c#以编程方式提交多部分/表单数据

所以有个小问题。我正在创建一个小应用程序，在一个网站上自动提交表单。但糟糕的是，他们正在为此使用多部分/表单数据。 没有文件上传，只有一些文本字段供提交

当然，这样做是失败的

string postData1=“firstfield=“+firststring+”secondfield=“+secondstring；

所以我的问题是他妈的如何用多部分表单发布这些表单字段

在php中发布类似数组，如下所示：

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

工作并通过表单，但似乎不使用c#

有什么建议吗

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数据提交需要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）

但当我尝试发布多部分表单时，它失败了，并将我发送回第1部分。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

发布操作系统多部分/表单数据类型具有不同的结构，因为它们旨在传输数据，而不仅仅是纯文本

以下是格式：

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

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

使用HTTPWebRequest，您可以创建具有该格式的请求。以下是一个示例：

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);

---

这里概述了

多部分/表单数据请求的格式：。
这里有一篇更详细的文章。这段代码最终被合并到一个优秀的库中，您可以使用它来生成请求。
用C#发送多部分表单数据的最佳方法如代码片段所示，在这里您可以看到添加不同类型的内容与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rest端点正在接受文件的“title”字段和名为“file”的文件的字节数组