通过两次单击从.aspx网页获取数据c＃.net

Question

I am a novice in programming. I have a project where I have to get data from a website (I ll be posting the website below). But it happens that I first have to select a date and press a 'Go' button and then click on another Button/Link 'View in Excel' to download this data. I cannot find a way to first click the 'Go' button after selecting my required date and then click the second button 'View in Excel' through my c# code. Any help will be appreciated.

PS: You can check the link for yourselves http://www.mcxindia.com/sitepages/BhavCopyDateWiseArchive.aspx

private void Form1_Load(object sender, EventArgs e)
    {
        WebClient webClient = new WebClient();

        byte[] b = webClient.DownloadData("http://www.mcxindia.com/sitepages/BhavCopyDatewise.aspx");

        string s = System.Text.Encoding.UTF8.GetString(b);

        var __EVENTVALIDATION = ExtractVariable(s, "__EVENTVALIDATION");

        //__EVENTVALIDATION.Dump();

        var forms = new NameValueCollection();

        forms["__EVENTTARGET"] = "btnLink_Excel";
        forms["__EVENTARGUMENT"] = "";
        forms["__VIEWSTATE"] = ExtractVariable(s, "__VIEWSTATE");
        forms["mTbdate"] = "01%2F15%2F2013";
        forms["__EVENTVALIDATION"] = __EVENTVALIDATION;

        webClient.Headers.Set(HttpRequestHeader.ContentType, "application/x-www-form-urlencoded");

        var responseData = webClient.UploadValues(@"http://www.mcxindia.com/sitepages/BhavCopyDatewise.aspx", "POST", forms); 
        System.IO.File.WriteAllBytes(@"c:\11152011.csv", responseData);
    }

    private static string ExtractVariable(string s, string valueName)
    {   
        string tokenStart = valueName + "\" value=\"";
        string tokenEnd = "\" />";

        int start = s.IndexOf(tokenStart) + tokenStart.Length;
        int length = s.IndexOf(tokenEnd, start) - start;
        return s.Substring(start, length);
    }

The above code gives me the file only for the last available date. I am not able to get it for the date I want.

Answer 1

Seems like you need to made a HTTP Post request with one post data (date). This should be easy enough. Have a look at this question and see if it helps you. Send HTTP Post Request through ASP.net

Answer 2

I found a solution to this question. pls see here