Submit an HTML form submit using C#

Question

I'm working on a school project which I want to see our timetable from our Windows8.1 devices with an universal app. So that I don't have to log in every time I want to check it. I need a method that logs me in to our school's website and lets me see the source code so I can see the lessons.

Website I need to log in with C# codes is here.

Source code seems like:

<form method="post" action="/adfs/ls/?SAMLRequest=nZJPb9swDMW/iqF7bMmt11SIU2QZihZosSBxd9hloG1m1WZJriglwT79lD9uM2DrYUeBj3yPP2py%0As9NdskFHypqSiZSzBE1jW2W%2Bl%2Bypuh2N2c10QqC7vJez4J/NEl8Ckk9ioyF5rJQsOCMtkCJpQCNJ%0A38jV7PFB5imXvbPeNrZjyYwInY9Wc2soaHQrdBvV4NPyoWTP3vcks0yrH4Z8aBWmv6D9qQympsug%0A77Mt1kSWJbfWNXgIU7I1dIQsuf9Usm8C4epacH6Zg/iQQ12PEQpx2dQXdcFbhCijBRCpDb41EgW8%0Aj4ZgfMlyLoqR4CN%2BUYmxFFzmeVoU119Zsjgt8VGZI5z3Nq6PIpJ3VbUYLT6vKpZ8GSBHATshlQd3%0Ad87y/cEwAGTTAdfACNvQBPoT1SQ7t3m94%2BmE2B4Yxlt43PlkbnUPTtE%2Bo4ad0kG/5jwXzruYYonr%0A/0q9l62xRQf7t4Q4F41XzfG5jdzslobYf3Odnor/2OKtfP5Zp78B&amp;RelayState=Zadkine" id="MainForm">
<input name="ctl00$ContentPlaceHolder1$UsernameTextBox" type="text" id="ContentPlaceHolder1_UsernameTextBox" />
<input name="ctl00$ContentPlaceHolder1$PasswordTextBox" type="password" id="ContentPlaceHolder1_PasswordTextBox" />
<input type="submit" name="ctl00$ContentPlaceHolder1$SubmitButton" value="Aanmelden" id="ContentPlaceHolder1_SubmitButton" class="Resizable" />
</form>

This is it, basically. There are some __VIEWSTATE's but I don't know if they matter.

I found 2 type of solutions.

1. WebRequest examples here on Stack Overflow which didn't work :/

       HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://sts.zadkine.nl/adfs/ls/?SAMLRequest=nZJPb9swDMW/iqF7bMmt11SIU2QZihZosSBxd9hloG1m1WZJriglwT79lD9uM2DrYUeBj3yPP2py%0As9NdskFHypqSiZSzBE1jW2W%2Bl%2Bypuh2N2c10QqC7vJez4J/NEl8Ckk9ioyF5rJQsOCMtkCJpQCNJ%0A38jV7PFB5imXvbPeNrZjyYwInY9Wc2soaHQrdBvV4NPyoWTP3vcks0yrH4Z8aBWmv6D9qQympsug%0A77Mt1kSWJbfWNXgIU7I1dIQsuf9Usm8C4epacH6Zg/iQQ12PEQpx2dQXdcFbhCijBRCpDb41EgW8%0Aj4ZgfMlyLoqR4CN%2BUYmxFFzmeVoU119Zsjgt8VGZI5z3Nq6PIpJ3VbUYLT6vKpZ8GSBHATshlQd3%0Ad87y/cEwAGTTAdfACNvQBPoT1SQ7t3m94%2BmE2B4Yxlt43PlkbnUPTtE%2Bo4ad0kG/5jwXzruYYonr%0A/0q9l62xRQf7t4Q4F41XzfG5jdzslobYf3Odnor/2OKtfP5Zp78B&RelayState=Zadkine");
       request.Method = "POST";
       request.ContentType = "application/x-www-form-urlencoded";
       using (var requestStream = request.GetRequestStream())
       using (var writer = new StreamWriter(requestStream))
       {
           writer.Write("ctl00$ContentPlaceHolder1$UsernameTextBox=" + yourusername + "&ctl00$ContentPlaceHolder1$PasswordTextBox=" + yourpassword);
       }
       using (var responseStream = request.GetResponse().GetResponseStream())
       using (var reader = new StreamReader(responseStream))
       {
           var result = reader.ReadToEnd();
           richTextBox1.Text = result;
       }
   

In another websites, if I try this code, I get an error like "You have to allow cookies to login." but on the website of my school I don't get any, not even "Wrong password". (If I type wrong password on a browser, I get the wrong password error.)

2. Duplicating the form to an .HTML file and use WebView to log in with JavaScript. If I try this, I get redirected to another page and get a very weird error like "User null couldn't recognized". So these 2 type of solutions didn't work for me.

So, the question is, how can I log in to website with C# ?

Answer 1

Example code in WebBrowser document completed event:

HtmlElement element;
// Filling the username
element = webBrowser.Document.GetElementById("ContentPlaceHolder1_UsernameTextBox");
if (element != null)
{
    element.InnerText = "username";
}


// In case if there is no id of the input field you can get it by name
HtmlElementCollection elements = null;
elements = webBrowser.Document.All.GetElementsByName("pass");
element = elements[0];
element.InnerText = "password";

//login (click)
elements = webBrowser.Document.All.GetElementsByName("submit");
element  = elements[0];
element.InvokeMember("CLICK");