0

I'm trying to get the HTML source as string from the following website:

https://physics.nist.gov/cgi-bin/cuu/CCValue?mal|ShowSecond=Browse&First=malc2

But when I'm using WebClient in C#:

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
WebClient client = new WebClient();
string s = client.DownloadString("https://physics.nist.gov/cgi-bin/cuu/CCValue?mal|ShowSecond=Browse&First=malc2");

I'm getting back you have supplied an ill-formed request from the website and not the correlation coefficient I'm looking for.

I took as well a look at the following question How to post data to specific URL using WebClient in C# but it didn't helped me.

I think the problem has to do with the | character in the URL. If you click on the link above it doesn't work because the | is replaced by %7C.

System.Diagnostics.Process.Start(url) opens the correct page in a browser.

See https://dotnetfiddle.net/wAYWEu

Update

Using Wireshark and switching to http I can see that the | character gets replaced by %7C.

144 2.241432    10.131.36.167   195.176.26.193  HTTP    253 GET http://physics.nist.gov/cgi-bin/cuu/CCValue?mal%7CShowSecond=Browse&First=malc2 HTTP/1.1

How can I avoid that?

Improve this question
5
  • what options you selected in the form that gives that url? Commented Jun 22, 2022 at 12:03
  • physics.nist.gov/cuu/Correlations/index.html then alpha particle mass energy equivalent and alpha particle mass. Commented Jun 22, 2022 at 12:08
  • There's a difference between the UploadString referred to in the question you linked to and the DownloadString method you're calling in your code. Commented Jun 22, 2022 at 12:16
  • @phuzi I tried it as well with UploadString and separating the URL and parameters. No success. Commented Jun 22, 2022 at 12:17
  • 1
    @Wollmich You should use HttpClient nowdays instead of WebClient. Even Microsoft recommends this. Anyway, I think you are out of luck, it seems it is the service that is not doing a proper job handling the querystring-parameters. The request physics.nist.gov/cgi-bin/cuu/… should work if they did a proper decoding on their end. Commented Jun 23, 2022 at 5:54
Related questions
0
WebClient.DownloadString() Not Producing Exact HTML
3
Get html that is generated via AJAX in webclient
2
I am trying to retrieve a webpage html with webclient and display it with webbrowser in C#
Load 7 more related questions Show fewer related questions

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.