%B4%2C%D0%94%2C%D0%84&timezone=0&lgnrnd=214119_mDgc&lgnjs=1356154880&email=%myfacebookemail40outlook.com&pass=myfacebookpassword&default_persistent=0
Which can then be defined in C# like so:
StringBuilder postData = new StringBuilder();
postData.Append("lsd=AVqRGVie&display=");
postData.Append("&legacy_return=1");
postData.Append("&return_session=0");
postData.Append("&trynum=1");
postData.Append("&charset_test=%E2%82%AC%2C%C2%B4%2C%E2%82%AC%2C%C2%B4%2C%E6%B0%B4%2C%D0%94%2C%D0%84");
postData.Append("&timezone=0");
postData.Append("&lgnrnd=153743_eO6D");
postData.Append("&lgnjs=1355614667");
postData.Append(String.Format("&email={0}", "CUSTOM_EMAIL"));
postData.Append(String.Format("&pass={0}", "CUSTOM_PASSWORD"));
postData.Append("&default_persistent=0");
I'm aiming to show you the relation between the POST data that we can send 'manually' via the web browser and how we can use said data to emulate the request in C#. Understand that sending POST data is far from deterministic. Different websites work in different ways and can throw all kinds of things your way. Below is a function I put together to validate that Facebook credentials are correct. I can't and shouldn't go into extraordinary depth here as the classes and their members are well self-documented. You can find better information than I can offer about the methods used at MSDN for example, WebRequest.Method Property
private bool ValidateFacebookCredentials(string email, string password)
{
CookieContainer cookies = new CookieContainer();
HttpWebRequest request = null;
HttpWebResponse response = null;
string returnData = string.Empty;
//Need to retrieve cookies first
request = (HttpWebRequest)WebRequest.Create(new Uri("https://www.facebook.com/login.php?login_attempt=1"));
request.Method = "GET";
request.CookieContainer = cookies;
response = (HttpWebResponse)request.GetResponse();
//Set up the request
request = (HttpWebRequest)WebRequest.Create(new Uri("https://www.facebook.com/login.php?login_attempt=1"));
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13";
request.Referer = "https://www.facebook.com/login.php?login_attempt=1";
request.AllowAutoRedirect = true;
request.KeepAlive = true;
request.CookieContainer = cookies;
//Format the POST data
StringBuilder postData = new StringBuilder();
postData.Append("lsd=AVqRGVie&display=");
postData.Append("&legacy_return=1");
postData.Append("&return_session=0");
postData.Append("&trynum=1");
postData.Append("&charset_test=%E2%82%AC%2C%C2%B4%2C%E2%82%AC%2C%C2%B4%2C%E6%B0%B4%2C%D0%94%2C%D0%84");
postData.Append("&timezone=0");
postData.Append("&lgnrnd=153743_eO6D");
postData.Append("&lgnjs=1355614667");
postData.Append(String.Format("&email={0}", email));
postData.Append(String.Format("&pass={0}", password));
postData.Append("&default_persistent=0");
//write the POST data to the stream
using(StreamWriter writer = new StreamWriter(request.GetRequestStream()))
writer.Write(postData.ToString());
response = (HttpWebResponse)request.GetResponse();
//Read the web page (HTML) that we retrieve after sending the request
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
returnData = reader.ReadToEnd();
return !returnData.Contains("Please re-enter your password");
}
Sample Code on Grabbing Contents (Screen Scraping)
Uri uri = new Uri("http://www.microsoft.com/default.aspx");
if(uri.Scheme = Uri.UriSchemeHttp)
{
HttpWebRequest request = HttpWebRequest.Create(uri);
request.Method = WebRequestMethods.Http.Get;
HttpWebResponse response = request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string tmp = reader.ReadToEnd();
response.Close();
Response.Write(tmp);
}
Sample Code on how to Post Data to remote Web Page using HttpWebRequest
Uri uri = new Uri("http://www.amazon.com/exec/obidos/search-handle-form/102-5194535-6807312");
string data = "field-keywords=ASP.NET 2.0";
if (uri.Scheme == Uri.UriSchemeHttp)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);
request.Method = WebRequestMethods.Http.Post;
request.ContentLength = data.Length;
request.ContentType = "application/x-www-form-urlencoded";
StreamWriter writer = new StreamWriter(request.GetRequestStream());
writer.Write(data);
writer.Close();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string tmp = reader.ReadToEnd();
response.Close();
Response.Write(tmp);
}
Source
Any HTTP client implementation, there are tons of open-source libraries for that. look at curl for example. Some dude made a .NET wrapper for it.
You can continue using WebClient to POST (instead of GET, which is the HTTP verb you're currently using with DownloadString), but I think you'll find it easier to work with the (slightly) lower-level classes WebRequest and WebResponse.
There are two parts to this - the first is to post the login form, the second is recovering the "Set-cookie" header and sending that back to the server as "Cookie" along with your GET request. The server will use this cookie to identify you from now on (assuming it's using cookie-based authentication which I'm fairly confident it is as that page returns a Set-cookie header which includes "PHPSESSID").
Click Here to Check in Detail
We were initially submitting login credentials via a form. Now we're trying to mimic the same behavior by using C# to programmatically submit the same login creds via HTTP POST using HttpWebRequest.
We know that we're sending in the data correctly, and that the web service is receiving and authenticating the login data smoothly.
The problem, however, is that when we're using the form for login, the web service automatically redirects the user on success. We can't seem to duplicate that somehow when using an HttpWebRequest because the user and the request exist on two different sessions (I think).
How should I perform the redirect behavior on successful authentication when using HttpWebRequest? When we redirect manually, we're treated as if we're not authenticated.
For point of illustration, my request code looks similar to the following:
// var data = some byte[] data
var request =
(HttpWebRequest)WebRequest.Create("http://domain.com/login.asp");
request.ContentType = "x-www-form-urlencoded";
request.ContentLength = data.Length;
request.Method = "POST";
using (var stream = request.GetRequestStream()) {
stream.Write(data, 0, data.Length);
stream.Close();
}
var response = (HttpWebResponse)request.GetResponse();
I'm laying this out as an ASP.NET MVC 3 project, so this code more or less appears in a controller action.
I need to post data to a website. So I created a small app in C#.net where I open this website and fill in all the controls (radio buttons, text boxes, checkboxes etc) with the values from my database. I also have a click event on the SUBMIT button. The app then waits for 10-15 seconds and then copies the response from the webpage to my database.
As you can see, this is really a hectic process. If there are thousands of records to upload, this app takes much longer (due to fact that it waits 15s for the response).
Is there any other way to post data? I am looking for something like concatenating all the fields with its value and uploading it like a stream of data. How will this work if the website is https and not http?
You can use HttpWebRequest to do this, and you can concatenate all the values you want to post into a single string for the request. It could look something like this:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.yoursite.com");
request.Method = "POST";
formContent = "FormValue1=" + someValue +
"&FormValue2=" + someValue2 +
"&FormValue=" + someValue2;
byte[] byteArray = Encoding.UTF8.GetBytes(formContent);
request.ContentType = "application/x-www-form-urlencoded";
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 = HttpUtility.UrlDecode(reader.ReadToEnd());
//You may need HttpUtility.HtmlDecode depending on the response
reader.Close();
dataStream.Close();
response.Close();
This method should work fine for http and https.
MSDN has a great article with step-by-step instructions detailing how you can use the WebRequest class to send data. Link below:
http://msdn.microsoft.com/en-us/library/debx8sh9.aspx
Yes, there is a WebClient class. Look into documentation. There're some usful method to make GET and POST requests.