3

所以遇到了一个小问题。我正在创建一个小型应用程序来自动在一个网站上提交表单。但不好的是，他们为此使用了 multipart/form-data。没有文件上传只是一些文本字段供提交。

当然这样做会失败。

string postData1 = "firstfield="+firststring+"secondfield="+secondstring;

所以我的问题是如何用多部分表单发布这些表单字段？

像这样在php中发布类似的数组：

$postdata = array('firstfield' => $firststring, 'secondfield' => $secondstring);

工作并通过表单，但似乎不适用于 c#

有什么建议么？

数据提交通过 3 页（基本屏幕截图）登录/part1/part2

到目前为止，我可以成功登录并发布第 1 部分（使用普通应用程序/x-www-form-urlencoded 表单）

但是，当我尝试发布多部分表单时，它会失败并将我送回第 1 部分。所以也许我的代码错了，但这里是：

string password = "password";
string username = "username";
string link = "http://somelink.com/";
string text = "Blah Blah some text here";
string title = "Blah Blah";
string tags1 = title;
string summary = "Blah Blah summary";
string tags = tags1.Replace(" ", ",");

// Set cookie container
CookieContainer cookieJar = new CookieContainer();

string loginData = "username=" + username + "&password=" + password + "&processlogin=1&return=%2Fsubmit.php";

HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://loginlink.com/login.php");
myRequest.Method = "POST";
        myRequest.ServicePoint.Expect100Continue = false;
myRequest.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.4) Gecko/20091016 Firefox/3.5.4 GTB6 (.NET CLR 3.5.30729)";
myRequest.Timeout = 10000;
myRequest.ContentType = "application/x-www-form-urlencoded";
myRequest.ContentLength = loginData.Length;
myRequest.CookieContainer = cookieJar;
myRequest.KeepAlive = true;
myRequest.AllowAutoRedirect = true;

//Write post data to stream
StreamWriter myWriter = new StreamWriter(myRequest.GetRequestStream());
myWriter.Write(loginData);
myWriter.Close();

// Get the response.
HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();

// Open the stream using a StreamReader for easy access.
StreamReader myReader = new StreamReader(myResponse.GetResponseStream());
// Read the content.
string output = myReader.ReadToEnd();

// Clean up the streams and the response.
myReader.Close();
myResponse.Close();


Match matchkey = Regex.Match(output, "type=\"hidden\" name=\"randkey\" value=\"([^\"]+)\"", RegexOptions.IgnoreCase);
string key1 = matchkey.Groups[1].Value;
Match matchid = Regex.Match(output, "type=\"hidden\" name=\"id\" value=\"([^\"]+)\"", RegexOptions.IgnoreCase);
string id1 = matchid.Groups[1].Value;


string postData = "url=" + link + "&phase=1&randkey=" + key1 + "&id=" + id1;

HttpWebRequest myRequest2 = (HttpWebRequest)WebRequest.Create("http://submitpage1.com/submit.php");
myRequest2.Method = "POST";
myRequest2.ServicePoint.Expect100Continue = false;
myRequest2.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.4) Gecko/20091016 Firefox/3.5.4 GTB6 (.NET CLR 3.5.30729)";
myRequest2.Timeout = 10000;
myRequest2.ContentType = "application/x-www-form-urlencoded";
myRequest2.ContentLength = postData.Length;
myRequest2.CookieContainer = cookieJar;
myRequest2.KeepAlive = true;
myRequest2.AllowAutoRedirect = true;


//Write post data to stream
StreamWriter myWriter2 = new StreamWriter(myRequest2.GetRequestStream());
myWriter2.Write(postData);
myWriter2.Close();

// Get the response.
HttpWebResponse myResponse2 = (HttpWebResponse)myRequest2.GetResponse();

// Open the stream using a StreamReader for easy access.
StreamReader myReader2 = new StreamReader(myResponse2.GetResponseStream());
// Read the content.
string output1 = myReader2.ReadToEnd();

// Clean up the streams and the response.
myReader2.Close();
myResponse2.Close();

Match matchkey1 = Regex.Match(output1, "type=\"hidden\" name=\"randkey\" value=\"([^\"]+)\"", RegexOptions.IgnoreCase);
string key2 = matchkey1.Groups[1].Value;
Match matchid1 = Regex.Match(output1, "type=\"hidden\" name=\"randkey\" value=\"([^\"]+)\"", RegexOptions.IgnoreCase);
string id2 = matchid1.Groups[1].Value;

string boundary = "-----------------------------1721856231228";

