如何使用c#提交http表单

I have a simple html file such as

我有一个简单的html文件，比如

<form action="http://www.someurl.com/page.php" method="POST">
   <input type="text" name="test"><br/>
   <input type="submit" name="submit">
</form>

Edit: I may not have been clear enough with the question

编辑:我可能对这个问题不够清楚

I want to write C# code which submits this form in the exact same manner that would occur had I pasted the above html into a file, opened it with IE and submitted it with the browser.

我想编写c#代码，它以与将上面的html粘贴到一个文件中、用IE打开并通过浏览器提交时完全相同的方式提交这个表单。

6 个解决方案

#1

Here is a sample script that I recently used in a Gateway POST transaction that receives a GET response. Are you using this in a custom C# form? Whatever your purpose, just replace the String fields (username, password, etc.) with the parameters from your form.

下面是一个示例脚本，我最近在网关POST事务中使用了一个GET响应。您是否在自定义c#表单中使用它?无论您的目的是什么，只要用表单中的参数替换字符串字段(用户名、密码等)即可。

private String readHtmlPage(string url)
   {

    //setup some variables

    String username  = "demo";
    String password  = "password";
    String firstname = "John";
    String lastname  = "Smith";

    //setup some variables end

      String result = "";
      String strPost = "username="+username+"&password="+password+"&firstname="+firstname+"&lastname="+lastname;
      StreamWriter myWriter = null;

      HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
      objRequest.Method = "POST";
      objRequest.ContentLength = strPost.Length;
      objRequest.ContentType = "application/x-www-form-urlencoded";

      try
      {
         myWriter = new StreamWriter(objRequest.GetRequestStream());
         myWriter.Write(strPost);
      }
      catch (Exception e) 
      {
         return e.Message;
      }
      finally {
         myWriter.Close();
      }

      HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
      using (StreamReader sr = 
         new StreamReader(objResponse.GetResponseStream()) )
      {
         result = sr.ReadToEnd();

         // Close and clean up the StreamReader
         sr.Close();
      }
      return result;
   } 

#2

Your HTML file is not going to interact with C# directly, but you can write some C# to behave as if it were the HTML file.

您的HTML文件不会直接与c#交互，但是您可以编写一些c#，使其表现为HTML文件。

For example: there is a class called System.Net.WebClient with simple methods:

例如:有一个类叫做System.Net。WebClient用简单方法:

using System.Net;
using System.Collections.Specialized;

...
using(WebClient client = new WebClient()) {

    NameValueCollection vals = new NameValueCollection();
    vals.Add("test", "test string");
    client.UploadValues("http://www.someurl.com/page.php", vals);
}

For more documentation and features, refer to the MSDN page.

有关更多文档和特性，请参阅MSDN页面。

#3

You can use the HttpWebRequest class to do so.

您可以使用HttpWebRequest类来这样做。

Example here:

例子:

using System;
using System.Net;
using System.Text;
using System.IO;


    public class Test
    {
        // Specify the URL to receive the request.
        public static void Main (string[] args)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create (args[0]);

            // Set some reasonable limits on resources used by this request
            request.MaximumAutomaticRedirections = 4;
            request.MaximumResponseHeadersLength = 4;
            // Set credentials to use for this request.
            request.Credentials = CredentialCache.DefaultCredentials;
            HttpWebResponse response = (HttpWebResponse)request.GetResponse ();

            Console.WriteLine ("Content length is {0}", response.ContentLength);
            Console.WriteLine ("Content type is {0}", response.ContentType);

            // Get the stream associated with the response.
            Stream receiveStream = response.GetResponseStream ();

            // Pipes the stream to a higher level stream reader with the required encoding format. 
            StreamReader readStream = new StreamReader (receiveStream, Encoding.UTF8);

            Console.WriteLine ("Response stream received.");
            Console.WriteLine (readStream.ReadToEnd ());
            response.Close ();
            readStream.Close ();
        }
    }

/*
The output from this example will vary depending on the value passed into Main 
but will be similar to the following:

Content length is 1542
Content type is text/html; charset=utf-8
Response stream received.
<html>
...
</html>

*/

#4

Response.Write("<script> try {this.submit();} catch(e){} </script>");

#5

I had a similar issue in MVC (which lead me to this problem).

我在MVC中遇到了类似的问题(这导致了我遇到了这个问题)。

I am receiving a FORM as a string response from a WebClient.UploadValues() request, which I then have to submit - so I can't use a second WebClient or HttpWebRequest. This request returned the string.

我正在接收来自WebClient. uploadvalues()请求的字符串响应，然后必须提交该请求——因此我不能使用第二个WebClient或HttpWebRequest。这个请求返回了字符串。

using (WebClient client = new WebClient())
  {
    byte[] response = client.UploadValues(urlToCall, "POST", new NameValueCollection()
    {
        { "test", "value123" }
    });

    result = System.Text.Encoding.UTF8.GetString(response);
  }

My solution, which could be used to solve the OP, is to append a Javascript auto submit to the end of the code, and then using @Html.Raw() to render it on a Razor page.

我的解决方案(可用于解决OP)是将Javascript自动提交附加到代码的末尾，然后使用@Html.Raw()在Razor页面上呈现它。

result += "<script>self.document.forms[0].submit()</script>";
someModel.rawHTML = result;
return View(someModel);

Razor Code:

剃须刀代码:

@model SomeModel

@{
    Layout = null;
}

@Html.Raw(@Model.rawHTML)

I hope this can help anyone who finds themselves in the same situation.

我希望这能帮助那些处于同样处境的人。

#6

I needed to have a button handler that created a form post to another application within the client's browser. I landed on this question but didn't see an answer that suited my scenario. This is what I came up with:

我需要一个按钮处理程序，它在客户端浏览器中为另一个应用程序创建表单post。我回答了这个问题，但没有找到适合我的答案。这就是我想到的:

      protected void Button1_Click(object sender, EventArgs e)
        {

            var formPostText = @"<html><body><div>
<form method=""POST"" action=""OtherLogin.aspx"" name=""frm2Post"">
  <input type=""hidden"" name=""field1"" value=""" + TextBox1.Text + @""" /> 
  <input type=""hidden"" name=""field2"" value=""" + TextBox2.Text + @""" /> 
</form></div><script type=""text/javascript"">document.frm2Post.submit();</script></body></html>
";
            Response.Write(formPostText);
        }