使用 HttpWebRequest 發布表單數據

Question

我想將一些表單數據發布到不在我自己的 web 應用程序中的指定 URL 中。 它具有相同的域，例如“domain.client.nl”。 web 應用程序有一個 url "web.domain.client.nl" 和 url 我要發布到的地方是 "idp.nl"client. 但是我的代碼什么也沒做......有人知道我做錯了什么嗎？

沃特

StringBuilder postData = new StringBuilder();
postData.Append(HttpUtility.UrlEncode(String.Format("username={0}&", uname)));
postData.Append(HttpUtility.UrlEncode(String.Format("password={0}&", pword)));
postData.Append(HttpUtility.UrlEncode(String.Format("url_success={0}&", urlSuccess)));
postData.Append(HttpUtility.UrlEncode(String.Format("url_failed={0}", urlFailed)));

ASCIIEncoding ascii = new ASCIIEncoding();
byte[] postBytes = ascii.GetBytes(postData.ToString());

// set up request object
HttpWebRequest request;
try
{
    request = (HttpWebRequest)HttpWebRequest.Create(WebSiteConstants.UrlIdp);
}
catch (UriFormatException)
{
    request = null;
}
if (request == null)
    throw new ApplicationException("Invalid URL: " + WebSiteConstants.UrlIdp);

request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postBytes.Length;
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";

// add post data to request
Stream postStream = request.GetRequestStream();
postStream.Write(postBytes, 0, postBytes.Length);
postStream.Flush();
postStream.Close();

Answer 1

字段名和值都應該是 url 編碼的。 帖子數據和查詢字符串的格式相同

.net 的做法是這樣的

NameValueCollection outgoingQueryString = HttpUtility.ParseQueryString(String.Empty);
outgoingQueryString.Add("field1","value1");
outgoingQueryString.Add("field2", "value2");
string postdata = outgoingQueryString.ToString();

這將負責對字段和值名稱進行編碼

Answer 2

試試這個：

var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx");

var postData = "thing1=hello";
    postData += "&thing2=world";
var data = Encoding.ASCII.GetBytes(postData);

request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;

using (var stream = request.GetRequestStream())
{
    stream.Write(data, 0, data.Length);
}

var response = (HttpWebResponse)request.GetResponse();

var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();

Answer 3

您對表單的編碼不正確。 您應該只對值進行編碼：

StringBuilder postData = new StringBuilder();
postData.Append("username=" + HttpUtility.UrlEncode(uname) + "&");
postData.Append("password=" + HttpUtility.UrlEncode(pword) + "&");
postData.Append("url_success=" + HttpUtility.UrlEncode(urlSuccess) + "&");
postData.Append("url_failed=" + HttpUtility.UrlEncode(urlFailed));

編輯

我錯了。 根據RFC1866 第 8.2.1 節，名稱和值都應該被編碼。

但是對於給定的示例，名稱沒有任何需要編碼的字符，因此在這種情況下，我的代碼示例是正確的；)

問題中的代碼仍然不正確，因為它會對等號進行編碼，這就是 Web 服務器無法對其進行解碼的原因。

更合適的方法是：

StringBuilder postData = new StringBuilder();
postData.AppendUrlEncoded("username", uname);
postData.AppendUrlEncoded("password", pword);
postData.AppendUrlEncoded("url_success", urlSuccess);
postData.AppendUrlEncoded("url_failed", urlFailed);

//in an extension class
public static void AppendUrlEncoded(this StringBuilder sb, string name, string value)
{
    if (sb.Length != 0)
        sb.Append("&");
    sb.Append(HttpUtility.UrlEncode(name));
    sb.Append("=");
    sb.Append(HttpUtility.UrlEncode(value));
}

Answer 4

使用此代碼：

internal void SomeFunction() {
    Dictionary<string, string> formField = new Dictionary<string, string>();
    
    formField.Add("Name", "Henry");
    formField.Add("Age", "21");
    
    string body = GetBodyStringFromDictionary(formField);
    // output : Name=Henry&Age=21
}

internal string GetBodyStringFromDictionary(Dictionary<string, string> formField)
{
    string body = string.Empty;
    foreach (var pair in formField)
    {
        body += $"{pair.Key}={pair.Value}&";   
    }

    // delete last "&"
    body = body.Substring(0, body.Length - 1);

    return body;
}

Answer 5

List<KeyValuePair<string, string>> formField= new List<KeyValuePair<string,string>>();

formField.Add(new KeyValuePair<string, string>("Name", "Henry"));
formField.Add(new KeyValuePair<string, string>("Age", "21"));

var body = string.Join("&", formField.Select(kvp => $"{kvp.Key}={kvp.Value}"));