WebClient.UploadValues Post中文乱码的解决方法

使用WebClient.UploadValues Post中文时，会出现乱码的情况，设置Encoding属性不起作用，设置content-type也不起作用，最后只好自己用WebRequest来做：

//using (System.Net.WebClient wc = new System.Net.WebClient())
//{
//    wc.Encoding = Encoding.GetEncoding("GB2312");
//    NameValueCollection postData = new NameValueCollection();
//    postData.Add("UserIDText", userId.ToString());
//    postData.Add("UserNameText", userName);
//    postData.Add("ContentText", HttpUtility.UrlEncode(content,wc.Encoding));
//    postData.Add("UrlText", url);

//    wc.Headers.Add(HttpRequestHeader.ContentEncoding, "gb23112");
//    wc.Headers.Add(HttpRequestHeader.ContentType, "application/x-www-form-urlencoded");
//    wc.UploadValues(new Uri(postUrl),"POST", postData);
//}


Encoding myEncoding = Encoding.GetEncoding("gb2312");
string param = "UserIDText=" + HttpUtility.UrlEncode(userId.ToString(), myEncoding)
    + "&" + "UserNameText=" + HttpUtility.UrlEncode(userName, myEncoding)
    + "&" + "ContentText=" + HttpUtility.UrlEncode(content, myEncoding)
    + "&" + "UrlText=" + HttpUtility.UrlEncode(url, myEncoding);

byte[] postBytes = Encoding.ASCII.GetBytes(param);

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(postUrl);
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded;charset=gb2312";
req.ContentLength = postBytes.Length;

using (Stream reqStream = req.GetRequestStream())
{
    reqStream.Write(postBytes, 0, postBytes.Length);
}
using (WebResponse wr = req.GetResponse())
{
    //在这里对接收到的页面内容进行处理
}