// Build up the post
StringBuilder sb = new StringBuilder();
sb.Append("\r\n" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"title\"" + "\r\n");
sb.Append("\r\n");
sb.Append(title);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"tags\"" + "\r\n");
sb.Append("\r\n");
sb.Append(tags);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"bodytext\"" + "\r\n");
sb.Append("\r\n");
sb.Append(text);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"summarycheckbox\"" + "\r\n");
sb.Append("\r\n");
sb.Append("on");
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"summarytext\"" + "\r\n");
sb.Append("\r\n");
sb.Append(summary);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"remLen\"" + "\r\n");
sb.Append("\r\n");
sb.Append("125");
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"category\"" + "\r\n");
sb.Append("\r\n");
sb.Append("1");
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"trackback\"" + "\r\n");
sb.Append("\r\n");
sb.Append("");
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"url\"" + "\r\n");
sb.Append("\r\n");
sb.Append(link);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"phase\"" + "\r\n");
sb.Append("\r\n");
sb.Append("2");
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"randkey\"" + "\r\n");
sb.Append("\r\n");
sb.Append(key2);
sb.Append("\r\n--" + boundary + "\r\n");
sb.Append("Content-Disposition: form-data; name=\"id\"" + "\r\n");
sb.Append("\r\n");
sb.Append(id2);
sb.Append("\r\n--" + boundary + "--" + "\r\n");

string postData1 = sb.ToString();

HttpWebRequest myRequest3 = (HttpWebRequest)WebRequest.Create("http://submitpage2.com/submit.php");
myRequest3.Method = "POST";
myRequest3.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.4) Gecko/20091016 Firefox/3.5.4 GTB6 (.NET CLR 3.5.30729)";
myRequest3.Timeout = 10000;
myRequest3.ServicePoint.Expect100Continue = false;
myRequest3.Referer = "http://bookmarkindo.com/submit.php";
myRequest3.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
myRequest3.ContentType = "multipart/form-data; boundary=" + boundary;
myRequest3.ContentLength = postData1.Length;
myRequest3.CookieContainer = cookieJar;
myRequest3.KeepAlive = true;
myRequest3.AllowAutoRedirect = true;

//Write out postdata
StreamWriter myWriter3 = new StreamWriter(myRequest3.GetRequestStream());
myWriter3.Write(postData1);
myWriter3.Close();

// Get the response.
HttpWebResponse myResponse3 = (HttpWebResponse)myRequest3.GetResponse();

// Open the stream using a StreamReader for easy access.
StreamReader myReader3 = new StreamReader(myResponse3.GetResponseStream());
// Read the content.
string output2 = myReader3.ReadToEnd();

// Clean up the streams and the response.
myReader3.Close();
myResponse3.Close();

欢迎所有建议

4

4 回答 4

6

posts os multipart/form-data type have a different structure because they are meant to transfer data and not just plain text.

Here's the format:

--[random number, a GUID is good here]
Content-Disposition: form-data; name="[name of variable]"

[actual value]
--[random number, a GUID is good here]--

Using HTTPWebRequest you can create a request that has that format. Here's a sample:

string boundary = Guid.NewGuid().ToString();
string header = string.Format("--{0}", boundary);
string footer = string.Format("--{0}--", boundary);

StringBuilder contents = new StringBuilder();
contents.AppendLine(header);

contents.AppendLine(header);
contents.AppendLine(String.Format("Content-Disposition: form-data; name=\"{0}\"", "username"));
contents.AppendLine();
contents.AppendLine("your_username");

contents.AppendLine(header);
contents.AppendLine(String.Format("Content-Disposition: form-data; name=\"{0}\"", "password"));
contents.AppendLine();
contents.AppendLine("your_password");

contents.AppendLine(footer);
于 2010-01-09T22:49:28.823 回答
3

Here is an article on multipart form posts in C# with more detail. This code was eventually merged into RestSharp, which is an excellent library you could use to generate the request.

于 2012-01-20T17:03:36.770 回答
3

在 C# 中发送多部分表单数据的最佳方式显示在片段中，在这里您可以看到添加不同类型的内容就像将其添加到包装器多部分内容类型一样简单：

var documentContent = new MultipartFormDataContent();
documentContent.Add(new StringContent("AnalyticsPage.xlsx"), "title");
documentContent.Add(new ByteArrayContent(File.ReadAllBytes("C:\\Users\\awasthi\\Downloads\\AnalyticsPage.xlsx")), "file", "AnalyticsPage.xlsx");

然后只需进行 api 调用：

using (var client = new HttpClient(new HttpClientHandler() { UseDefaultCredentials = true, CookieContainer = new CookieContainer() }))
{
  response = client.PostAsync(documentAddApi, documentContent).Result;
  var responseContent = response.Content.ReadAsStringAsync().Result;
 }

这里的期望是您正在调用的其余端点正在接受文件的“标题”字段和名为“文件”的文件的字节数组。

于 2019-01-04T13:30:30.120 回答
0

The format of multipart/form-data requests is outlined here: http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2.

于 2010-01-09T22:53:02.800 回答