c# - HttpWebResponse 的编码问题

Question

使用 Fiddler 运行以下代码显示加号正在转换为某种空白字符。我应该使用什么编码来防止数据被转换？我想保留加号等。

编辑:更新的代码示例

string postData = "test1=test+plussign&test2=another++twoplussigns";
private static byte[] EncodePostData(string postData)
{
    StringBuilder sb = new StringBuilder();

    string[] pairs = postData.Split('&');
    foreach (string pair in pairs)
    {
        string key = Uri.EscapeDataString(pair.Split('=')[0]);
        string value = Uri.EscapeDataString(pair.Split('=')[1]);

        sb.AppendFormat("{0}={1}&",key, value);
    }
    sb.Remove(sb.Length - 1, 1);

    return HttpUtility.UrlEncodeToBytes(sb.ToString());
}

调用方法如下

byte[] data = EncodePostData(postData);

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.UserAgent = "Mozilla/5.0 (X11; U; Linux i686; fr; rv:1.9.0.3) Gecko/2008092510 Ubuntu/8.04 (hardy) Firefox/3.03";
request.CookieContainer = cookies;
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
ServicePointManager.Expect100Continue = false;

Stream stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
stream.Close();

HttpWebResponse Response = (HttpWebResponse)request.GetResponse();
Response.Close();

Answer 1

由于您的变量名为 postData，我假设您正在向 Web 服务器发送 HTTP POST。

Wikipedia's summary HTTP POST 的规则是:

When a web browser sends a POST request from a web form element, the default Internet media type is "application/x-www-form-urlencoded". This is a format for encoding key-value pairs with possibly duplicate keys. Each key-value pair is separated by an '&' character, and each key is separated from its value by an '=' character. Keys and values are both escaped by replacing spaces with the '+' character and then using URL encoding on all other non-alphanumeric characters.

也就是说，HTTP POST 主体中 '+' 的默认解释是编码的 ' ' 字符。您需要通过调用 Uri.EscapeDataString 正确转义数据或 HttpUtility.UrlEncode .

Uri.EscapeDataString("test+PlusSigns"); // returns "test%2BPlusSigns"

或者，使用 HttpUtility.UrlEncodeToBytes并将生成的字节直接写入请求流(不使用 StreamWriter)。

(请注意，如果您要发送键/值对，则需要分别对每个键和值进行转义，然后使用 '=' 和 '&' 将它们连接起来字符。)