HttpWebRequest多部分表单数据

时间:2010-12-31 22:04:26

标签: c# httpwebrequest httpwebresponse multipartform-data

我正在尝试将简单文本数据提交到多部分格式的CGI。

问题是..我不知道如何格式化表单数据!

简而言之,我的系统准备一个包含post数据的字符串,使用request.GetRequestStream()创建一个streamwriter,并直接将post字符串写入该streamwriter。然后它继续关闭编写器,并发送请求。

我已尝试将字符串格式化为:“Param1 = sometext& param2 = sometext”,但我收到错误:

Unhandled Exception: System.Net.WebException: The remote server returned an error: (417) Expectation Failed.
  at System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult result) [0x002d9] in /private/tmp/monobuild/build/BUILD/mono-2.8/mcs/class/System/System.Net/HttpWebRequest.cs:1425 
  at System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data) [0x00143] in /private/tmp/monobuild/build/BUILD/mono-2.8/mcs/class/System/System.Net/HttpWebRequest.cs:1250 

显然我正在格式化字符串错误,但我不能为我的生活弄清楚如何正确地做到这一点。

有人可以开导我吗? :)

编辑,我也尝试将request.ContentType = "application/x-www-form-urlencoded";更改为request.ContentType = "multipart/form-data";。这没有用,但我会这样离开。

编辑:完整代码:

public static string sendReq (string url, string pdata)//Pdata is the string containing form data
{
    StringBuilder sb  = new StringBuilder();
    byte[] buf = new byte[8192];
    HttpWebRequest request  = (HttpWebRequest) WebRequest.Create(url);
    CookieCollection jar = new CookieCollection();
    jar.Add(new Cookie("Cookie","Data","Removed","For privacy."));
    jar.Add(new Cookie("Cookie","Data","Removed","For privacy."));
    jar.Add(new Cookie("Cookie","Data","Removed","For privacy."));
    jar.Add(new Cookie("Cookie","Data","Removed","For privacy."));
    jar.Add(new Cookie("Cookie","Data","Removed","For privacy."));
    l("Loading cookie jar onto request");
    CookieContainer cont = new CookieContainer();
    cont.Add(jar);
    request.CookieContainer = cont;
    if (pdata != "")
    {
        request.Method = "POST";
        request.ContentType = "multipart/form-data;";
        request.ContentLength = pdata.Length;
        StreamWriter stOut = new StreamWriter(request.GetRequestStream(), System.Text.Encoding.ASCII);
        stOut.Write(pdata);
        stOut.Close();
    }
    HttpWebResponse response = (HttpWebResponse) request.GetResponse();
    Stream resStream = response.GetResponseStream();
    string tempString = null;
    int count = 0;
    do
    {
        count = resStream.Read(buf, 0, buf.Length);
        if (count != 0)
        {
            l("Data was read. ["+count+" bytes]. Encoding to ASCII");
            tempString = Encoding.ASCII.GetString(buf, 0, count);
            l("Appending to full string");
            sb.Append(tempString);
        }
    }
    while (count > 0);
    return sb.ToString();
}

处理发送帖子数据的代码部分:

if (pdata != "")
    {
        request.Method = "POST";
        request.ContentType = "multipart/form-data;";
        request.ContentLength = pdata.Length;
        StreamWriter stOut = new StreamWriter(request.GetRequestStream(), System.Text.Encoding.ASCII);
        stOut.Write(pdata);
        stOut.Close();
    }
    HttpWebResponse response = (HttpWebResponse) request.GetResponse();

1 个答案:

答案 0 :(得分:2)

尝试:

System.Net.ServicePointManager.Expect100Continue = false;

显然, HttpWebRequest 默认添加 Expect 标头,这会混淆很多服务器。

<强>更新

恢复为:

request.ContentType = "application/x-www-form-urlencoded";

因为内容类型和正文中数据的当前组合不匹配。