C# HTTPClient Form Post and Submit Issue

Question

I am trying to do some light screen scraping of a php site with a simple form to simplify a research portion of my work. The page has a simple form with three fields, and a submit button.

When I run my code the original page is returned as if I submitted nothing. I also tried to paste in the the fields as a ?name= etc... after the php url but that also returns me to the original page as if I had not pressed the submit button.

Here is my current code:

private async void postRequest(string url)
    {
        using (HttpClient client = new HttpClient())
        {
            var values = new List<KeyValuePair<string, string>>();
            values.Add(new KeyValuePair<string, string>("case_type", "55"));
            values.Add(new KeyValuePair<string, string>("petname", "singh"));
            values.Add(new KeyValuePair<string, string>("year", "2016"));
            values.Add(new KeyValuePair<string, string>("button", "Submit"));

            var content = new FormUrlEncodedContent(values);

            var response = await client.PostAsync(url, content);
            var responseString = await response.Content.ReadAsStringAsync();

            using (StreamWriter post = new StreamWriter("post_website.txt"))
            {
                post.WriteLine(responseString);
            }
        }
    }

Chrome Dev Tools screenshot after submit . I redacted parts of the url, it's a public information site, but being safe just in case.

I assume I am doing something wrong since I have basically taught myself C#, and this is my first time trying to do anything web related with C#.

I found a similar issue on StackOverflow here: Fill Form C# & Post Error , but this code didn't work either and I don't believe a cookie is needed. I have tried various other StackOverflow answers regarding using HttpClient and WebClient POST requests to the server, but none have worked.

Thanks in advance for any suggestions or insight.

Answer 1

lc put me onto the right path. I made some bad assumptions about what was receiving the form input. It's obvious now I should have tried the results page url as well. Time to go learn more php and web design I think.